Our Philippine house project: layout, footers and columns

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Building our house in the Philippines. January 15, 2010.  After months of planning and many changes we finally have our house plans completed, we have a foreman and crew and are ready to start construction next week.

This is the design we’ve settled on.  More detail on how we chose this design at /our-house-project-design-devolution/

A perspective drawing of the house we'll build

Beginning to layout the house foundation

The first glitch occurred when the foreman doing the layout assumed that the front of the house faced the road to the south. The house actually faces north toward the mountains. As a result, much of the layout was reversed and had to be redone. Fortunately, no concrete had been poured and the corners were correct.

Rebar cutter in action

Our first load of rebar was delivered — 450 six meter long pieces.  All of these need to be cut and formed.  We bought a rebar cutter to speed the process, being shown here snipping 16mm rebar.  On our wall construction project we cut all the rebar with hacksaws. The rebar cutter really speeds the work.

Foreman Tatoy fabricating rebar cage to reinforce our corner columns

This photo shows foreman Tatoy performing part of the big job of fabricating rebar cages.  This one is for a house corner column.  It six meters long.  The long vertical bars are 12mm and the stirrups are 10mm.  The rebar seems to have been made at Qian’an Jiujiang Wire Rod Co., Ltd. in China.  They claim to make 16 millions tons of steel products per year.  We paid (Jan 2010) P288 for 16mm rebar, P163 for 12mm and P113 for 10mm.  We are paying P209 for a bag of cement, P300 per cubic meter of sand and P420 for stone.  Sorted, washed 3/4″ stone is much more, P700 per cubic meter.


Column footer

This is a good overview shot showing how most construction is done in the Philippines.  This shows a column footer excavation which is 1.2 meters (about 4′) below natural grade.  The footer is one meter square.  A 8X8 mesh of 16mm rebar is at the bottom.  The column rebar core rises almost six meters (about 20′) above the bottom of the footer.  This rebar core will be encased in a plywood form into which concrete will be poured and then vibrated in an effort to ensure that there are no voids.   Easier said than done!   This is what greeted us when we removed the form from our first column.


The complicated rebar framework devised by our engineer is much more demanding than the usual square column with a vertical rebar in each corner.  Getting the wet concrete to flow through the multiple rebars is a challenge, especially when trying to avoid over wet concrete.  It’s a perpetual struggle to keep the workers from making the concrete too wet.   Another factor,  we were using 3/4″ gravel rather than the sandier gravel which is typical here.  The gravel “hung” in the rebar framework leaving big voids.  We demolished this column.  You can be sure that this kind of a problem wold be quickly hidden away if you are not on-site supervising.

Editorial comment. If we had it to do over again,  we’d use plain square columns rather than the complex design devised by our engineers. While there may be advantages to the design our engineers provided, the practical problems of building them correctly in the provincial Philippines are several.  Our good, experienced workers had no experience with such columns, or generally such complex rebar configurations.  The aggregate generally available in our rural area contains larger stone which tend to hang up in the small openings.  We had the advantage of a good crew who wanted to good work. a concrete vibrator and screened gravel.  Still we had continuing problems and wasted lots of time trying make good columns using the design we were supplied with. In a situation where supervision was lax the situation would be worse.  Trying to fill the complex framework, the workers would use soupy concrete.  Any voids and defects would be plastered over.  The real world end result could easily be a significantly weaker column than employing the usual simple  square column with four vertical rebar.

An almost perfect column

The rebar at the top of the columns will be tied into the reinforced concrete beams which top the walls of the house.  These elements make a strong, well-anchored frame which is filled in with weak hollow cement blocks which are also filled with rebar and concrete and then parged with a thick coat of stucco-like concrete.  Metal roof trusses are also anchored into the concrete room beams.  The trusses will support long span steel roofing.  We decided to use 6″ hollow block for the exterior walls and four inch block for the interior partitions.  We are purchasing our block from Damasco in Pavia, Iloilo.  We used Damasco block for our perimeter wall.  In our view Damasco is the gold standard for block in Iloilo.  One does pay a premium. Local four inch hollow block costs P9, delivered.  Damasco 6″ block costs P13 delivered, 4″ Damasco block costs P12.   Using better block is a minor extravagance as the cost of block is a surprisingly small part of total construction cost.  More on hollow block shopping at /our-house-project-cement-blocks/

At the end of our first week of construction the first concrete is poured

2″ X 2″ lumber is a staple of construction in the Philippines, used for layout as seen above and with 1/2″ marine plywood for building forms.  Typically the 2X2 is “coco” lumber – lumber from the coconut tree.  My foreman insisted that we buy mahogany instead, saying the coco is dangerously weak.  I reluctantly agreed – coco is P55 for a 2x2x8′, mahogany is about P75 and we needed a few hundred pieces.  Now I’m a convert.  The mahogany is stronger and more durable.  Coco lumber in forms under under pressure from wet concrete does give way more easily.  I do feel guilt.  Much of the mahogany is beautiful furniture grade material.

