Construction Project: Casa "La Esperanza"

Stage 2 - Foundation

This marks the beginning of the much more substantial phase 2 of our construction (plus completing phase 1 and remedying its structural and cosmetic defects).

This page describes construction of the 1.8 meter deep reinforced concrete foundation, plus completion of the boundary wall in obra negra and some remedial work.

The total time taken for the work on this page is about 7 weeks. Click here to see a summary of masonry costs for this stage.

Page Contents

Week 14: Rubén's initial visit to the site, the start of Rubén's work and over four and a half days of excavation. A chaotic site is transformed into a well-organized one, and the doors of the portón are fitted so we can close them. But numerous defects are noted in the work of "maestro" X.
Week 15: Work following the excavation includes filling in with filtro and compressing, laying some of the plantilla, and then assembling some of the contratrabe. They are also finishing the fachada wall. We are impressed with the pace and quality of work.
Week 16: The plantilla and contratrabes are mostly done, and the fachada wall and large marquesina are complete. However, the trabe failed as "maestro" X used more steel than the engineer recommended claiming it would give more strength, while surrounding it with insufficient/poor-quality concrete.
Week 17: The foundation reinforcements are mainly complete, and some of the wood for forming the concrete is in place. The side wall is also completed using some inventive scaffolding.
Week 18: Fitting of wooden molds is complete, ready to receive the concrete (all 51m³ of it). To mix, haul, and pour this, 20 additional workers are hired (to give a total of 30). The rear boundary wall is also completed.
Week 19: The foundation walls are completed.
Week 20: The foundation walls are sealed with impermeabilizante and an excavator is used to start filling the cavities with filtro to make the floors. There is also more excavation for the entertainment area, and the columns at the front of the house are poured.

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Week 14
08 Jun 2014	Our first view of the site the day after "maestro" X finished here; we took our new maestro Rubén along to survey the damage. Rubén just had to laugh when he saw the utter shambles that "maestro" X had made of this simple work.
08 Jun 2014	Verónica with our saviour Rubén. Simultaneously, Rubén and I noticed a blatant construction flaw - that the columns were completely detached from the adjoining walls rather than tied by varilla - hardly acceptable in an earthquake zone! And it is clear that this was their finished work.
08 Jun 2014	Another view showing debris strewn around the place.
08 Jun 2014	The area around the storage room, with wood still around recently-built walls. As can be seen, only this wall to the left side is nearly complete - the other three walls have only been built to 2.5m. The fachada, with its ludicrous mortarwork and hideous columns, seems more intended to induce mirth than provide an elegant exterior to the property.
08 Jun 2014	The small door opening was very unstable and could be easily moved back and forth a significant distance by hand. Subsequently the walls of the storage room were also found to be very weak. 12 Jun 2014 (Thursday): Start of excavation and Rubén's work.
14 Jun 2014	This is the first day we saw of Rubén's work here. Excavation was still in progress, and would not be completed until next Tuesday. Rubén had organized a shaded area to the right, and they were making steel reinforcements for the foundation. There are only three or four of Rubén's people working here at the moment, but once the excavation is done this will increase to 10.
14 Jun 2014	Everything is now well organized, unlike the previous chaos. The wood from "maestro" X has been removed (he also took molds for the marquesina which were not his to take). The corner of the small marquesina broke off (apparently when the wood was removed) - this does not say a lot about the quality of his concrete. It seems he was also unpleasant with Rubén when he collected the wood; for reasons best known to himself, he boasted (falsely) that he had built the property to the left (Rubén responded with the fact that this construction is also seriously defective)...
14 Jun 2014	The herrero was fitting the steel doors. Replacement wood has been delivered. Rubén has saved some of the revuelto pointlessly placed by "maestro" X. Note the preassembled reinforcements to the left, made with lengths equal to the heights that will be required (unlike the practice of "maestro" X). These include properly-made columns for the entrance to the house, having a circular cross section.
14 Jun 2014	This is some of the excavation for the house, which will have a proper reinforced concrete foundation. Two or more trucks were alternating taking away the soil, with an excavator working continuously. The complete excavation for the house required removal of 111 truckloads of soil plus 43.5 hours excavator time (further excavation will be required for the entertainment area). Rubén noted several cracks in the rear wall due to defective construction of the foundation (this from someone who claimed to have a special technique here). We later found other cracks in other walls. We hope that these are from one-off movement and will not develop further. Rubén suggested reinforcing the wall with steel mesh then filling with concrete to deal with these cracks and compensate for the lack of castillos. He would also make cadenas to tie the walls to the house foundation at the level of the dala de desplante (the proper design was for the walls also to have zapatas corridas and be tied at the contratrabe).
14 Jun 2014	Fitting of the doors is nearly complete. When we left, we were able to lock up the site and give the key to Rubén - a great day! The columns have been tied to the walls, and Rubén said he can fix the numerous other problems left by "maestro" X. We were very happy, for the first time in many weeks.

