How to build a house in Costa Rica
Stage 2
OK, now we have decided that we are going to build out of block. The first step is to lay out the house with string starting with the outside walls then the interior walls. The strings are the center of the wall and we attach them by building wooden corners with nails. Once this is done, one wall at a time we put two nails 7 inches ( it could be more if the house is more than one story because you may need bigger footings) on either side of the string nail and attach two more strings making the center one the middle and the other two the outside of the wall. We then remove the middle string and begin digging out the footing. The footings will be at least one meter deep. Although, depending one where you are building and the type of soil you may need to go much deeper. I should also point out that in Costa Rica all walls are done the same, so your interior walls are exactly like the exterior making the house very solid and virtually sound proof inside. We continue this until every wall is done.
The next step is to lay a layer of pure concrete of about 8 inches ( again it could be more depending on the terrain or number of floors.) I have seen many builders not put the concrete down first and only lay a layer of gravel ( piedra cuarto) but I do not agree with this. I believe you need a solid surface to start. While all this is being done you will have a crew making rebar forms ( placas.) We make these by putting 3 or more lengths of rebar #4 ( 1/2 inch called baria) side by side and putting smaller pieces of rebar that has been made into rectangles over the lengths of rebar and tying them together with 10 inch lengths of wires. This is hard to explain without seeing it but the wire is twisted and then a tool that looks similar to a pair of pliers is used to twist to make a knot and pull everything tight. When these three are all put together you flip it over and attach three more making a long rectangle box of rebar. Again, the size will vary based on the house being one or more floors.
Once all the placas are complete and there will be quite a few of them, for this house we need eighteen at six meters long, we place then into the footing holes and attach them to one another. We will now attach rebar to the placas perpendicularly every 20 centimeters. In addition to making the placas your crew will be making a very similar rebar box to put in for the corners and columns ( columnas.) The columnas will be in differant shapes depending on where they are going but are made the same way. You will have some that are rectangle and are put anywhere the extra support in needed, some will be T shape for where walls come together and L shape for the corners. We will need twenty two total for this house and they are all tied to the placas with the same twisting of wire. That is all for now, stay tuned for the next stage. Pura Vida
