Building a Garage Foundation: Mistakes to Avoid

Building a garage foundation can be a big undertaking, but it is something that can be done by the homeowner. Take advantage of free online resources and research the project before attempting to build the foundation. The benefits of researching are that you can learn from other people and you will not make the same mistakes that others have made. You will have a good idea of how long the project will take, what tools are needed, and a complete and accurate list of supplies.

Notify Authorities

One of the most common mistakes that occur when building a garage foundation is that the homeowner did not notify the town or city authorities to obtain the necessary permits. When permits are not obtained, the town can stop the process of the project, or even require the structure to be torn down. This is a huge waste of time, money, and patience. Most towns and cities will have building regulations and codes that must be met, and will be provided when obtaining the permits. If the building codes are not met, the city can tear down the entire building. The town will also tell you if there are any electrical, gas, or cable lines in the ground in the area that the garage will be built.

Deep Walls

Another common mistake is that the foundation walls do not go deep enough into the ground. The foundation could sink deeper over time and cause a lot of expensive structural issues in the future. If this garage is going to have a car or heavy equipment inside, be sure the foundation is deep enough. The concrete also has to be thick enough to support the garage and keep the water out. The garage foundation must be perfectly flat or all measurements will be off and the garage will be crooked.

Proper Planning

Consider the need for drainage, electrical outlets, plumbing, and HVAC prior to pouring a concrete garage foundation. These must all be planned for and done exactly right, because everything will literally be set in stone. Then, make sure the concrete foundation has been cured before you start to build on it. Foundation vents might also be required, depending on where you live. The vents are needed for various reasons, especially to allow the air to move so that any moisture will dry. Without vents, the garage foundation can become moist, which will inhibit the growth of mold and mildew and will break down the concrete.

Things to Remember

There are a few more things to remember when building a garage foundation. Make sure you dig a few extra inches around the slab when digging holes for the footings to allow room for the vapor/sand barrier. The rebar should be between 2 and 3 inches away from the ground, on all sides, when running it horizontally along the bottom of the footings. Put the foundation bolts into place before the concrete hardens, which will be used later to hold sill plates. Don’t forget to use an oil spray on the concrete form boards so it will be easer to remove the boards once the concrete foundation hardens.