Week 15
18 Jun 2014	The first day after completion of excavation; already parts have been filled with filtro, then sand on top, compressed with the bailarina shown, then a 10cm thick concrete plantilla made. The white marks indicate positions in the foundation.
18 Jun 2014	The other side of the area of the foundation. Rubén recently visited the civil engineer on two separate occasions to clarify a few of the specifications he made regarding the foundation. Obviously, Rubén takes plans seriously! But he was given some incorrect figures by a student, which we believe led to the living room being made 30-40cm too short.
18 Jun 2014	Smoothing the plantilla.
18 Jun 2014	A view from the rear - they are also working on the fachada. We are already very impressed with Rubén's work. Some of the positive attributes we noted (and which I also noted during the construction of "El Refugio") are: Rubén works from plans, and respects instructions given by clients. Rubén is well-organized, and always plans his work and thinks ahead. Rubén is highly skilled and capable, with a very wide range of experience... Rubén nonetheless discusses issues with his albañiles, thus utilizing the experience of the entire team. Rubén and his people are highly productive, with a great work ethic. Rubén has a sense of duty - he later had several offers of work, but made plain that he had a commitment with us. Rubén feels personally responsible for the quality of work done, and (we are quite sure) would never think of blaming his workers for shortcomings. Rubén clearly keeps a happy, motivated team - important considering the hard work they do. "Maestro" X demonstrates the exact opposite of all the above characteristics.
18 Jun 2014	A view from within the foundation. The level of the path around the house will be a few centimeters higher than the top of this dala de desplante (parts of it in black).
18 Jun 2014	A view from outside - the place is now a hive of activity. Apart from working on the foundation, they are also working on the fachada, and have already completed the tabicón as far as the portón.
19 Jun 2014	The next day showed significant advancements on the foundation - this is the plantilla in the area of the laundry room and stairs to the roof. Verónica is holding two of the plans for discussion with Rubén.
19 Jun 2014	Laying the base of the zapatas corridas by the side of what will be the main living room.
19 Jun 2014	A view over the other side.
19 Jun 2014	Work is also continuing on the fachada wall; they are now at the level of the dala de coronación. There is no attempt now to finish the tabicón attractively, since it will all be covered over. The mortarwork is nonetheless a good deal better than that of "maestro" X (and they are using proper mortar!).
21 Jun 2014	The left side of the foundation, two days later.
21 Jun 2014	The right side.
21 Jun 2014	They are now assembling the contratrabe which will be fitted over the zapata corrida. It has been raised off the ground to make work on it more ergonomic.
21 Jun 2014	The area that will be the large living room.
21 Jun 2014	A more general view of the foundation to date.

