Our Philippine House Project – Roof and Roofing

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What we’ve learned about roofing systems, roof trusses, roofing materials and cost of roofing in the Philippines as part of our house building project.

roof_illustrate

Roofing systems have become very standardized in the Philippines.  What we describe here is the roof system that goes on most houses except the very high end such as real clay tile or cement tile, a few asphalt shingle roofs and the Nipa or sheet steel roofs of the ordinary “bahay” – native house.

Concrete Roofs. See THIS POST

We have drawn some conclusions from Typhoon Yolanda damage in Tacloban, including ways that our roof could be made more typhoon resistant.  See http://myphilippinelife.com/lessons-from-yolanda-building-construction/

Metal Roof Basics.  Steel trusses of various designs rise from the topmost concrete roof beam.  The trusses are welded to stubs of rebar protruding through and well anchored in the concrete roof beam.  (One reader suggests that this is inadequate.  See comments below)

The trusses are almost always welded-up on-site and then primed.  It’s best to use one of the two part epoxy primers, especially if you’re anywhere near the sea.  We used Boysen Red Oxide Epoxy Primer which we bought from Iloilo City Hardware on Iznart Street in Iloilo City.  The cost was P603 per gallon.  You get two cans per gallon, the primer and a smaller can of  hardener.  You’ll also have to buy epoxy reducer, an expensive thinner for epoxy.  The reducer is about P420 per gallon.  Some of my crew members tended to waste the reducer, especially trying to clean brushes. Finally, I learned to buy cheap brushes which could be discarded.  Once the hardener is mixed into the primer, it very difficult to clean brushes.  There are cheaper epoxy primers, but we’re impressed with the Boysen.

Roof is going 4-10-10

Roof is going up 4-10-10.  This photo shows the perimeter wall, the carport, the bahay kubo and my “office”.

Metal trusses of of various designs rise from the roof beam which top the hollow block walls.  The trusses are welded to stubs of rebar previously embedded in the roof beam for that purpose.  This system seems to work.  We did not see any roofs of this type blown off during Typhoon Frank in Iloilo City.  Here you see four 12mm rebar wrapped around the truss and welded in place.   In total, the roof is held on by at least thirty such rebars.

roofing_attachment_3

Our roof  trusses were a bit unusual.  Most trusses use the interior walls of the house for support so that the spans are shorter.  This requires less steel and saves money.  Our trusses were designed so that they could span the entire house without support — sort of like what you’d see in a basketball court or warehouse.  This would allow us to have quite a lot of open space in the attic, although we never requested this and are unlikely to use the attic space.

Making roof rafters in our new on-site welding shop

Making roof rafters in our on-site welding shop

The center girt is 40cm wide and is welded up from 2″ x 2″ angle bar, 5mm for the frame and 3mm for the webbing.  The 35cm wide rafters use the same angle bar.

Originally, the height of our roof from the top of the wall to the peak of the roof girt was to be 2.5 meters.  We put up the center girt and two rafters and the roof pitch just looked too low.  On the spot, we decided to increase the roof height to 3.0 meters This what’s possible when you’re running your own crew, but such decisions, if they’re not carefully thought out, can have ramifications you’ve not yet imagined.  In this case we seem to have gotten away with this snap decision.  Of course the steeper roof meant more roof area and more roofing materials.

3-23-10 The first rafter goes up and we decide on more roof pitch.

3-23-10 The center girt and first rafter go up and we decide on more roof pitch.

Turnbuckles welded to rebar are used to bring rafters into alighnment before purlins are attached. Also shown are collar ties at the peak of the roof.

Turnbuckles welded to rebar are used to bring rafters into alighnment before purlins are attached. Also shown are collar ties at the peak of the roof.

Once the trusses and or rafters are in place, a system of lightweight steel purlins are installed perpendicularly across the rafters.  The purlins can be initially first pop-riveted to the rafters, then when the all adjustments have been made, welded to them. These are our 2″ x 3″ 1.2mm roof purlins.  They all have to be painted with epoxy primer.  We paid P400 each for them in April 2010 but steel prices are going up rapidly.  Our roof needed 85 of these purlins.  They are spaced between 50 and 60CM apart.  You have to be very careful when shopping for purlins to make sure the material is not substandard in thickness.

2" x 3" roof purlins

Purlins are welded to rafters using scraps of angle bar

Purlins are welded to rafters using scraps of angle bar

Roof structure

Roof structure

This photo shows the purlins installed across the rafters (trusses). The photo really shows all the elements of the roof structure; the 40cm center girt at the ridge, the 35cm rafters, the collar beams and the purlins.  Next comes the facia and soffit frames.

The purlins support the long span steel roofing, but before the roof itself is put on, a metal  “facia frame” is installed around the perimeter of the roof.  Our frame is welded up of 1″ x 1″ angle bar and 1″ flat bar.  This frame supports and is hidden by a metal facia “board”. The facia frame may also supports the soffit.  At the rakes, the facia frame is welded to ends of the purlins.  At the eves they can be welded across the rafter tails.  The facia frame is the structural heart of the Philippine roof cornice system.

A simple roof

A simple roof

This is a photo of a very simple roof.  It shows the scalloped prefabricated steel facia, the prefab gutter attached to the facia and the red oxide primed purlins supporting the unpainted galvanized roofing.  On simple buildings like this one, pop rivets hold things together.

Shown here are small samples of the standard facia "board" and the gutter used in Philippine metal roofing.

Shown here are small samples of the standard facia “board” (left) and the gutter (right) used in Philippine metal roofing.

Here are the metal facia and the gutter positioned on a facia frame.

Here are the metal facia and the gutter positioned on a facia frame.

Once the purlins, facia and soffit frames, facia board and gutters are in place, the long span roofing can be screwed to the purlins using self-tapping tek screws.  This is usually done by a crew working for the company which sells the roofing.  “Long span” means that the roofing sheets are long enough to reach from eave to peak without joints. Once the roofing is on, the matching ridge caps and any other accessories go on.

Soffit and facia frames

Soffit and facia frames

This photo shows the soffit frame (below) and the facia frame. The soffit frame is constructed of 1½ x 1½” 1/8″ (2mm) angle bar.  This angle bar is P305 for a 6 meter length. It’s cheaper than wood.  We used a 60cm x 120cm framework of this angle bar for our entire ceiling structure.

To recap; a system of lightweight steel purlins are installed perpendicular to the trusses.  The purlins provide support for the long span steel roofing which is screwed to the purlins using “tek” screws.  The other parts of this standardized system are a steel frame welded to the ends of the rafter tails.  This “facia frame” extends around the entire roof edge.  A pre-painted steel facia “board” is attached to and covers the facia frame.  Then pre-painted, decorative gutter is attached to the facia board.  The installation of the facia frame, facia board and gutter allow the tweaks and adjustments so that the final roof installation can proceed smoothly.

These roofing systems are generally available in .4, .5  and .6mm thickness. Generally .4mm is used as it’s the least expensive.  We originally ordered .5mm for the roofing and .6mm for the gutters but it was not available so we had to order .6mm at a considerably higher price.  This has proved to be a blessing.  If you can afford it, the .6mm roofing is very worthwhile.  The .4mm roofing is rather easily damaged by workers and ladders and rusts out more quickly.   Our roofing is said to be “Galvalume” coated, that is coated with a mixture of aluminum and zinc which is supposed to be more durable than ordinary galvanized steel.  Supposedly the paint is applied in a Taiwan factory.  This 6mm material is widely used in roofing commercial buildings.

May 5, 2010 roofing arrives. Completed roof structure in background.

May 5, 2010 roofing arrives. Completed roof structure in background.

Metal facia being installed. 5-7-10

Metal facia being installed. 5-7-10

Installing the gutter 5-8-10

Installing the gutter 5-8-10

Insulation.   Metal roofs are notorious for turning your attic space into an oven. It’s fairly common to install a thin foil-faced foam insulation under the roofing to try to reduce heat transfer.  We were dubious about the durability of foam under such extremely hot conditions.  We also wondered if so much foam could be a fire hazard so we decided to use foil-faced 25mm fiberglass instead.

Insulation as it comes from the supplier, Far Eastern Hardware, Iloilo

Gluing foil to unfaced fiberglass insulation using contact cement

Foil-faced fiberglass insulation ready for installation

Insulation supported by 16 AWG galvanized wire

The insulation, foil face up,  is supported by a network of 16 gauge galvanized “tie” wire.  Holes are drilled in the purlins and the tie wire in threaded through the purlins.  The holes are positioned so as to leave a 1/2″ air space between the foil and the underside of the roofing.  This spacing improves the reflective properties of the foil.

Followup.  Having lived in the house for four years, we have found another big advantage to the insulation is that the roof is MUCH quieter when it rains.  A neighbor has a very similar house with metal roofing and Hardiflex ceilings but no insulation.  It is much noisier when it rains.  It’s possible that thinner gauge roofing is also noisier. This makes a big difference, especially sleeping on stormy nights. 

The roofing is available in a range of colors.  We’re using a light color.  See this New York Times article on how white roofs save energy.  Dark metal roof colors are quite popular in the Philippines, we guess because they give the look of clay tile roofs.

Roof going on. Reflective foil under roof.

Roof going on. Reflective foil under roof.

Roof going on over foil and fiberglass

Roof going on over foil and fiberglass

Fiberglass insulation.

Fiberglass insulation.

Now that the roof is on, the house looks a bit like a Philippine basketball court.  The interior walls are 3.4 meters above the finished floor.  It’s another 3.0 meters to the roof peak.  The total height is about 20 feet.  We could have spectacular cathedral ceilings, but will likely install ceilings between 3.2 and 3.4 meters above the finish floor level giving us a 10 foot ceiling height.  Even then, changing light bulbs and cleaning ceiling fans will require a high ladder!  The ceilings will be supported by ceiling joists of 1.5″ x 1.5″ 2mm angle bar.

This photo also shows electrical conduit running from outlets to the panel box.  The concrete floor will be poured over the conduit.

The design of our roof includes two large vents high in the roof.   More on that later.

Soffits.  Soffits are one of the parts (along with gutters) of the Philippine house that tend to deteriorate quickly and to require the most maintenance.  Perhaps that is because some use cheap plywood or because cement board does not hold up well in that location.  Maybe it’s because soffits never see the sun and may be vulnerable to mildew and rot.  Whatever the problem, choosing the right material is going to make your life easier in the future.  We have a modest single story house.  Scrubbing ours down is a pretty big job.  If you have a two-story house, maintaining the soffits (and gutters) is a really big job, probably requiring bamboo scaffolding.

