The foundation of a house is a structure on which a house sits. In some instances, the foundation of a house rests on footings and supports the rest of the flooring. This is the same case to conventional piers and foundation walls. In other cases, a foundation also doubles up as the footing — similar to a home built on ground-lodged piles. In the case of the monolithic slab, the floor system, foundation and footing are one. Whichever system you choose to go with, it is critical that you think your choice through, as foundations can be quite costly.
Some homeowners believe that a foundation that leaves a crawl space beneath it is the most desirable. The crawl space has to have an 18×24 inch access door. The space has to have ventilation allowances to the tune of one square foot per 150 square feet of crawl space. Others believe that a wooden floor has a live feel to it and that it is warmer than a slab. However, with proper insulation, a slab can be just as warm. There are several types of home foundations. They include:
Masonry foundations
According to the National Home Builders Association (NHBA), masonry foundations are quite popular in the United States. This foundation system consists of a masonry perimeter wall (concrete or brick) sitting atop a concrete footing.
Concrete foundations
These are also quite popular and especially where the homeowner intends to have a basement. The foundation consists of metal or wood forms set on footings, rebars or reinforcing steel bars for wall strengthening and anchor bolts for securing exterior walls. Lots with active or expansive walls require the installation of a caisson foundation system.
Wood foundations
This system has several advantages. Firstly, there is no need for masons, secondly, the system is fast and thirdly, it is possible to erect the foundation even in the worst of weather conditions.
Pile house foundations
Usually common in beach houses. This foundation is ideal for soils that are unable to support the entire weight of the house.
Generally, a house foundation consists of the following:
Excavation
Anticipated size of the house and associated loads determine the depth of the excavation.
Reinforcement
Size and load of the structure once again determines the reinforced steel bar mesh size.
Concrete
Fills up the trench and spreads over the reinforcing mesh. Tamping of the concrete then follows to eliminate trapped air that might cause structural instability.
Block work
This brings the construction to a suitable level, while maintaining a strong structure.
There is no standard depth for foundations. This is because the depth depends on the size and associated loads of a structure. Calculations done during the design phase determine the depth of a foundation. Every kind of structure has to have a foundation. A well-built foundation would be able to support the weight of a structure without failing or cracking.
Jess Lavines is a freelance writer who has wroked in construction for 6 years. Jess has been doing some writing for a company that does basement excavation, and hopes to start writing instructional books for home renovation topics such as foundation work or interior design.