Week 16
25 Jun 2014	A similar view four days later.
25 Jun 2014	The sloping roof of the main marquesina is under construction, and the fachada wall is complete. They are using light concrete made with hormigón to finish the marquesina.
25 Jun 2014	An external view of the fachada, with work taking place on the marquesina. The malla is for reinforcing the losa of the marquesina.
28 Jun 2014	Another overview of the foundation.
28 Jun 2014	The roof of the marquesina has now been completed (in obra negra - it will later be finished and tiled). BUT: The doors that we were happily able to close two weeks ago will close no more, since the trabe from which they hang has failed (although "maestro" X said it was built with more steel than the engineer recommended). This is as a result of the steel having pulled through the surrounding concrete; either because there was insufficient concrete surrounding the steel, and/or because the concrete was of poor quality. Another serious defect from the know-it-all "maestro" X, and one which we fear will be difficult to remedy. The corner of the small marquesina that broke off is clearly visible here, and is hardly a good indication of the quality of his mixes. We are also concerned about the septic tank and storage room above it. It seems that the brick walls of the storage room simply sit on the septic tank. Furthermore, Verónica is sure that he did not reinforce the base - this is since she recalls previous work on an aljibe in which she said he simply stuck the castillos in the ground ☹ We gave him a photo that clearly shows reinforcements, but this does not give us any assurance that he bothered to put any in.
28 Jun 2014	The foundation from in front of the living room.

Week 17
02 Jul 2014	An overview of the foundation, showing a lot more zapatas corridas and some of the castillos in place. This is where all the action is now, except for some work on the side wall. At 300m² , the house footprint is significantly larger than that of "El Refugio", but this house will have only a single story.
02 Jul 2014	Another view, from by the living room. There should be a cadena running across the middle of the living room from the contratrabe to the right (this will be fitted later).
05 Jul 2014	The first thing that greeted us on arrival today was this wonderful structure for completing the side wall - a Rubén/Méxicano special (I saw several other examples in the construction of "El Refugio"). You don't get the Health and Safety people around these parts...
05 Jul 2014	A view of the right side of the foundation from by the living room - the reinforcements here are now essentially complete.
05 Jul 2014	Another view over the living room, showing the reinforcements and plantilla for the cadena now in place. The herrero arrived earlier this week to fix problems with the door not closing, and now the left half closes - but unfortunately not the right. We can nonetheless lock the door and wait for an herrero of Rubén's to fix this and other issues. We hope the issue with the trabe is a one-off, and that we can work around the defect.
05 Jul 2014	Another view over the foundation from by the improvised scaffolding. Some of the wood for forming the concrete is in place.