Material options for the soffits include pre-painted, ventilated steel soffit packages, plastic ventilated soffits material, Hardiflex brand cement board and plywood.  Since we were trying to give our house a bit of a traditional feel, the metal soffit system, while very practical, are a little too reminiscent of a mobile home for us.   Hardiflex appears to be similar to the asbestos-cement board we used to see, but the asbestos has been replaced with wood fiber.  We decided to use painted 1/2″ marine plywood.  The plywood is referred to “11mm plywood” but actually measures 10mm.  Since a hole punched in the soffit can open up access to the building, we felt that plywood was a more secure choice than the brittle Hardiflex.  The plywood is attached to the steel soffit frame with 3/16″ blind rivets.  The rivet heads are recessed and filled.  All surfaces of the plywood are primed before installation.

Plywood soffit panels August 2, 2010

Plywood soffit panels August 2, 2010

Note that, except for the plywood soffits,  not one bit wood is used in the entire roof structure.  Termites are a part of this, but Philippine forests have been almost entirely cut off and wood is quite expensive.

soffit_vents_long soffit_vents_corner

The finished soffits with vents.  The long vents are available for purchase at building supply stores.  We built the square vents at each corner of the house ourselves.  All vents are screened from above.  These look nice but may be a maintenance headache long term compared with metal or plastic ventilated soffits.

Our choice of plywood for the soffits was probably not a good one.  While we have not had serious problems during the first three years, our soffits get dark with mildew quite quickly.  We have to scrub them down with soap and bleach at least once per year.  Over time, we may have problems with termites or other wood borers.  Look at the metal and plastic options.  We don’t like the look of them, but if you do, they may be a good choice.

lucban_soffit

You can get creative.  This is a soffit with decorative ventilation on an old building in Lucban, Quezon Province.  It looks like sheet metal to us.  Good quality sheet metal (such as Galvalume)  riveted to the soffit frame should be a good choice.  This kind of decorative metalwork would be prohibitively expensive in the developed world, but in the Philippines you find skilled metal workers to do such work for an affordable price.

Cost. The surface area of our roof  is about 300 square meters.  The total cost of the roof excluding the structural elements but including insulation and installation is about P280,000 or about P700 per square meter.  The fiberglass insulation added about P50,000.  We were told to expect to pay about P500 per square foot for our roof but using better materials drove the price higher.  We have not yet calculated the total cost of the roof structure plus roofing but it must be at least P800,000.

We purchased the roofing from and it was installed by Far Eastern Hardware, 38 Quezon Street, in Iloilo City. We dealt with Victoria “Baby” Ang.   When our plans were found not to be complete enough for our crew to build the roof structure, Baby sent an engineer out to help at no charge.   Land line phone for Far Eastern is +63-33-337-2654.  Mobile for Ms. Ang is+63-918-888-2228.  Getting through can be a challenge.  Ms. Ang is quite business-like.  One time she failed to give us the usual friendly greeting to us as we walked in to negotiate an order for more building materials.  She joked, “if you want friendly, go to Jolibee” and laughed. Our business dealings with Far Eastern and Mrs. Ang were always straightforward and satisfactory.

Far Eastern Hardware on Quezon Street. Iloilo City

Far Eastern Hardware on Quezon Street. Iloilo City

 

 

 

 

 

 

 

 

 

 

 

 

far_eastern_contact_info

Summary. All parts of this Philippine roofing system are matching;  preformed and pre-painted so that the entire ensemble of roof panel, gutter, facia board and ridge cap are in the same design and color.  This is a very slick, economical and attractive system which provides a durable roof able to withstand the monsoons, typhoons, termites and other rigors of life in the Philippines at a moderate cost. We’re impressed.  My only reservation is that roof sealants (Elastaseal, Vulcoseal etc.) seem to be an accepted part of the Philippine roofing world.  I have some experience with high quality metal roofing on U.S. historic restoration projects.  I consider the use of these sealants to be a bad sign.  These sealants always fail.  A roofing system that depends on them is poorly designed and will require frequent maintenance as the sealants break down.  Our rental apartment has a metal roof.  Whenever there’s a strong rain, it leaks and the landlord sends a crew with tubes of roof cement to try to repair the leaks.  That’s not how I’d like to spend my retirement! A properly constructed metal roof will use proper design, not sealants and will be leak free for decades.

Roof completed 5-20-10

Roof completed 5-20-10

2016 Roofing Update and Reality Check

The previous paragraph, written six years ago turns out to be a little optimistic.   We like to keep our readers updated on how things are holding up, be they good or not so good.  We have been living in our house for almost six years.  The roofing and gutters have generally held up well.  We see little corrosion of the roofing on the house.  That is because the underside of the roofing is protected from moisture.  This not been true of the same roofing material used on our garage.  The underside of the garage roofing, the purlins and the “tek” screws have been exposed to wet typhoon winds and have corroded with alarming speed.  So, durability of the Philippine roofing system seems dependant on it being a closed system, not open to the elements as it it with our garage.  While this has not been a problem on our house roof.  But there have been two problems.  The heads of the “tek” screws which attached the roofing to the purlins are rusting.  The rust causes stains on the roofing.  We were told we should wire brush the heads and repaint them.  We are doing that, but it’s a big job.  If you can find and afford them, stainless steel screws would be far better.  We have to keep in mind that this common Philippine roofing system is designed for economy.  There are much better metal roofing systems which have no exposed screws.

Roof corrosion in open garage.

Roof corrosion in open garage.

The other problem we have had with our house roof is corrosion where the downspouts connect to the gutters.  The roofers cut a hole in the bottom of the gutter and fashion a spout which fits into the top of the downspout out of the steel roofing material.  The blackish material you see in the photo below is epoxy paint to try to reduce the corrosion.  The epoxy paint will be touched up with paint matching the gutter.

Of course keeping gutters clear of leaves and other debris is another constant task.  Whenever we have a heavy rain we run around the house to make sure there are no clogged downspouts.  If a downspout is clogged the water will overflow the gutter.

See also your problems with catch basins settling and disconnecting downspouts at Beware of clay soils in Philippine construction.

Gutter, downspout connection

Gutter, downspout connection

 

 

 

 

 

 

 

 

 

 

Roof Design

Here’s a little about the architectural design of our roof.   Our roof design goes against the trend.  Increasingly elaborate roof designs are very popular, especially for houses that are or aspire to be “upscale”.  The more valleys, ridges, dormers and other complications the more impressive the house.  Bob was brought up in the northern U.S. where every valley was another spot for ice and snow to build up and cause ice dams and leaks to form,  so simple roofs are an instinctive choice.

These over-complex roofs are a recent development in the Philippines.  Traditional Philippines houses had “dos aguas” or “quatro aguas” roofs.  These terms are a carryover from the Spanish “un tejado de dos aguas”, a simple ridged roof or “un tejado de quatro aguas” a hip roof.  The older members of my construction crew still understand and use these old Spanish terms.

Simple gable roof

Simple gable roof


Hip roof

Hip Roof

The hip roof has been very popular in traditional Philippine buildings and for good reason.  In a land where buildings are buffeted by typhoons every year, the hip roof is streamlined, giving the winds little purchase.

Hipped roof Philippine house

The roof above was popular in the 19th century but during the Commonwealth era one starts to see a modification which adds roof vents.

Here's an example south of Cebu City

Here’s an example south of Cebu City

Closer is the old Guimbal, Iloilo Municipal building. Guimbal has a new city hall but thankfully has preserved the older one.

Closer is the old Guimbal, Iloilo Municipal building. Guimbal has a new city hall but thankfully has preserved the very elegant older one. Photo from HCS.

House in Lucban, Quezon Province

House in Lucban, Quezon Province, our architectural model.

In Western architectural lingo such roofs are called “gablet” roofs or “Dutch gable” roofs.

gablet_roof

Certainly the aesthetic for this roof  is inspired by the roof profile of the beloved Philippine “bahay kubo” native bamboo house. Filipinos, rich or poor, seem to have a deep attachment to life in the provinces.  For Filipinos, the provincial life  and the bahay kubo conjure up an idyllic paradise lost.  Of course Filipinos know about the hardships of provincial life, but those don’t seem to dilute the romantic attraction of life in the provinces.  Just consider the current crop of TV soaps which alternate between a sorid, squabbling life in huge, pretentious houses in Manila, lives filled with greed, envy and bickering.  Then in a flash you are in the provinces, in a bahay kubo,maybe with some pretty capiz windows–a harmonious pastoral life populated with kindly, wise lolos and lolas with birds singing and maybe a carabao contentedly ploughing in the background!

Panay Island bahay kubo

Panay Island bahay kubo

This rustic bahay kubo roof design, transferred to wood frame and concrete buildings,  has evolved to incorporate a ventilator in the peak of the roof.  We wanted to incorporate at least some Filipino style into our house and also realized the advantages of attic ventilation under our hot metal roof.  Here’s our original design for a two story house.

Perspective Drawing for our Tigbauan House

Perspective Drawing for our Tigbauan House

We finally decided on a one story home but kept the roof design we liked so much.  In retrospect (5-12) this was probably not a good decision for our very exposed location.  Storms blow water through the ventilators onto the Hardiflex so we have had to block off the ventilators.  Readers have recommended that we install storm-proof ventilator grills.  We shall do so but our attic ventilation is adequate without the vents at the peak.  Including the peak vents added complexity to the construction, cost quite a lot of extra money, will require maintenance and really provide little or no benefit.  The low pitched hip roofs seen on many Philippine houses are practical and affordable.

Workers install Mahogany ventilator in roof peak of our new home

Workers install Mahogany ventilator in roof peak of our new home

More at /our-house-project-design-devolution/

Comments (158) Write a comment

  1. Hello John,
    How did the house turn out? Would like to see it sometime. Ana and I are hoping that you had no damage or injuries from Typhoon Yolanda? We currently live in Quezon City (Metro Manila). We are moving down to Sagay City, Negros Occidental, as soon as our new house there is finished. Decided to build one for us and not for everyone else for a change…lol.. If you get time drop me a note at (amc_renault@yahoo.com), or SKYPE (Arthur.Netteler).

    Reply

  2. I have been roofing in Australia for 13 years and I have seen your photos and it seems to me that you are installing the insulation wrong
    Over here we install the insulation foil facing down on the mesh
    Because over time if u install insulation your way the fiberglass will be cut by the wire mesh by expantion and contraction of the metal and will fall through the mesh onto your ceiling
    And of course I love your bamboo scaffold
    Another question is can your workers walk on the roof?