A ponke in action

This photos shows the workers adding material to the mixer using a “ponke”.  The ponke is a wooden box with handles.   The ponke is sized to hold one sack of concrete, 30cm x 30cm x 30cm (one foot square).  I asked that the ponkes be built and used as a means of controlling the concrete mixture.  We decided on a mixture of one part cement, two parts sand and three parts gravel – a 1-2-3 mix. The use of the ponkes makes it easy to get the mixture right.  Ponkes are rarely used in the Philippines now, but used to be common.  Now materials are more commonly measured using empty cement sacks refilled with sand or gravel.  I wanted the ponkes and my ever patient crew accommodated another whim of the kano.  (Anyone with information on the correct spelling and etymology of “ponke” please leave a comment.   It sounds like it may have a Chinese origin.  This makes special sense as Chinese workers were prominent in the Philippine construction trades.)

One of the crucial advantages of being you own contrator is that YOU control the quality and quantity of concrete and reinforcing bar.  If you don’t think this is important, study the photos of the Haiti earthquake.  While there was widespread destruction, many building survived with little or no damage.

Our 1-2-3 mix is almost considered to be an extravagance.  The house you buy already built probably won’t have such strong concrete.  1-3-5 is in common use.  I have seen deliveries of substandard reinforcing bar.  A poorly built house may be built with a “class B” or “class C” concrete mix and not enough rebar.  You’ll never know what’s in your house unless you build it yourself.  It might never matter, but here’s a photo of the church in nearby Oton, Iloilo which was destroyed in the January 28, 1948 Panay Island earthquake.  You can still see damage from this earthquake at the Alimodian church, only a few KM from our Tigbauan site. Also see http://earthquake.phivolcs.dost.gov.ph/update_SOEPD/Earthquake/1990PanayEQ/index-panay.html regarding the 1990 7.1 Panay earthquake which collapsed buildings in Culasi and elsewhere.

The plan of our house was designed by a structural engineer.  We’re trying to be quite strict in following the plans.  We see quite a bit of good engineering in the plans as we build.  Lots of reinforcing steel is used in critical areas, but much less in columns not carrying much load.  Sometimes Filipino builders use traditional rules of thumb not based on engineering basics.  This can mean too much steel in places which really don’t need it and not enough in others.

Magnificent Oton Church, destroyed by 1948 earthquake

Concrete vibrator in action

Look closely and you’ll see the worker using a length of rebar as a probe.  They’ve learned that large pieces of gravel can become lodged in the rebar preventing the flow of concrete down the column.  The internal concrete vibrator (more info at /our-house-project-equipment-shopping/) makes the concrete flow better but can’t be depended on to dislodge stuck gravel.

Our latest response was to screen our gravel exclude larger stone that could hang up in the columns or beams.  We built a simple screen for our gravel using hardware cloth with a 1″ x 1″ mesh.  About one-half of our supposed 3/4″ gravel makes it through this mesh. We will use the smaller material for critical uses such as columns and beams, the larger stone is used in footers and fill for the hollow block.

Our conclusion is that the concrete vibrator caused more problems than it solved.  Most this is because most of our workers had never used a vibrator before and over used it.  In the case of columns, over vibration caused a slurry of water and cement to drain out of the bottoms and sides of the forms.  Left behind were the aggregate but not enough cement to hold it together.  This is shown in the photos below.  Probably with trained workers and larger projects, concrete vibration results in higher quality concrete but for us that was not the case.

The effects of over vibration at the bottom of a column pour.

A column error corrected.

Here’s another worker error caught by our engineer.  Generally the column rebar goes up first, then footers for the hollow block walls.  Then the walls go up around the column rebar. The pouring of the column is the last step.

