How to Lay Out a Concrete Foundation

The concrete foundation is the most important part of any building. It is a solid base which will support the whole weight of your building. Any weaknesses in the concrete foundation will cause problems for the entire structure. This article details the steps you follow to build a foundation that won't let you down.

Step 1 - Plan the Concrete Foundation

Decide on the size and thickness of the foundation. The dimensions will mainly depend upon the type of structure you are building and the land that you are building on. Make sure the concrete slab is thick enough to provide support to the entire building and that there aren't any weaknesses which could later pose a problem.

Step 2 - Dig the Trench

After you determine the size and thickness of the concrete foundation you need, you can start digging the trench. Dig the trench twice the depth of the concrete slab you will pour. If you see any stones or pieces of trash in the hole, remove them now.

Step 3  - Prepare the Trench

Next you need to prepare the trench by adding some sand at the bottom and placing a membrane over the top. This technique will help to prevent any damage caused by water.

Step 4 - Make the Frame

You will now need to construct a frame out of wood. You will use the frame to contain the concrete while it is still a liquid. A frame is easy to make, and it should be even easier if you make it in place.

Use stakes to hold the frame in place. Make sure that none of the liquid will be able to escape anywhere. You will also need extra pieces of wood to use as screeding bars, which will ensure that the concrete is smooth and level.

Step 5 - Mix the Concrete

It's now time to mix the concrete. You can mix cement by hand, but you probably won't want to do so for the amount of cement you'll need for the foundation. Instead, either hire a cement mixer or purchase ready-mixed concrete, which can be poured directly into your hole from the big cement-mixing truck.

Step 6 - Level the Concrete

Use the screed bars to level the concrete in the hole. Then allow the whole thing to dry.

You should be left with a completely level concrete slab of the exact dimensions required. If you encounter any high or low patches, you can  sand these off with an electric sander. If you find any holes in the concrete foundation, use a self-leveling compound to smooth these out.Do not use a very thin layer of concrete because this will chip away very easily.