    Reply

    • Kris,

      Thanks for your comment. We installed the foil/fiberglass the way we did because we we told the reflective foils should be underneath the roof so that it can reflect incoming heat back from the roofing. I do not know how that would work reflecting radiant heat back through the fiberglas?

      So far (three+ years) we have not seen a problem with the wires cutting the insulation or even much of any sagging. Of course three years is not so long. Check back in ten years and we’ll give a report.

      We did use the heaviest .6mm roofing material. It can be walked on without denting. Also the .6mm gutters are not damaged by ladders. The .6mm is definitely worthwhile. Of course we don’t encourage anyone to get on the roof and do anything — especially drill any holes!

      Bob and Carol

      Reply

    • @ Kris Cook… I am a retired (40yo) Commercial Contractor from the USA. Our Company has been using the foil backed fiberglass insulation for 35 years. In this application it is installed correctly. In HOT/wet climates it is proper to install the vapor barrier to the outside. This has 2 reasons. First to reflect as much radiant heat outward as possible, and also to allow any seepage of water to run off harmlessly to the perimeter of the building. In cold/dry climates it is best to install the vapor barrier toward the inside. This also does the reverse. Reflect as much heat as possible back into the structure, and also to prevent valuable humidity from escaping to the outside atmosphere. By the way… My Filipino wife Analiza and I moved to the Philippines back in June 2009. I have been building single family homes here since we moved. We currently have projects on Negros Occidental Island.
      Please Pray for the people that have been devastated by the Typhoon Yolanda.
      Arthur & Analiza Netteler
      Quezon City, PI

      Reply

  3. Hi there, you have a very informative blog and it’s a good read foe everyone who are planning to build their house a’la bahay na bato. What caught my attention is the decorative ventilation and canopy design. Can you please recommend someone who can make this around Manila? Thanks..

    Reply

  4. Good day. I don’t have any knowledge about the cost per sqm for the roofing, including the perlins, and the fundation for the roofing. I’m planning to renovate our roof and the estimate measurement of the surface area is around 90sqm. I don’t really have any clue since I do have only a maximum of 300k flat budget just to renovate our roofing and I’m planning to do this by summer next year. Thanks!

    Reply

    • Mark,

      There so so many variable that it’s really hard to give you worthwhile advice except that we paid P700 per square meter for our roofing job. That was roofing materials and labor. Purlins are not included. They cost about P400 each. Our roofing was heavy material. Regular roofing would be cheaper and very basic galvanized roofing cheaper still. Sorry to say, that’s about the best we can do for you.

      Good luck with your project.

      Bob and Carol

      Reply

  5. EDIT – We received the below comments. We have no experience with this firm so we are posting the comment without a recommendation, one way or the other. Bob and Carol.
    for roofing need please call us or visit our office Crossworlds Trading and eng’g services @ door 3 zerrudo complex (former lopez arcade) e lopez street jaro iloilo city. with tel. number (033)320-0681 mobile no. 0932-8771-833. we sell and install high end roofing materials only. clay tile from japan,europ & german. asphalt shingles from GAF of USA. Other product such aluminum cladding, insulation, solar panel, outside ceiling, etc.

    Reply

  6. Hi, can you recommend somebody who does roofing repairs here in iloilo cIty? We just arrived from canada and im really in such a lost finding good people for the job .thanks

    Reply

    • Gina,

      As we built a new house we don’t have too much experience with roof repairs. Far Eastern Hardware on Quezon St. did a great job for us. We did watch roof repairs on our rented apartment. These involved smearing Vulcaseal (a tar-like materials) on the suspected leaks. It’s a terrible way to fix a roof. The underlying problem needs to be found and fixed, not plastered over with roofing cement. It may well be that the roof was never properly installed in the first place, or poor materials were used. Anyway, if you need a new roof talk to Baby Ong at Far Eastern.

      Good luck!

      Bob and Carol

      Reply

  7. Bob,

    You said that you now feel the “low-pitched hip roof” is more practical vs. the Dutch gable.

    Would corner soffit vents, such as yours, be sufficient or do you think that a continuous soffit vent should be installed on all four sides?

    In regards to attic ventilation on a hip roof, are there any concerns about heat build-up at the ridge or peak (depending on design)?

    Thank you.

    Ted

    Reply

    • I sort of wish we had done the lower, hip roof because our roof peak vents (which cost quite a bit to build and added complexity to the roof) are blocked off and don’t do anything. We do have soffit vents and I really have not seen a problem with the blocked off vents. If you have insulation above the ceiling and if you have soffit vents, I feel you’d have a good, economical, weatherproof (rain + wind) roof. After all, that what thousands of Filipinos have! One thing great about our higher pitch roof is that it’s so easy to work in, such as for wiring, cable etc.

      Bob

      Reply

  8. thank you for this informative blog, i am an architecture student of the University of San Carlos in Cebu and i started young in the construction where i learn most of the things and construction, the roof truss and roof beam connection using re bars is very typical in the construction specially in housing construction in Cebu, but when i look at plans and specification they specified using u-bolts to fasten roof truss to the roof beam, the time i read this blog i was amazed that the connection of the 2 members using re bars has proved to be structurally strong to withstand typhoon, when all i thought before that these method is only used because u-bolts are additional cost in construction… the spacing of the c-purlins and the other connection of other parts of roof makes it more clear to me with the use of the pictures, i would surely recommend this very informative blog to my fellow students. again thank you sir!!

    Reply

    • Rommel,

      Thanks for your kind comments. Glad you have found the blog to be useful. Our engineer and our construction crew felt that securing the trusses to the roof beam by bending over and welding the column rebar stubs to the trusses was a good approach because the rebar is firmly anchored all the way down to the column footers. Engineers have criticised this method, one saying that the trusses should bear on steel pads. I would be curious to hear arguments on this point based on engineering principles or examples where a well-implemented rebar method has failed.

      Bob and Carol

      Reply

  9. Bob Many thanks for your details on your house. Please could you advise how your roof is after three years. My wife and I (well owned by my wife) have a Filipino built house in Arevalo Iloilo which needs a new roof. We have owned this house for about 10 years and guess its was built around 20 years ago. The builder has told us the galvalume would last for 45 years before it needed painting seems a long time for any thing to last in the Philippines. May not get it insulated yet as we have rented it out since we purchase it.

    Regards Daryl

    Reply

    • Daryl,

      45 years! I always get a kick out of people, especially young people making such claims. Our .6mm galvalume roof is holding up very well. There is no sign of rust, even on cut edges. I am afraid that I will not be able to report back in 45 years, but one of the reasons that I chose and spent more money on quality roofing is so that the maintenance problems for my wife will be minimized. I think it will last a good long time.

      Bob and Carol

      Reply

      • Bob Thanks for your reply. Like you I can not believe it will last 45 years and also will not be around to find out. Unless 99 is to much to hope for. I was also recommended the 6mm so looks like that is what I will go for.Great blog you make life for the rest of us a lot easier.
        Daryl

        Reply

    • It’s for insulation, to keep the attic a bit cooler as the sun beats down on the roof.

      Reply

  10. May I know who is your contractor for your house? I am planning to build our house early next year I am canvassing for the best and affordable contractors and materials

    Reply

    • Jefrey,

      We did not have a contractor. We just hired a foreman and a crew and did the purchasing and supervision ourselves.

      Bob and Carol

      Reply

  11. Eric, we are in the process of bringing Energy Shield Paint Additive to the Philippines. In applications in India & the Middle East we have realized a difference of 18 degrees Celsius between the roofing covered with our product & roofing not covered. Inside the building there was a difference of 5 degrees Celsius.
    Geoscience Labs in the USA in their testing found a savings of 42% in energy using our product.
    Basically these are special glass spheres at 15 microns, the SRI is 112~114, you can just add it to any paint you wish to use, it can be applied by brush, roller or spray. Good for steel, concrete or wood.
    If you would like more information, please contact me at kevinmcnamara@converdegroup.com

    Reply

  12. Hi Bob,

    I am building a house in batangas, right by the sea. I am also using a metal roof, most likely dn steel because they have the 45/55 zinc/alum coating. I am trying to figure out insulation.

    How has the fibreglass been so far? Is that the same as rockwool?

    I am using wooden trusses, galvanized perlins spaced at 0.6 meters. My architect is recommending a foil barrier, then marine plywood under the steel sheet but the guys on the cebu forums say that the plywood won’t last due to the heat (i tend to agree based on several asphalt shingle roofs I’ve seen here).

    Anyway, would appreciate an update on how the fiberglass has been so far? I read that mice like it? I had a roof in our old house which had mice and it was annoying.

    So, am thinking of a foil/fabric type reflective barrier, then 2 layers of 2 inch white styrofoam. Then close off with marine plywood.

    I hope phils is treating you well.

    Thanks!

    Eric

    Reply

    • Eric,

      Yes, I believe rock wool and fiberglass are similar. We have only very minor problems with the fiberglass so far. There are some places where birds or bats can squeeze into our attic. These need to be fixed. The birds disturb the fiberglass. but just in a tiny area. 99.9% remains undisturbed. I would not go overboard with the insulation. The foil faced foam might be enough. Our concentration on a cool roof helps but it’s far from trans-formative. Shade trees are the real answer. Is the plywood you mention going to be your finished ceiling? I recommend Hardiflex instead. Much of the so-called marine plywood is really lousy. Great that you are using galvanized purlins. And yes, the DN .6mm galvalume is holding up so well. We get some salt breeze at our house during storms. The salt has already eaten holes in the aluminum window screening, but I don’t see a jot of corrosion on the .6mm roofing.

      Bob

      Reply

      • Robert,

        Thanks, I appreciate your reply. Will definitely go with the galvalume. And I take the point on the marine ply also. There is a higher quality marine ply (santa clara brand), but am not sure it will work for the roof.

        I do want to go overboard on insulation. I think the foil + styro shouldn’t be expensive. Styrofoam has some emission apparently, but it might be the lesser evil.

        Our finished ceiling will be hardiflex. But there’s some chance we will clad a portion of it with wood planks. My friend who imports cedar is offering a one time big discount for us.

        Btw, if you have trees near the roof, you have to clean the gutter regularly, maybe 2x a year. Ours rotted after 10 years because of the leaves. Shade definitely helps. For our beach house, I don’t think we have a good location for trees.

        We’re building close to the edge of a (low) cliff. Our location is incredibly salty. During habagat, if here is a strong breeze without rain, sometimes the leaves of all the trees, including some pretty salt tolerant plants, all wither and fall off for two to three blocks around us.

        But, we really like it where we are. Breezy pretty much all year round, nice view, and cheap sea food.

