Building Your Own Home In Costa Rica – Foundations.

Hello everyone from beautiful Costa Rica! Here we are on our second week of work, full with advances.

This post in particular may be of interest you, since we are going to talk about a common problem we discovered before we started on the foundations.




There are two types of soil at our construction location. Why does this happen? Well, I was not informed of this but my client decided two years ago to fill his lot with more earth to elevate the level of the lot.









This is a very common practice but not one I would recommend. This lot has a great view to the Central Valley, so he thought that by filling the land he would get a better view. What this caused was a variation in our foundations and luckily only needed a small redesign for the foundation board.




We will also need some additional retention walls on the west side and on the south of the lot, since the weight of the house was not factored into the equation at the beginning based on this fill. I suggested we use tires for the retention wall to reduce the cost of this unanticipated change.




When you plan any kind of a big movement of the earth on your lot, it’s better to get some professional advice.




With the help of the soil tests, our structural engineer and my ‘commonsensical’ thoughts, we decided to bring our foundations to a more superficial level. They were designed as deeper foundations: up to 1 meter. But this hummus layer will make us go deeper than that, ( maybe 2 meters or more) ending up in a costly, unnecessary foundation.









Our decision was to go only 60 centimeters deep from soil level, with a wider trail of 75 cms (it used to be 40 cms). This is necessary to give the house the right structural conditions for the present soil conditions, and more stability.




Now it is time to excavate at the correct level, trying not to move our nylon lines. After a proper compaction, in this case done by hand, not with a machine because of budget limitations, we will have a 35 centimeters ballast base (it’s common to have less), then we will pour a 10 centimeter quality concrete (usually you use poor concrete), then we will locate our armors, and then fill with concrete again up to 20 centimeters, as shown in the picture.




I wrote down all these details in our bitacora which is the very important notebook that keeps track of every construction phase going on. Without this book which must be completed by a licensed architect in Costa Rica, you’re not able to build. Municipality and CFIA always check that it has professional annotations, meaning it is been supervised by an approved professional.

With our foundations’ level defined, this is how armors look like, we call it canastas which is baskets in English. All the steel required has been approved. The place where we bought it is a trustful source, given us the desired quality.




We buy materials at a nearby Lagar hardware store. They have sold quality materials over years. These canastas were prepared in advance by one man following measurements indicated by our structural engineer. All hoops are #3 rods (according to Costa Rica Seismic Code) and #4 rods in the corners.









With our foundation poured, the next step is to locate one line of block, and the metal plates that will serve as a basement for metal columns. They have #5’s welded to it. These are curved rods that get into the canasta, before pouring the concrete.




We also need to get ready the bathroom’s module, that goes all in decor block up to the second floor. Here we are calculating the correct block distances and locations, in order to work with a module and don’t have any waste. It has been designed like this, now it is been tested.




I designed this bathroom module all made out of block for two reasons: one for structural stability give to the rest of the house structure, and second to have a thick, protected wall which should resist rain, humidity and winds.









It is located in the northeast section of the house, meaning that this wall will receive the largest amount of rain. Northeast is an important facade in the Central Valley which needs to have special attention.




With our foundations poured this week, then we can move on to the most interesting part of the project – metal work.

Written by Costa Rica Architect Gloriana Mejia who focuses tropical modern architecture and believes in following very basic principles: simplicity as a guide for good design, compact areas as a solution for space, passive solutions for sustainable architecture and context as a main character of the frozen music that architecture is….

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Andrew Makarik

to@welovecostarica.com

Andrew Makarik is the main editor of WeLoveCostaRica, a fan of this sunny country. He is also a loving husband and a has a lovely daughter. By being a devoted family man and the biggest Costa Rica fan, he wants to make more people feel at home there. WeLoveCostaRica unites people and helps them find new home or a new travel destination. This website is a friendly community where everyone can find not only information, but also new friends and travel pals. Andrew is also passionate about IT and programming, so he himself maintains a friendly atmosphere in this cozy environment of WeLoveCostaRica.com.