Here the workers put the hollow block almost against the rebar cage for the column, leaving no room for the concrete forming the column.  This would have resulted in a much weaker column because the block has little strength.  The solution was quite time consuming, chipping or cuting back the block to give one inch of clearance between the hollow block and the column rebar.  With hollow block filled with concrete, this took quite a bit of time.  My foremen, who have built many houses, allowed this to happen, suggesting that it was their usual practice.

Read all about our Philippine House building Project at /building-our-philippine-house-index/

Comments (22) Write a comment

  1. Hi. Good day. Its very informative blog.
    For that ponke 30x30x30, how many water needed for class A and classB?


    • We did not measure water. The crew knew about how much to add and then we added more to get the right slump. If we added too much, we would dump the mix and start over. After a few dozen mixer load, the crew will know what you want. Perhaps there is a better way?


  2. Thank you for taking the time to discuss in detail your house. We want to build a one storey house and wanted to inquire if you can share the room layout.


  3. Thanks for a lot of very useful information. I have got a beachfront lot and an old house to fix up in Negros Occ., and I’m trying to buy a concrete mixer. Do you consider sell yours if you have still got it?


  4. Hi Bob,

    Helpful informations you have here. May I ask you help please. Can you please give me the measurements of the corner rebar configuations you have in your house. and also the spacing measurments of 12mm rebar on the column and stirrups spacing. These will be a big help to me. I am planning to add 2 more rooms for my house in Manila and these rebar configurations is what i am planning to build in the corner of the rooms.
    Thanks in advance.



  5. Hi Bob, how did you decide the dims for the ponke ? Converting them to my inches i make it 16ins (approx) square that gives 2.3 cubic feet. I am having a problem with working out the trips needed to the mixer with your 1.2.3. mix
    One bag of cement would be 1 cu ft and easy to dump into the mixer over the dry sand and gravel. Sorry for my arithmetic better with a screwdriver!

    How did the guys work with the ponke you made, heavy enough or could it be larger?



    • Peter,

      Workers almost always use empty cement sacks for measuring sand and gravel. I probably would not bother with ponkes again. They really do not offer any better control over mixes than cement sacks. Our mixer was a “one bagger” meaning it could handle one sack of cement and the necessary sand and stone. The wekest mx we used was 1-2-4 for the floors so the mixer held seven sacks in total. The size of the ponke was intended to be a sack of cement. This is all a bit crude. As I understand it, the mixes (say 1-2-4) are supposed to be by weight, not volume. Generally we used 1-2-3 so hopefully we have enough strength to make up for any variations in the proportions.



      • Thanks Bob, your blog is really a big help… using 40cmx40cmx40cm is wrong I dont know where they got this proportion. The traditional wooden box “ponke” to measure sand and gravel is 30cm x 30cm x 30cm a volume net of 0.027 cubic meter (1 cu. foot). Concrete proportion by volume method is widely used in the Philippines. For example use class “A” mixture 1 : 2 : 4 therefore, 1 bag(40kg) of cement + 2 box sand + 4 box of gravel the same method using empty bag of cement. I suggest you can buy a book in national bookstore regarding construction in the Philippines it can help you a lot & for me I prefer Simplified Construction Estimate by Max Fajardo.
        I hope I can help.



        • Lmer,

          Thanks for your comments — and your careful reading. Certainly the size I gave for the ponkes must be wrong. 40x40x40cm = 2.26CF or a like number of bags of cement. There is no way our ponkes could hold more than two sacks of cement! I no longer have any of the ponkes to verify the measurements, but they did hold just one sack of cement so they were not 40x40x40cm. We bought a one-bag mixer. Our theory was that it would make it easy to mix the mix we wanted. So, if we wanted 1-2-3 concrete, we’d use one ponke (one sack) of cement, two ponkes of sand and three of gravel. Of course the general practice now is to use empty cement sacks for volume measure. The crew really did not see the point of the ponkes when we could just use sacks like everybody else but they were cooperative with these strange notions. There was some advantages to the ponkes when adding material to an operating mixer. It gave better control and less material ended up on the ground instead of in the mixer — as you can see in the photo. Thanks again!
          I do have Fajardo’s book. It was very helpful.

          Bob and Carol


    • hi. I think “ponke” must be 1ftx1ftx1ft same as volume of 1 bag of cement@40kg. It would be easier working with the proportioning of aggregates.


      • Andrew,

        Thanks for pointing out the error in the ponke dimensions — and to the several other posters making the same point. 40cm x 40cm x 40cm ponke hold much more than one 40 kilo bag of cement. The correct size is 30cm x 30cm 30cm.