        Best regards

        Eric

        Reply

    • Eric,

      All insulation system in the attic will fail to cool the living areas of the house if there is not enough attic ventilation system. In the Philippines, I’ve seen a lot of houses having sufficient venting on the eaves of the roofs, but nothing on the “upper part” of the roof. We know that warm air “rises” so the hot air is mostly trapped in the upper portion without the “upper venting”. The US building Code, like the International Building Code, usually shows how to compute the required net ventilation areas for both lower and upper venting based on the area of the roof. The reason why there is lower and upper venting is to have sufficient air movement within the attic. Fresh air comes from the lower vents, and exits at the upper vent. In that way, warm air is not trapped inside the attic space and helps cool the temperature inside the house more sufficiently.

      Reply

      • Hector,

        Thank you for your excellent comment. We are having our afternoon storm today. It reminds me that we did build in decent vents in the peaks of our roof, but that our location is so open that wind-driven rain is very strong and very horizontal, so we have kept our peak vents closed with plywood. Otherwise our Hariflex ceilings would certainly would have been destroyed by incoming water.

        Others have commented that we could put in “storm-proof” vent louvers. We have not gotten around to seeing if they can really work in our circumstances.

        Thank again,

        Bob Hammerslag

        Reply

  13. Hi,

    I have house near Dumaguete; hilltop overlooking the sea. Typhoon Bopha peeled back the front end of the roof and now I am rebuilding the roof to stronger construction.

    I have a quote for 1MPesos and not actually sure how reasonable that is. Total roof is to be replaced covering total area about 250sqm floor area. Roof is long shallow height gabled style.

    Can anyone advise. Construction targetted to be as strong as possible.

    rgds

    Phil

    Reply

    • Phil,

      Would like to be able to help but there are so many variables that we can’t say anything helpful except that our roofing and insulation cost about P700 per square meter in 2010. That does not include any structural work such as purlins, rafters etc.

      Good luck,

      Bob

      Reply

    • I think 1million pesos for your roofing is too expensive, try to visit hardware stores yourself to get the right qoutation. Labor should not exceed 100k. I am also building a house in negros.

      Reply

      • Jareal,

        As I said in our post we paid P280,000 for the roofing. We got three quotes on the roofing job and took the lowest priced one.

        Bob

        Reply

  14. Looking at the foil+fiberglass insulation. Doesn’t placing the foil right next to the sheet metal defeat the purpose?

    Insulation is about “airspace”, so the density of the fibermat provides the airspace. Aluminum foil is supposed to be a heat barrier like in spacecrafts. So is it not supposed to stop the residual heat getting through the fibermat?

    I read somewhere that what makes foil great is that captures heat very well and dissipates it. Unlike styrofoam that will store the heat during the day and then release it at night when the temperature difference between the foam and ambient reverses. That is why electronics use aluminum as heat sinks.

    If you trap the foil between the sheet roof and the fibermat, how can it dissipate the heat?

    Reply

    • Mark,

      Thanks for your comment. Our foil is not immediately under the roofing. We read that there should be at least 25mm between the underside of the roofing and the reflective foil. We did provide for that in placing the grid of wires supporting the insulation. We also read that the reflective should be above the fiberglass insulation. See http://www.yourhome.gov.au/technical/fs48.html. Perhaps in a cold climate you want the foil inside to keep heat from escaping and in warm climate have it outside to keep the heat out?

      Bob

      Reply

  15. I really love the work you have done here. Has anybody looked into prefab construction metohds and is it any less expensive and of quality

    Reply

  16. Elle,

    I’ve had quite a few inquiries about the fiberglass insulation so I added some more photos and information to the roofing section http://myphilippinelife.com/our-philippine-house-project-roof-and-roofing/

    I guess I should create a new section just on insulation.

    Far Eastern did supply the fiberglass insulation and the foil. In fact I just bought more of the insulation from Far Eastern (Baby Ong 0918-888-2228) to use in the ceilings of our air conditioned bedrooms — in addition to the insulation in the roof. An engineer, who is a reader of the blog, estimated that insulating by bedroom ceiling would save 10% in electricity consumption. I am not sure if you can buy the insulation with foil aleady attached but I can report that gluing the foil to the fiberglass batts was quite fast — not a problem.

    I offer a little more food for thought. The thin foil-faced foam insulation that is usually used in roofs may be less bother. It’s quite easy for all the creatures (rodents, birds, lizards, bugs) can burrow in the fiberglass batts. This happens to batt insulation in the USA too. Mice chew it, nest in it and so forth. This does not necessarily reduce the insulating value, but can be discouraging and unsanitary. So the fiberglass is much more effective, but more expensive and fragile than the foam. Likewise, it’s unclear how durable the foam really is. It’s exposed to very high temperatures year after year.

    Finally, keep in mind that roof insulation is just one small but important part of the cool building effort, not the whole story. Some our our trees are big enough now to shade the roof and yard. That helps more than any insulation!

    Good luck.

    Bob

    Reply

  17. what kind of metal did you use for the fascia? could you give me the thickness and other details, as i will try to repair the gutter system in our house. thank you

    Reply

    • The fascia is the same .6mm (gauge #24) thick as the roofing itself. The material is Colorlume from DN Steel. More info at http://www.dnsteel.com/colorlume.html It’s been on two years now and we see no sign of corrosion despite the fact that we get salt spray during big storms from the SW. Amazing, since we are one kilometer from the ocean.

      Reply

  18. Onduline is a lightweight, tough aspahlt corrugated roofing material that can resist corrosion, heat and sound insulated properties, non asbestos. this is an ideal roofing especially in a tropical country like the Philippines which is surrounded by the sea.

    Reply

  19. Bob and Carol,
    Why did you not put another layer of insulation above the ceiling to help keep the living areas cooler? I noticed you said that you had to board up the ventilation on the sides due to the rain, if it is not too hard to access the attic would it be better to have someone open and close a crawl space style vent with rubber attached at the bottom to help vent out heat and mositure while being closable for rainy days?

    Zac

    Reply

    • Hi Zac,

      We are putting in insulation above the two rooms we air condition — 25mm unfaced fiberglass bats. We had some insulation left over from from the roof. We put that down and have ordered 30 meters of 24″ insulation to finish the job in our master bedroom, the room that get air conditioned the most. For your information, that insulation costs P2,400 in total from Far Eastern Hardware in Iloilo City. We are a little worried that the insulation will make it harder to keep our attic clean. The insulation is a great place for various creatures to play and hide.

      Regarding the ventilation, the best solution would be some sort of mechanized way of opening and closing the vents. It’s a bit tricky because the storm direction can vary unpredictably and we are in a very exposed location. A mistake could cause lots of damage to our Hardiflex ceilings, even more so with insulation in the attic. Since we have other ventilators and since the attic seems pretty well ventilated without the vents at the peaks, it’s just not a high priority. To be honest, if I was doing it over I’d skip the peak vents and just have a hip roof with lots of soffit vents.

      Bob

      Reply

  20. hello thank you so much for the great pics and information i am a contractor in florida and i am going to be building in liloan cebu a traditional florida style home 3000 sqft 10 ft walls and i want vaulted ceilings in all my common areas and 10 ft tray ceilings in bedrooms i feel it makes it more economical to cool and i prefer the look
    my question is how would i hang my drywall on metal (steel trusses) any sugestions
    would i have to attactch wood to the bottom of these trusses also i see there not 24inches on center they seem to be a larger span because there steel i would appreciate any help you can give me thank you randy

    Reply

  21. This is a wealth of information you provided for all of us to use. Thank you.

    I was looking on the internet for the spacing of Purlins they use for sheet metal roofs as I have not designed homes using sheet metal roofs. All roofs in California, where I was from, have 1/2 plywood under layment and normally wood purlins. I will be designing a triangular steel roof truss using 2″ angles.

    I am in the process of designing a two story house using 4″ block (made by us), concrete columns and a steel framed roof support/sheet metal roof, with second floor of concrete.

    I am from the USA and a Prof. Civil Engineer in California, retired to the Philippines and I cannot believe how they build over here with earthquakes like California. I have not had a chance to read all the comments and yours. Sounds interesting.

    If anybody has this information on purlin spacing, I would appreciate the info. I can size the purlins as long as I know the spacing on a sheet metal roofing. Also your purlins look like 2″x 4″, not 2″ by 3″ ??? in the photos.

    Ed. Velarde

    Reply

    • Ed,

      Our purlins are 2″ x 3″ — I just double-checked. The purlins are spaced 60cm OC. You have to be so careful in purchasing purlins (and all other steel) and inspecting them on delivery. The stated thickness of the material has to be checked and double-checked. We ordered 1.2mm and ended up with something less.

      Best wishes,

      Bob

      Reply

  22. In regards to foil-faced 25mm fiberglass that you used in your home, is it possible to furnish me with a close-up picture of this material to my email address? The picture on your website shows the underside of the fiberglass bats, but I’ve never seen anything like this in the U.S. We are going to be building our retirement home outside of Ozamiz City, Mindanao and would like to use the same kind of material that you used. Unsure if there is a hardware store in Ozamiz City that sells this type of material, but as they say, “a picture is worth a thousand words”.

    Thanking you ahead of time.

    Ester & Paul Vollmer

    Reply

  23. Sir,

    I too am having a house built in la Union. The first thing I thought of is how are you going to hang a ceiling from “Rafter Trusses” meant for warehouse?

    I showed the pics to my welder who did my trusses and he agreed. The Rafter trusses they installed are for warehouses or like you stated shade for a basketball court and can easily buckle.

    My welder said what they may do is hang angle bar down from the rafter trusses and attach the ceiling to that which will be plenty of weight for rafter trusses to support and increase the chance of buckling.

    I can send you a pic of my trusses so you can see how mine were done just reply to my email.

    Dino

    Reply

  24. Hello Bob,
    Thank you for the great site. I refer to it quite often as we build our house in Valencia, Negros Oriental. We are starting construction on our roof for the 2nd floor terrace. It looks like your roof is pretty strong so I thought I would make ours similar. Can you tell me the spacing up and down between purlins and spacing between trusses? Our terrace is 38′ long and 8′ wide, we have 3 -10″x10′ columns to support the soffit end of the roof and the other (peak) end will be part of the 3rd floor railing. It must be nice to have your place done! 🙂
    Regards,
    Scott

    Reply

    • Scott,

      Thanks for your kind words. Glad you found the site to be helpful. The purlins are 60cm on center. The rafters are 2.35m on center. Just be sure to carefully check and double check what you’re actually getting when you buy steel. It would be easy to end up with undersized material. Yes, it’s nice to have construction over and be in our house.