Week 18
09 Jul 2014	The inventive scaffolding has been removed as the side wall is now complete, and they are now working on the rear wall (which can be reached from outside). There are more wooden molds for forming the concrete. We will need over 51m³ of concrete to fill in the zapatas and contratrabes comprising the base of the foundation (the zapatas are 1 meter wide and filled to a thickness of 17-20cm, with contratrabes over measuring 40cm x 15cm). The most convenient way to do this would be to use ready-mixed concrete with a pumper truck. But here in Mexico, this is substantially more expensive than buying the ingredients and hiring a couple of concrete mixers and numerous workers to mix, haul, and pour the concrete by hand...
09 Jul 2014	Work in progress on the rear wall. The top of the dala de desplante (black) is the nominal ground level, with the wall 4m high above this; however the ground slopes gently downwards and so the effective height of the wall here is significantly greater.
09 Jul 2014	Another view of the foundation assemblies. Some of the steel reinforcements have rusted superficially in the rain, but this should not have any significant adverse effect.
09 Jul 2014	Foundation assemblies to the left. Apart from the contratrabes that will support walls, there are also cadenas that are purely for the purpose of tying together elements in the foundation; an example is that across the living room to the left. These are to resist the forces that can arise in earthquakes.
11 Jul 2014	We have 30 people working here today with 2 concrete mixers to pour the zapatas, contratrabes and cadenas of the foundation base. The ingredients for this are: 22 tonnes (440 sacks) of cement, 30m³ of sand, 24m³ of gravel, and an unknown (but considerable) quantity of water. The sacks used here are 50Kg (illegal in many countries, where due to health and safety regulations, the maximum size is 25Kg). All the above materials must be mixed, carried in buckets to where it is needed through the numerous obstacles of the foundation reinforcements, and poured. At the moment, they are taking a well-earned break from this huge and arduous task. I am not happy to see humans used in this way when there is an easy alternative in the form of ready-mixed concrete with a pumper truck - unfortunately there seems to be a monopoly in this (at least in this area) and it is overpriced.
11 Jul 2014	The tabicón in the boundary wall has now been completed. The entire wall will later be reinforced with steel mesh to compensate for the lack of castillos and other structural problems from "maestro" X.
11 Jul 2014	As can be seen, a considerable amount of wood is required to form the concrete, rather more than is currently available. It is hoped to be able to re-use some of the wood by removing it where the concrete is sufficiently hardened and using it elsewhere.
12 Jul 2014	The foundation base has now been poured, and we are back to our usual complement of 10 masonry workers. The material consumption too will be less for the moment, although the foundation walls will require around 6,000 tabicones (11cm x 15cm x 28cm).
12 Jul 2014	This is the rear wall and that to the side, now all completed.
12 Jul 2014	And this is the fachada, also completed (in obra negra). There is a striking contrast between the aparente mortarwork of "maestro" X (lower courses) and the obra negra of Rubén's people (above the middle row of adoquín). Rubén's work on the sloping part of the large marquesina also contrasts with the ragged work on the small marquesina done by "maestro" X. It is a sad reminder that had all this work been done by Rubén, we would have the attractive fachada sin acabado that I designed, without further trouble and expense. But thanks to the ineptitude of "maestro" X, we will have to cover it all over; this applies not only to the walls themselves, but also to the ugly columns. For the walls, I plan to use diamonds of cantera surrounded by textured concrete. Rubén says he can finish off the columns attractively without using paint. The two marquesinas will of course be covered with the same tiles that we will use for the house. But we will leave all this until after the house has been completed and the structural issues with the fachada have been remedied.
12 Jul 2014	An overview of the site from by the fachada.

Week 19
16 Jul 2014	Now the foundation walls are being built. The dala de desplante of the house foundation (already made on the left wall) will be just below the level of the path (and higher than the dala de desplante in the boundary wall), to drain water to the front of the property.
16 Jul 2014	An overview, showing some of the wood that has been removed from the foundation base.
16 Jul 2014	A view of the right side of the foundation, showing more walls. All the cavities in the foundation will be filled in with filtro.
19 Jul 2014	Some of the foundation walls have now been completed with the dala de desplante laid on top. This is a view of the right side of the foundation...
19 Jul 2014	...and this is a view of the left side. The damp-proof course will be laid on top of the dala de desplante.
19 Jul 2014	An overview from by the fachada.

Week 20
24 Jul 2014	More foundation walls have been built, and now they are being covered with impermeabilizante on top of asphalt sheets to make the damp-proof course.
24 Jul 2014	Another view from by the living room - they are removing the wooden boards.
26 Jul 2014	The foundation walls are now done, and the whole area must be filled in with the red filtro shown. About 90 truckloads of this will be needed.
26 Jul 2014	A closer view of the foundation walls. Once filled, the material must be compacted with sand on top to give a solid surface on which the firme for the floors will be poured.
26 Jul 2014	The bases for the columns at the front of the house have now been filled. Also some more excavation has been done for the entertainment area.

The foundation is now complete, but it still has to filled in with considerable quantities of material to make the floors. It has been a time-consuming and expensive affair, but we cannot have second-best here - especially in this type of soil. We only regret that the boundary wall has an inferior rock foundation, rather than being done the same way at the same time by the same people, and tied to the house foundation.