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  8. Citas,

    Here’s something I wrote about how we ended up changing our plan from two-story to one story.

    Thanks for you appreciative comments about the house design. We had been working on it for three years, ever since we saw a similar design in historic Lucban, Quezon but we have to break the news that at the last minute we have abandoned this design and have decided to build a one-story house. I suppose our decision is really a triumph of practicality over aesthetics.

    We had lots of good reasons for wanting a two story house. We wanted a perch where we could have an unimpeded view of the mountains and surrounding rice fields. We wanted to reach up to the cool night time breezes. We wanted to have a second floor refuge from any flooding, especially after experiencing Typhoon Frank in Iloilo City. I wanted an upstairs refuge from the family hubbub downstairs. An upstairs bedroom seemed more secure from robbers. Those were the advantages we saw, on top of the instinctive aesthetic appeal of the two story house. Psychologically, it was perching above rather than crouching below. My mother-in-law says there are two types of homes and home owners, “perchers” and “nesters”.

    The building of our bahay kubo helped change our mind. As is traditional, the floor of the bahay kubo is about one meter above grade. This makes a standing adult above the level of the top of our eight foot fence. We are surrounded by land which either has already been subdivided or in in the process of subdivision. The pace of development in the Philippines is such that land around us will be developed, sooner or later. Our lot is only twenty-three meters wide. Our second floor would give us a ring side seat to whatever was going on a few feet away, karaoke, TV, crowing roosters and all the other aspects of exuberant Filipino life. If we built a single story house, our eight foot high concrete wall will provide a considerable buffer from whatever noisy chaos eventually surrounds us. I’m a little embarrassed to show how shallow or thinking was, but there you have it!

    There are other advantages to the single story design. This is earthquake country. Panay had an 8.5 earthquake in 1948 which destroyed many buildings. Proper engineering for a two story concrete house (most are NOT properly engineered) calls for lots of very expensive 25mm rebar and steel decking to support the second story floor. A one story house is simpler, more or less like our fence with a roof. Our property is unusually exposed to typhoons. We are one kilometer from the sea on a flat, exposed, treeless plain. That gives us good breezes when it’s hot, but the typhoons will really blast us.

    We came to realize that our experience with flooding in Iloilo City was not very relevant to our Tigbauan property which is about fifty feet above sea level and did not flood during Frank. Certainly the two story house would survive, but maybe we’d be a bit more comfortable hunkered down in a one story house.

    More importantly, we are enjoying having Carol’s niece in Tigbauan, sending her to school here and generally trying to give her a better future. Carol’s sister has also been staying with us. The only story house is less elegant, but gives us another bedroom for another niece or two. Eliminating the stairway and second floor complexity allows us to have a four bedroom house for less money than the three bedroom two story house.

    So what is our substitute design. Some months ago we visited SOS Children’s Village in Zarraga, Iloilo. This is a residential community for children. The residence buildings are said to have been designed by a Cebu City architect. I really liked the design because it incorporated the feel of a Filipino traditional house, especially the roof structure. See http:///sos-childrens-village-iloilo/ So, after years of refining our two story design we switched gears and came up with a new floor plan in a matter of hours. We are in a rush because we’d like to start construction in January. After an initial gulp and a payment for work already done, our engineer has been very cooperative. We expect to have conceptual plans by the end of this week. We’ll post the plans once we get them.



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  10. We have the same idea about facing the mountain view.We will be visiting at the end of this year to see our building site. So, don’t sell your equipment just yet; we hope to start
    building in the mid year of 2011. We currently have a one level house but because we are trying to take advantage of the view, we are thinking, our house guests can do the stairs and we will have our bedroom in the first floor. What
    made you change your mind?


  11. Wonderful news!! along with the drumbeats of Dinagyang, one could hear hammering and sawing from your lot in Tigbauan..will bring an early housewarming present for the house. we are flying on the 24th–Phil. here we come!!


    • Natie, we had not thought about it that way — wow! Look forward to seeing you. Have a good trip. Bob and Carol


  12. Thanks!
    I am excited that the work will start. Do you have the plans, so that we can compare it with the final result? hehe.
    I think it is good that you go for quality. Firm concrete also keep water and moist away.
    The Briggs and Stratton machine makes me remember my childhood. My parents build it in in their rowing boat about 50 years ago in Norway. The engine survived the boat itself.
    We are following you…


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