      Bob Hammerslag

      Reply

  25. Pingback: An Amazing “How-to-put-up-a-steel-roof” Project « 21st Century Steel

  26. Pingback: An Amazing “How-to-put-up-a-steel-roof” Project « 21st Century Steel

  27. Wow, this is an amazingly detailed account of your roofing escapades! Like you said, it is unfortunate that we do not have more lighter colored roofs to reflect the heat. I hope it’s ok with you for me to link to your website to show others how you’ve done it as the explanations on what materials to use complete with pictures will surely be very helpful.

    Congratulations again on a job well done 🙂

    Reply

    • Colin,

      Our fiberglass batt insulation was supplied by the roofing contractor so we’re not sure about where it came from. I suggest trying Citi Hardware if you have a branch nearby.

      Bob and Carol

      Reply

  28. Hi Bob!!!

    I really appreciate your post and congratulate you for successfully completed your house structure. I just have some points to share here that might be helpful to the readers and maybe to you as well. First I haven’t seen your foundations (Footing and Tie beams including the soil how it was excavated ), which is the most important in designing an “earthquake proof” structure. Hope the Engineer considered that but if it was designed to be a 2 storey house, then you’re in. Next to consider is the Strength of steel, it should be according to ASTM. Engineering wise it is cheaper to calculate a suitable or accurate size and strength of steel to be used. It’s not only according to the size of the steel but you have to consider the number of these to make it flexible.Well u’r columns is still with the standard, though a little bit expensive.But, for the roofing, i’m glad you had enough money spent on it..steel structure is really over designed or rather i should say over weighed that made ur “earthquake proof” designed house lost. You got a rain catching roof also that will add more weight to the roof not to mention the wind load also. The reason why most of the houses in Phils. are designed into hip roof, is to distribute the rain water. Most are designing a higher slope to minimize the rain water load. For the roof vent that you had i think architecturally wise it is nice I am with you. but you are in an open area and agricultural land. It is useless unless that you have some machines above ceiling it is okay. Your ceiling is also prone to insects because of the vents or else you have to put a wire mesh screen above to protect. You already had a very nice ventilation because of the size and location of your windows which is not covered by the height of your fence and you have roof insulation too. About hollow blocks you used, the most practical size is 5″ or 125mm, Why?. 100mm CHB will cost you much to labors because you have to do it 5 layers at a time, for 150mm CHB you will spend much for the material because the hole is bigger so you have to fill more to it..unlike 125mm which is the cost difference in commercial price is only 1 peso, the hole to fill is same with the 100mm size CHB.

    Anyway, I don’t want to make you feel bad, your house is good enough. I’m into sharing thoughts and info only esp to the readers who wants to build their own house also. If you are going to ask ask an engineer to design for your house make sure that you know him well as an engineer or else you’ll fall into a “contractor”. It is still good to spend more money to build your own home, but it should be worthy and useful. I build my own house too. I am a Civil Engineer too but still I ask a second opinion to my friend which is an Structural Engineer and gather some new designs. You know how much I spent for the structure of my bungalow house with the floor area of 80 sqm? I only spent P295k for structure, block walls and longspan colored metal roofing tile (6 hip) including the labor cost. The price of my house is just one-third the price of your roof.
    We call it “Value Engineering”.

    Best Regards,

    Badger

    Reply

    • Wow!! Really? You gave me hope!! I’ve been working to start constructing the 2nd flr of my house, abt 70sqm (including garage roof) for P300,000 (no finishing/no paint except the bathroom). What about having it constructed using prefabricated, light materials? Do you have any opinion on this? Will really appreciate it. Thanks!!

      Reply

    • Nice to read your comments here. I’m also building a house in the Philippines. Puerto Princesa. I hope to use hard wood rafters and joists, and would like open vaulted ceiling. Any thoughts about this type roof in the Philippines?

      Reply

      • Just a couple of quick thoughts, certainly not intended to discourage you. Perhaps the vaulted ceiling will keep the hot air up, away from occupants. That’s assuming that you don’t plan to air condition the rooms with vaulted ceilings. I assume increasing the volume of the room would increase the cost of installing and running air con. Perhaps good hardwood is more available on Palawan than on Panay. Here, decent stuff is hard to get and expensive. Steel is cheaper. In any case good luck!

        Reply

  29. wow !!!! this is really a helpful site …. i was just trying to search if it is safe to use hardiflex for ceiling … knowing that in Philippines, it is difficult to trust “them” that sells or criterias like original, semi-original, or maybe made in China are least expensive, next Taiwan etc… but my only concern is, If i use hardiflex for my ceiling, am i sure that the hardiflex being sold in Iloilo are the ones that does not contain ASBESTOS ? regardless which country it came from, manufacturer or price, are there different kinds of hardiflex, that can be use on a ceiling ?

    Your site is really amazing, recommended it to my friends as well who are in the process of building a house in Philippines, just like me…. and I happened to build a house in Tiwi, Barotac Nuevo, there in Iloilo. So do you think it is best to use hardiflex for ceilings ? And is it possible to design a ceiling using a hardiflex ? Thank you so much and mor epower to you..

    Reply

  30. Hello Bob,

    Outstanding post and very helpful for my education of much needed knowledge of a wide variety of subjects.

    I am living in between Iloilo and Barotac Nuevo, a new comer to the Phils with a family here. I have recently constructed a wall and concrete post fence with the cheap inadequate cyclone wire that is only to be found on this island so next year I will remove the cheap wire and install all metal fencing.

    I have found workers like to use too wet a mixture and I don’t think they realize the consequences of their actions in the future. A couple of pre existing columns were torn down because they were so soft you could push the sand out of the steel rebar inside. Apparently due to some previous poorly made concrete mix decisions from workers 5 years ago.

    I passed up the opportunity to buy the 70 4 inch blocks per bag of cement sold locally for the 50 or 60 blocks per bag sold in another town. I could break the weak blocks by hand. Unless I invest in a block forming machine I am stuck with the weak blocks but it is just a fence wall just half a meter out of the ground and half a meter down.

    I will never hire the crew I now have. The leader is away all day and I have to try to get them to understand English and how I want things done. Luckily I have bartered for a price per length and only pay in percentages of job completed.

    I will have to rework all of my metal work because the workers are not well trained but I really am not complaining as I am getting a great price for the labor of digging the trenches and building the columns and concrete mixing so I am putting up with the poor quality. If this were an important structure I would be much more strict. I am a metal craftsman so I’d rather do the metal work myself anyway. One of my gates looks like a third grader put it together with some play doh and I will definitely be tearing out the pieces and re working the gate myself in the future. It was worth it for me to see what kind of quality worker I had on the gate anyway. He won’t be in my plans for any future work.

    My columns which are about 7 feet off the ground were poured in two parts. One part up to the top of the blocks and then later the top part. With all the steel embedded in them I really did not care although I thought it should have been one pour. Some worker cut the boards by mistake in the beginning of the job so instead of having me buy another board they just poured the whole 45 posts with two pours. It’s not proper but it won’t go anywhere with the strength of the mix and all the steel inside.

    What is it with all of the places I go to buy steel at? I measure four pieces of flat bar and the total thickness of all four is half an inch. But they tell me it is charged at 1/4″ thickness each. I explain to them that then it should equal to one inch with four pieces but all of the places say that it is done at the main distributor at the import yard. They are labeled as thicker than they are. Except for the sheet metal and some rebar. But pipe and other stock is sold as thicker than they are. I’ll continue to shop around until I find some supply place that sells it properly.

    Our home is basically a one meter high wall foundation with wood framed top and metal roof. It is anchored by tie bars and survived the last earthquake within the last 5 years. I don’t know exactly when it was but the house is 5 years old. I like the flexibility of the wood top and the strength of the foundation. It’s small enough that if it should ever be ruined it won’t cost much to resurrect.

    After this group of workers leave I’ll be looking for a more qualified group who can help me with my projects after a year’s time. I’m tired of lending my tools. You’d think that if you were working for a customer that you would have more than a hammer and half a worn out shovel and wire cutters that can’t cut a skewer stick in half. I’ve already given them new tape measures because theirs were so rusted and worn I felt sorry for them but they don’t bring them to work. So I am hoping the job is finished soon.

    Glad to have found this site and will be reading lots of it. I am going back to the states as soon as I can get my wife a visa to come with me and sell my stuff there and work a few more years. I’ll be back and forth over the months, planning to stay twice a year for a month each. Then permanently retire here later. Thanks for a great article and pictures of your work. Looks really strong and safe.

    Reply

    • George,

      Thanks for your account. It all sounds like the usual travails of construction in the provinces — bad block, bad concrete and all the rest.

      I was so frustrated when I had to buy cyclone wire in Iloilo. I went everywhere and all I could find was the poorest stuff. I had a cyclone wire chart from a Chinese manufacturer. They made lots of good quality fencing but everyone here wants the cheapest. I was willing to pay, but good fencing was just not available. Probably you have to go to Manila to get better stuff. If I was doing it over again, I’d consider starting out with two weeks in Manila, shopping, and loading a container with construction supplies — plumbing fixtures, fencing, better stock and hinges for making my casement windows, ceiling fans, appliances etc etc. Maybe I’d buy a container in Manila, fill and ship it here and use it for secure storage during construction.

      Regarding steel, one of the first things I bought was a caliper to accurately measure and compare steel. It’s a jungle out there! It was a great and even entertaining purchase. I had the best luck buying steel from Far Eastern Hardware on Quezon St. in Iloilo City. I dealt with Baby Ang who sold me the caliper and knew I had it. I enjoyed doing business with Far Eastern.

      Thanks again and good luck.

      Bob and Carol

      Reply

  31. hell bob, im here from manila. Please i need help bout how to calculate the exact price for building roof thruss. Or let say qoutation roofing materials. Kindly do me some knowledge for this. Thanks and God Bless us all

    Reply

    • Daniel

      Wish we could help but these calculations will require an engineer for the design and knowledge of local materials prices.

