How a Foundation is built?
When you are building a home in a cold climate, you are almost always going to have a basement. When you start your basement, your excavators are going to come in and dig a hole down to about the lowest level which they call a footing. Now, the footing is what the rest of the house will rest on. Not only the concrete wall that supports the home but the home itself. So, a footing tends to be 2 foot wide, 8-12” thick because it needs to carry a pretty heavy load.
The excavator is going to dig down to the bottom of the footing and clean out the entire hole giving the workers who are going to put up the concrete wall room to work from the outside. What will happen then is concrete people will come in and form up what’s called your footing. Now, they use something typically called forma drain or just rigid frames but for our purposes, we are going to assume that they are using forma drain system, which is a part of sump pump system. So, the foundation is poured and that has dry for a number of days. They want that to harden up real good.
Then the concrete people are going to come in and set forms, which are going to be 8 feet tall and are separated by about 8”, the thickness of the wall. They are also going to place metal rods in the concrete. The metal bars run in the concrete and into the footing to help secure the wall to the footing. That way, when you put dirt back alongside the wall, it can’t actually cave in.
A day after they pour the wall, they will strip out the forms from the wall. Your wall will have to cure for about a week or ten days. In the end, they are going to come in and fill up the outside of the hole as well as the area on the inside where they have dug a little deeper to get down to the bottom of the footing. In some cases, they will only dig a foot little deeper and leave the remaining all dirt.
The better excavators will always dig all the way to bottom of footing on the interior of the basement and then they put in what they call Engineer Fill or Stone. Engineered stone or fill will not settle and that will allow the home to sit on something real solid. Also, when they use these types of systems, if any water were to ever penetrate underneath the home, it will flow over to the drain tile, which will bring water out of the house before it becomes a problem.
On top of the filling stone, they are going to put a plastic vapor barrier, which is simply there so any moisture doesn’t move up into the concrete from the area underneath the concrete floor. Then, they will pour a concrete floor typically 3-4”. Most builders are going to have your concrete completely finished and your concrete floor installed before they start framing the home.