      Bob and Carol

      Reply

  32. Hi
    well what an interesting read that all was. I shall be building a house in a few years time at the North end of Cebu in Daan Bantayan and have been struggling to decide on what kind of roof to put on. Having seen many steel roofs in construction, I always thought them to be probably very expensive and high maintenance in the end. I would be interested to know what the span of your house is and the length of the trusses as I want to cover about 35 feet or 10 metres in my design. My first choice however was to be an almost flat concrete roof so as I could install a 5M x 3M glass skylight for star gazing !! The size of the concrete roof in total would be 10M x 12M. I then thought that would require huge concrete beams to support the weight and got despondent. Next idea a traditional timber frame Hip roof with coogan grass. I know that requires maintenance but is aesthetically pleasing.
    After reading all the great ideas and input and seeing there are a few engineers participating, I would welcome any idea on the best way to cover the area as stated.
    Thanks for a very interesting read

    Dave (currently in the UK)

    Reply

  33. Pingback: Our House Project – Steel and Welding | My Philippine Life

  34. Pingback: Building our Philippine House – Index | My Philippine Life

  35. Pingback: Roof and Roofing Post Updated | My Philippine Life

  36. We should keep the tradition of Bahay Na Bato without that spanish garbage and be more like our neighbors in Asia, we’re not spanish we’re Asian!.

    Reply

    • yah its true,,we filipino should adapt the heritage of being asain, we are divided into continents,we belong to asia and spanish are belong to europe,,these gives us an idea on how to advocate the beauty and treasure of our buildings and houses

      Reply

  37. This question is about roof ventilation. You said that you were planning soffit ventilation to assist in cooling your house. I have seen the front elevation of your house that shows the completed soffit and in the photo above it shows the installation of plywood soffit panels, but I see no evidence of vents. Have you changed your mind about soffit vents or are you using a different method to vent the roof?

    Reply

  38. Pingback: Our Philippine House Project – Roof and Roofing | Philippines or Bust

  39. Hi,

    I’m being directed to this site by a friend just to give my comments. I’m a civil engineer here in Cebu. I haven’t been to other countries, so my ideas are just confined on Philippine setting, with regards to methods of construction. I also want to say at this point, that, mostly filipino engrs are not fluent in speaking and writing, so, my apologies…

    During my younger years, in the later 80’s, I had been working on a non-conventional house projects in Manila. We did the so called “Panel Systems” where we used two faces of welded mesh wires with sandwiched Styrofoam in the middle. Sandblast mortar on both sides were made just to increase strength of the panel. The same material is being used for roofs, walls and suspended floors.

    In terms of rigidity and strength, our standard or conventional form of construction with columns and concrete hollow blocks is far stronger than our panels. But our houses for sure, withstood typhoons and earquakes, since, I haven’t heard from the news that said our work was blown away or collapsed. Our objective then, was to construct a low-cost house that is affordable to most Filipinos and requires little time (less than a month) to construct the house. We were doing an engineering job.

    But, why do you have to construct a one-storey house with 30 cm width of concrete post and 1:2:3 design mix? Its preposterous! I agree that our construction is “overkill”.

    I have a friend who just finished construction of his one-storey apartment, and at the start, I suggested to minimize size of columns. He replied that he can’t deviate from the plans because the City Engineer’s office is so strict with the construction.

    I can say Bob’s roofing trusses is good, because, it is an alternative material than wood which that latter is now very costly in the Philippines. But, the downside is that, most of our workers are not good in workmanship, so you will see connections from columns-to-truss is so poorly done. One can notice it in the picture, and this is a common scenario especially in Visayas with regards to that connection. Proper way of doing this is to have a metal plate (about ¼” in thick) welded to the exposed column rebars and later on, apply concrete grout just to seal the welded portion. This metal plate is to give proper seating of the truss, thereby, giving structural soundness. Not just bend the remaining rebars to “hug” on the top chord of the truss. I’m sorry to say, that this is poor workmanship.

    The problem with brick walls or hollow block walls is that, it takes time to plaster and this involves costs. Also, in the Visayas area, there are only few skilled mason workers that can do excellent work in plastering, or else, if you hired a non skilled, you end up a “wavy” walls, Non-skilled workers and reworks are factors affecting cost.

    I don’t know if I got it right, but, I don’t agree that water is an enemy of the concrete. Right amount of water will make concrete to attain its maximum strength. It’s a concept of economics’ diminishing returns. For example, in a normal aggregate condition, it requires a 21 liters of water per bag of cement for a 1:2:3 proportion just to make it in perfect “plastic” state. And for every liter of water is added to what is required, it will diminish its strength by 100 psi. But why do you have to have a 1:2:3 (3000 psi) design mix for just a one storey house? No way, unless, money is not an object of construction.

    I’m not an architect, but I had been looking forward to the day that I can build my house conforming to my own design. So that, I have been doing research for western homes and that of ours. IMHO, I found that western designs are just so very practical and functional and the rooms are well connected to each other. Some Filipino architects design foyers leading to a blank wall because, when you turn 90 degrees to the right is an opening leading to a living room and on the left opens a hall towards a Master’s bedroom. Whilst, American houses directly entries to the living room, or a long hallway that ends up a living/family room because dining room and kitchen is in the front. I prefer the Americans house being designed. Another notable differences is that, Filipinos tend to build a dirty kitchen in addition to the main kitchen an indication that Filipinos are fond in holding parties inside the house. American houses only have one kitchen. Materials are sensible and flexible because, for me, why do you have to build a house to last a millennium, when you live a life 20-30 more years. Why do you have to build a house to last for 100 years when life is fast changing? Hehe.

    I found wooden house to be more flexible than concrete. You can reconfigure you rooms anytime, if you want. But the problem is that, wood is very costly in the Philippines nowadays. For those who are interested to build wooden homes, there is a company now that offers wooden homes called Mattwood. I think their price is competitive compared to the conventional system, otherwise, they don’t exist in the Philippines. Based on latest inquiry, their wood products are imported from Australia and they are offering 25 years warranty. I don’t have any connections to this company or whatsoever, I’m just interested in this type of houses, than concrete.

    Thanks for reading.

    Reply

    • Ronel,

      Thanks for taking the time to make some very useful comments on our house building project. I’ll publish them so that others may learn from them but I’d also like to respond to some of what you say, just to keep the friendly debate going.

      First of all, almost all structural details were developed by the engineer on the project. He was aware that we wanted an earthquake resistant house, built to prevailing seismic standards, so maybe that’s why things were “overdone”. Our design was originally for a two story house. The engineer said that if we were interested in really meeting seismic standards applicable in our area, that we’d have to use 25mm rebar in the columns. All we we spoke to were dumbfounded by this! We were told NO ONE uses 25mm rebar in two story residences. For the foreigner new to earthquake country, all we really could do was to tell the engineer we wanted a design resistant to earthquakes and to build based on his design. That’s what we did. We were influenced by looking at what happened in Haiti where buildings which seemed to have survived intact were surrounded by buildings reduced to rubble. We hoped by building a stronger building, maybe our house could survive a major earthquake. We’ve since learned that flexibility (ductility) rather than strength is the more relevant design criteria, but given that we’re building a conventional concrete and hollow block house, we prefer strong concrete and larger rebar.

      It should be noted that the 30cm columns were 30cm by 20cm, not 30cm square. This proved very handy as we used 6″ (20cm) hollow block for the exterior walls. With the columns and the block being the same thickness, finishing is simplified. The 1-2-3 mortar mix (one part cement, two sand, three gravel) was at my direction. All seem to think it’s overkill.

      The column to truss connections (column rebar wrapped around trusses and welded) were not poor workmanship by our workers, but were as specified by our engineer. We hope that the connection works! It’s a very exposed site in open agricultural land.

      Regarding concrete finishing, I really don’t want perfection. In the U.S. perfectly finished gypsum board is standard. For really,really deluxe homes or historic restorations plaster is used. The imperfections of plaster are desired as opposed to boringly perfect “sheetrock”. My workers seemed really quite skilled at finishing. I watch them work thinking that in the U.S. their “plastering” skills would be so prized. They would make in ten minutes what they make in a day here.

      I do agree with you about house plans. We were considering buying an existing house. It was a big, well-built house at a good price but we hated the plan. The kitchen was cramped. I assume that the owners expected helpers to do the cooking so they didn’t care about having a nice kitchen. The CRs were small and had no ventilation so were pretty unpleasant. The living areas were deluxe. We did not see how we could easily change the plan to accommodate a larger kitchen or CRs. Our own plan is simple and open. We have four bedrooms, two CRs. The rest is an open plan combined kitchen, dining and living room. We have a big lot and consider our porch, future gardens and bahay kubo as part of our “living room”.

      There are sawmills in our rural area offering (aside from coco lumber) mostly Mahogany, Lauaan and Acacia. We never considered building a wooden house — except of course for our bahay kubo. The wood available is nothing like the fabulous tropical hardwoods used to build old Philippine houses. We’ll likely use some Mattwood — possibly for doors and moldings but really there won’t be much wood, just door casings, doors, crown moldings and baseboards.

      Thanks again for your observations.

      Bob Hammerslag

      Tigbauan, Iloilo
      Philippines
      http://

      Reply

    • Hi Ronel,

      I can noticed your expertise!… thanks for sharing your thoughts and ideas. Anyways, I have a question for you. Though you don’t much appreciate the concrete structures, do you have any idea the advantages and the disavantages of the roof top garden houses?… I’m planning to build one in the Philippines and I don’t have any source of information about it from the web.

      Any help is very much appreciated!

      Thanks a lot,

      Ellen

      Reply

  40. The problems with steel roofing seems to be the results of water ingress through the coating causing rust to form. This is no doubt caused by the expansion and contraction of the metal because of the heat.
    How about coating the new roof with one of the new latex based paints that we see in the stores. The coating would screen the metal surface from the sun and any expansion would be absorbed by the latex in the paint. the fixing screws would also be protected from water that eventually passes through the rubber washers and corrodes the steel supports.
    The paint would also reduce the noise during a rainstorm.
    what do you chaps think?
    Peter

    Reply

  41. Hello Bob and Carol,

    Hey, your home is looking good… Great progress since we were there.

    It’s only been two months but seems like longer than that, hope to see both of soon.

    Robin and Laura

    Reply

  42. (note from Bob: normally we would not allow an ad like this but the product does seem worth taking a look at)
    Want to have a Roof with the ff. qualities:

    – corrosion free
    – heat and sound insulation
    – waterproof
    – made from 90% recycled organic fibers (green architecture)
    – flexible, lightweight
    – durable
    – asbestos free
    – safe and ecological

    then visit A.M. Builders Home Depot in Ilo-Ilo City and look

    for………ONDULINE ROOFING SHEETS.

    Reply

  43. From John Thede,

    HI Bob.

    Thanks, i just thought becasue of the “Provokative” issue.

    My mother in law, Pinoy, lives in Lutac, Barangay of Naga, Cebu City. Its up in the hills, and we, my wife and me bought land up there.

    So, flooding,and mud slides are not an issue there, but certainly the Typhoons, even they normally dont get that hard to Cebu island.

    Ok my mother in law. She build a toilot building this year. 180×180 cm of 15 cm concrete block. Her first concrete building. And honestly i love the mountain people, so sweet and naive in the same time. So i dont say anything to it. just, im sure the rood will not stand a typhoon as its flat corrugated thin steel plates, and the mail will for sure be ripped out or through the plates. 😀

    Proportion is sooo out of the way. its like a toilet bunker.s from 2. ww I smile but its ok, she is happy, but cant se the elegance of the huts she normally build of Bamboo and straw.

    She ask us to bulid a small hut there at first and we intend to as the old nippa is really bad now, but she just build a new one beside the one and left it standing. OK so there is space for a 24m2 with a kitchen and dining open porch. My wifes friend, she and hewr husband runs an enigneering company in Cebu, she her self is civil engineer and has just done a large school in Lutac, and there she used the steelframe/gypsum construction so i asked her for her eveluation on my suggestion. Still waiting but she will answer just now she is busy with a project in Mindanao.

    Wet gypsum, we use it for CR rooms here, it is fully recognized to be used this way, Just covered with gals fiber mats and filler/paint. Or even with a double layer 12 mm gypsum on steel frame it is easy and strong to plaster tiles on it and it last. I had one for almost 20 years and never had any leak or else. Question is how the outer surface shall be protected IF ??. That is still the open question for me, but as its is covered with bamboo mats it might be ok becasue its shielded but open to dry.

    OK to your thoughts and practical problems.

    I was working in saudi for 5 years, lived there, had a house there. I was working for Danish Turnkey Dairies as supervisor and Cheif engineer.

    Concrete, we used retarder to delay the cement proces, and we used chrushed ice in the water for mixing. a tank of water, filled with an amount of ice will bevery cold and cool down the sand/stone when mixed. The hardening process need water, but not from the mix. Cover the surface with jute material and keep it wet. That cools a lot, and give moisture to the hardening.

    Retarder gives time to get the concrete vibrated out in all the corners. And, never fill more than 20 – 30 cm before vibrate, then only vibrated short, fill again and vibrated. Your vibrate the water out, it come to the surface, and help next filling to float, but the pores in the concrete isnt large and hollow when the water evaporates

    “Stone nests”, that isnt easy, when conditions isnt well. but even in your warm climate its still possible, but worst fault is to fill too much concrete at the time before vibrate it, and workers tend to do that and the result is these “nests”

    I treid once, it was in Medina in Saudi, to see how much our cooling tower actually could cool the water down. I desalinated it, then ran it without load. Outdor temperature in shadow, above 40 dgC. Water temperature was 21 – 22 dgC. Off casue it higher when there is load on, but the evaporation is very effective to cool with. Saudis use “desertcoolers. The entrance is like a small tunnel of clothes they keep these clothes wet, and because of the tents dome, and the opening in top you will get an upgoing termic, that draw air in through the entrance opening. just like the cooling towers on three mile island.

    Simle and very effictive. The ancient turks had similar technics for buildings.

    Heat absorbtion. HIstory here, from spanish time, and seen in the building style in sout america, the “hacienda” style, where there is a blacony all around the house, keeping the uoter walls in shadow all trhe time is a way to do it, and often a very beautifull way, but expensive as the m2 there is just as costly as the living area m2. Soo a large roof overhang is the same, and give the shadow so the sun dont reach the outer walls and heat them up.

    The roofs. double roof, “Desert roofing”, where there is a distance under the outer roof , and where the construction gives termic upwind, and vintilating the gap and heat away is one way to get rid of the sun ligth rays converted to Infre red rays, and heat under the outer roof. I see many try to insulate under the roof plates, but that is crazy and bad use of Insulation. Better get the heat away where its created. It can be done with a ridge as you often see in Thai traditional building. That is a bit like ancient Turkish traditions as well.

    With your 1,4 meter overhang its really fine. the hottest periode of the year the sun will never reach your outer walls in the time where its burning hot.

    You will get most your heat from roof, but a ventialtion under the roof will get rid of that. So dont close too much under the roof overhang.

    You couold make the ridge open so that it was a natural ventilation from under the roof overhang and up to the ridge.

    You are fuly right about the concrete bocks and local material. But i wonder why there is so little progress in materials there.

    Like AAC stones, they are made of, sand, cement, and aluminium powder as the “yeast”. That makes it raise to 4 time the size, and makes a lot of bubles as in a bread. The mix is poured in a form, can be (HxWxL) 2x2x4 meter.only filled half a meter, and the mix is then raising to 2 meter. Blocks are made by sawing the big block with steel wires. The rest the process can be done in different ways depend on how fancy you want the stone to be. But it need hardening. Wich is normally done with steam as that is quick and gives the moisture to the cement hardening process. Autoclaving is mainly to dry them out again as it can take time else. Gypsum is the same, they have lots of chaulk in the underground. they make cement of it but it can be used for gypsum as well. and its cheap to produce. I did my research in importing from Taiwan, or through singapore from china of both these materials, and its possible and affordable. even with transport. import tax, and other cost. But it need to be a certain amount to be so. in China a 4x8foot 12 mm gypsum is 3 us$. AAC i dont have fixed prices on as there is soo many formats and i didnt go for one particular, but a standard stone 100x200x600 is affordable.

    I have absolutely no objection to share our conversations with other its a great plaesure to exchange ideas with someone who give things more than a short thought.

    With regards. John Thede

    Reply

  44. Hi John,

    I’m not offended at all. I appreciate having someone with so much experience and keen observations to to exchange thoughts with. Yes, it’s amusing that when a typhoon comes you want to run to your concrete house but when it’s an earthquake you run to your bamboo native bahay kubo. We are fortunate to have both.

    I worked in the field of historic restoration for many years and was an advocate for the use of lime mortars in restoration projects. I saw how old buildings with lime mortar could adapt to settlement because the mortar retains some flexibility whereas stronger Portland cement would crack, sometimes cracking brick and stone besides.

    All that said, there was a pretty big earthquake on Panay in 1948. The old Spanish stone buildings, mostly Panay’s wonderful historic Churches were destroyed or damaged whereas the American-era concrete buildings survived — the old churches being unreinforced and the newer concrete buildings were reinforced. As an American I’m not proud of the American colonial occupation of the Philippines but I am impressed with the huge investment in infrastructure during the colonial era, much of which was very well built and still in use. Almost all was built before WW II– between about 1900 and 1940. After WW II the U.S. pretty much abandoned the Philippines.

    I think that Apo is now part of Cemex, the huge Mexican cement company, or at least that’s what it says on the Apo bags.

    I could not agree more about the heat absorption of block and concrete buildings. Our apartment is like an oven. This time of year it is routinely 35C or 36C inside our bedroom. We are hoping our new house will be a little better. Our property is in a pretty flat agricultural area swept by quite strong winds. As I sit here now typing in my bamboo office it’s 35 but OK because I’m in the shade and it’s so breezy. All rooms but one have cross ventilation. All have high 3m ceilings. Roof overhangs will be about 1.4m. Windows are huge. Hopefully the rooms will cool off quickly in the evening because of the big windows and less block. Of course we’ll have ceiling fans. Our roof will have fiberglass insulation at a large ventilator at each end.

    Still I realize that overall our construction is quite conventional. Concrete and hollow block are so entrenched in the Philippines and elsewhere in the developing world. When I look at our house I realize that really it is basically built of sand and gravel held together with some cement (cooked limestone!) and steel. The blocks are certainly sand with very little cement. When these house are demolished they really are just a pile of sand!

    I know it’s popular to disrespect block buildings but Filipinos don’t build them strictly out of habit. Block house are hot but they are made with basic local materials by local workers, they are economical and quite typhoon resistant. After a flood the mud can be shoveled out and the house washed down. Compare that with wood houses in New Orleans. They are termite resistant and pretty fireproof. They don’t contain a lot of fancy manufactured products.

    But, I do admit that I too did not do any research on alternatives before starting our house. I’m quite conservative and building ANY house is a challenge to me so choosing something out of the ordinary might just overload my circuits! I don’t know how waterproof gypsum board would do here. Cement board (Hardiflex) is very popular and steel studs and other steel building systems are available.

    How wet concrete should be is a constant source of aggravation here. We Westerners are lectured about water as the enemy of concrete strength. It’s so hard to get workers to keep some slump in mixes. I had terrible tension with my workers over this and I know it’s the same for many supervising engineers who get tired of fighting with workers and just go find a place to take a nap! After taking with my engineer and reading some material about pouring concrete in hot weather, I realized that I might have gone overboard in my quest to minimize water. When it’s 35C, concrete needs to be wet enough to flow into forms and around rebar before it starts setting. This can be tough with bony concrete. I do think some allowance for conditions has to be made. Some of the suggestions in the literature are pretty amusing, such as using liquid nitrogen to cool the mix. On a Saudi office block that might be OK but in a Philippine barangay there has to be some adjustments. Filipino masons like concrete very wet so it flows everywhere and doesn’t set up too quickly. When a column or beam has voids they always blame my “dry” mix. It’s hard to tell who’s right. We even bought and used a vibrator but we still had problems despite our best efforts. I know they can make more perfect-looking work using their wet mixes and maybe they feel I’m forcing them into poor work with my outlandish ideas.

    Great to exchange ideas with you. Unless you have an objection, I’d like to include you comments in the house building blog so that others might benefit or at least argue with us!

    Best regards,

    Bob Hammerslag
    Tigbauan, Iloilo

    Reply

  45. Reply from John Thede

    HI Bob.

    Im sorry, i didnt want to offend you, but just wondered about the construction. Let me tell you a story. since 1979 i have been working worldwide, First building and managing dairies, since doing Industrial automating from offshore oil well control, and power plants, to medicine and food production. My story is from Nigeria beginning of the 1980’s. The World Bank was massive supporting agricultural development in the mid region, and lots of foreign companies came, build a company, and start the project there. One company, send big tractors, plows, Pneumatic corn seed drills. Then they first cleared some 2000 hectare land for bush, trees, anything. Start to plow the soil, harrow it, make grooves and rows of top, where the seed is put on the top as they do originally there. Then the rain season start, and a lot of soil and the seed was flushed away. WHY. Because they didnt look to what the people there have learned over 100’s of years. make the rows across the hills sides, not downhill.

    My point is, that a simple Nippa hut dont fall apart and dont kill anybody in even the worst possible scenario of a earthquake. I wont live in Nippa hut, and im sure you wont either, but the real point is to build flexible to prevent damages from earthquakes, not build in solid concrete. Your house will surely stand after a earthquake, and the roof wont fall down, but despite the heavy reinforcement, there will be cracks in the corners from pillars to Beams. And it isn’t worse than you can plaster it over, paint it and that is it. Just be sure moisture cant get to the reinforcement.

    I am from Denmark, Scandinavia Europe. Building traditions is different here than USA. We do foundations under the house, piling if the soil cant carry the load, reinforced if necessary. Then build on the frame of foundation. We DO NOT have severe earthquakes, so that is why we dont secure the walls and roofing against lateral movement, only wind pressure and heavy snow.

    Modern earthquake building method is flexibility. Steel is the main component for pillars and beams.

    I personally like to learn by the local history and see if a modern house can be combined with some of the construction techniques that has been used for 100’s of years Phil does not have a history of concrete building, we foreigners brought it there. Spanish when they came in 1600 years. brisk and mortar of burner lime and sand. Some stand after more then 200 years. Some dont. Concrete came after 2. world war. Mainly brought there by the Americans. My wife and her family live and lived in Nippa huts in the mountains in the center of Cebu island, her mom still build traditional huts but use ugly corrugated steel plates on the roof, not the Nippa palm blades they did before. Sad to see honestly but that how things change.

    Another issue, concrete and sun heat, and their ability to absorb and store heat and keeping the house too hot during nights, against the original huts, and the material used.

    Can that be combined is the question i am working with at the moment.

    How about light weight steel pipe frames as the Americans also does. Insulated, and covered with plates. How about gypsum plates. Double 12mm inside screwed on the frames. Single wet condition gypsum outside, or a shell of AAC concrete stones. (Autoclave Aerated Concrete). Or even just a steel frame, and walls of AAC ??

    Materials in phil. Yes sand is a problem as most come from rivers where it is topsoil washed out, not much to do about that, only its not topsoil as we know it, but sand and clay mostly. The clay particles is mainly flushed away so sand is left where it falls down in the river stream.

    APO cement is as far as i know a Scandinavian (Danish) build factory and produce excellent cement of good raw materials. I dont doubt to much about the quality of that.

    Mix 1:2:3 is a strong mix. Mainly for pillars that must carry lots of load. Or harbor piers where salt and corrosion is a problem. 1:3:5 would be sufficient but it dont give lots of extra cost to do 1:2:3.

    Concrete mixing. The type of mixer your using there is not allowed her for concrete mixing at all. it can be used for lime mortar, where its not used to build load carrying walls. I send you photos of the mixer type. Reason is, that the type you use need more water tro do a proper mix. where the force-mixer can do soil moisture concrete perfect. Soil moisture is, take a handful of the almost dry mix. try make a ball of it, when it stay together it is well, if its to dry it fall apart). In your mixer you could mix it dry and then add water, best if you use some detergent to brake the surface tensions on the particles, such as sulfa you use for dish washing, but you can get that in commercial product for concrete mixing. That can secure water and proper mix without using too much water. If you mix say 100 liter material, if its dry you might need up to 20 liter of water. try put in 2 drops of sulfa, see the surface tension goes, and look how the water is blended into the materials and how much less water you need now.

    Im sorry i take you precious time from your project, but i do hope some my thoughts and experience can help you.

    I will continuously follow your project.

    Thanks for your time. With regards

    John Thede

    Reply

  46. Hi John,

    Thanks for your thought-provoking comments. This whole house building process is a learning experience. Just about every friend who sees photos of our construction makes some sort of comment that it’s massive, overkill. The construction here is so different from what’s done in the U.S. Our construction is fairly normal for an engineered house in the Philippines. The footers, column sizes and beams are pretty normal for a house built to good Philippine engineering standards. The columns look big in photos because they are 30cm “wide” but the thickness is only 15cm — the same as six inch block. The column rebar is 12mm — again normal. We did use a strong 1-2-3 concrete mix, but you really can’t see that. My guess about Philippine residential engineering is that the massiveness you see is misleading. If the concrete strength was to U.S. standards maybe it is overdone, but my experience is that the concrete quality in the Philippine provinces is compromised by a number of factors. I’m not sure about the quality of the cement itself. The aggregate is sand and rounded gravel mixed with dirt dug out of a river bed. Mixing is often done by hand. High heat during the construction season can affect concrete strength. Builders skimp on mixes to save cement. So, that massive construction really can be less than it appears. Oh, yes — the hollow block is really lousy so don’t depend on interior walls to brace against lateral movement.

    You make a good point about lack of ties between the rafters. We have added collar beams. The engineers say it’s fine. We do have a bit of tie strength through bigger than normal tie beams in the interior walls — 16mm rebar in a 35cm x 10cm tie beam.

    Looking back at the project, maybe we spent a few hundred dollars on extra cement for our 1-2-3 mix. We used 6? block in the exterior walls. These are so much stronger than the 4? block which really don’t have enough cavity to contain an meaningful amount of concrete.

    Maybe I have gone overboard. If I can do things better I usually do them. This is serious earthquake country. An 8.5 or 9.0 earthquake is a certainty. I may be long gone, but I like my successors and the house to survive rather than end up as a pile of rubble. As Warren Buffet said of investing; you don’t know who’s swimming naked until the tide goes out. I can’t help but connect these sentiments to building construction too. On 14 June 1990, an earthquake measuring 7.1 in the Richter Scale hit Panay Island, killing 8 and injuring 41 people. That was a minor quake but it brought down many buildings. A 1948 earthquake caused extensive damage.

    Bob http://

    Reply

  47. I have been reading through all you description of you house project with great interest.
    Im married with a Phil woman, she is from Lutac – Naga – Cebu.
    We plan to build a retirement house in Phil, and therefor its of such interest to see your project and descriptions.
    I am originally electrician, and Later Electrical Engineer. But with a lots of knowledge in architecture and building design and construction after many years in this business.
    First of all, it hits me that all your constructions is largely overkill and i do have problems to see the reasons.

    Take the footers, pillars and beams, They seem to be planned for a 2 story building or even more. What weight are the really going to take. ?? There is no concrete slabs or deck to give weight, no 1 meter melting snow pressure on the roof, hardly water from the 1-2 mm that may give some load during heavy rain.

    I do agree, that when doing a job, do it best possible, no shortcuts, that is good labor skills and good handwork.
    Are there a special reason to choose the roof truss you do, and not a lattice truss. Do you want to use the inner height up to the truss as part the of the rooms.

    When you do the heavy steel reinforcement in the corners from beams to pillars, which earthquake types are you then foreseeing in your place.
    Lets pretend you have a 100 mm concrete deck. This will have a certain weight, and in a earthquake this weight will start to swing and even rotational swing, as its placed on pillars, which for sure will make crack between pillar and beam. BUT, that is what the concrete walls shall prevent, as they as plates will stabilize the rotational swing forces gained by weight carried on top, they will be a strong and stable structure, as big plates of not deformable stuctures.
    Some exquisite chosen walls can even be poured concrete in forms, and this, with a casting in one with the 2 pillars will be extremely stabilizing.
    My experience tells me that it is really overkill to build a 1 story building this way and with this massive use of concrete and steel roof truss.
    I even have one thing that worries me. There will be a certain pressure on the roof, and as i dont know which kind of roofing you will choose, i cant calculate the weight, but lets just pretend you want a heavy material such as concrete plates, either lighter as wave concrete, or heavy, as concrete stones. These forces from the weight will follow the elements and in the end the weight will be transfered to the beams and the pillars, all well until now, BUT to assure the force goes DOWN, and only down you must assure that the truss can take the pull out from the center, and i would say, it worries me to see there is no horizontal struts or beam from one side to the other, but only the welding in top, where 2 truss meet, and the concrete beams on top of the walls, to take the outgoing forces, this is what the lattice truss do, as the lower horizontal beam take these force.

    This is all Newtons laws of forces.

    Do i miss part of the remaining project or am i right. ??

    Are you a perfectionist who walk with braces and belt ??

    With regards.
    John Thede

    Reply

    • Hi John,

      Thanks for your thought-provoking comments. This whole house building process is a learning experience. Just about every friend who sees photos of our construction makes some sort of comment that it’s massive, overkill. The construction here is so different from what’s done in the U.S. Our construction is fairly normal for an engineered house in the Philippines. The footers, column sizes and beams are pretty normal for a house built to good Philippine engineering standards. The columns look big in photos because they are 30cm “wide” but the thickness is only 15cm — the same as six inch block. The column rebar is 12mm — again normal. We did use a strong 1-2-3 concrete mix, but you really can’t see that. My guess about Philippine residential engineering is that the massiveness you see is misleading. If the concrete strength was to U.S. standards maybe it is overdone, but my experience is that the concrete quality in the Philippine provinces is compromised by a number of factors. I’m not sure about the quality of the cement itself. The aggregate is sand and rounded gravel mixed with dirt dug out of a river bed. Mixing is often done by hand. High heat during the construction season can affect concrete strength. Builders skimp on mixes to save cement. So, that massive construction really can be less than it appears. Oh, yes — the hollow block is really lousy so don’t depend on interior walls to brace against lateral movement.

      You make a good point about lack of ties between the rafters. We have added collar ties. The engineers say it’s fine. We do have a bit of tie strength through bigger than normal tie beams in the interior walls — 16mm rebar in a 35cm x 10cm tie beam.

      Looking back at the project, maybe we spent a few hundred dollars on extra cement for our 1-2-3 mix. We used 6″ block in the exterior walls. These are so much stronger than the 4″ block which really don’t have enough cavity to contain an meaningful amount of concrete.

      Maybe I have gone overboard. If I can do things better I usually do them. This is serious earthquake country. An 8.5 or 9.0 earthquake is a certainty. I may be long gone, but I like my successors and the house to survive rather than end up as a pile of rubble. As Warren Buffet said of investing; you don’t know who’s swimming naked until the tide goes out. I can’t help but connect these sentiments to building construction too. On 14 June 1990, an earthquake measuring 7.1 in the Richter Scale hit Panay Island, killing 8 and injuring 41 people. That was a minor quake but it brought down many buildings. A 1948 earthquake caused extensive damage.

      Bob

      Reply

  48. Hi Bob, I am impressed by what appears to be a very strong roof sytem. On Liveinthephilippines.com there is a gentleman that wrote a guest column for Bob’s site and there are pictures of his almost completed house about an hour from Baguio. One picture shows his roof being installed and I have to say where your roof trusses look like an armored tank his look like match sticks. I am not saying his system is not acceptable-but what a comparison between the two. He has a beautiful home and in ways the design reminds me of what you always drew out. I am enjoying this house construction and eager to see the finished product. Hope all is well. Ron

    Reply

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