A slab foundation is simply a slab of poured concrete on which a house is built. A slab foundation generally sits on top of a foundation that has been built below the frost line. The concrete slab is typically 4 to 8 inches thick with embedded steel rods known as “rebar” to prevent cracking and failure. The foundation of the house is built directly on the ground with no basement or cellar. All water lines and beltlines are installed prior to pouring the concrete.
ADVANTAGES OF THE SLAB FOUNDATION
One of the main reasons why slab foundations are popular is the cost factor. Slab foundations are the least expensive and the fastest to install. Slab foundations reduce the cost of the entire building simply because the houses are built directly on the slab. That saves the cost of the floor joists that would normally support the building. Homes with a slab foundation are easier to heat because there is no air space under the home to affect indoor temperatures.
DISADVANTAGES OF THE LOSA FOUNDATION
Because there is no basement or basement, all vents must be routed through the attic and through wall gaps. There is no additional space for utilities or storage, the entire house is basically sitting on a large solid concrete platform. Although slab foundations are the least expensive home foundation to build, they are the most expensive to repair. All of the plumbing in the house is basically under the concrete slab, making it impossible to repair without breaking the concrete floor that is now part of the interior of your house. Leaks are difficult to detect because they are below the slab, and in many cases go undetected for years. An unusually high water bill is the first indication that you may have an underground leak.
THE SECOND OF THE THREE TYPES OF HOUSE FOUNDATIONS-CRAWLSPACE
The Crawlspace foundation consists of a concrete perimeter wall and concrete columns that will support the floor joists of your home. The distance between the ground and the first floor of your home is known as the crawl space. This foundation is built at grade level or over a shallow excavation depth of 3 to 4 feet. The exterior foundation walls will bear the load of the building and several concrete piers will be built in the mezzanine for additional support. Crawl space foundations in the past have been built using the original soil as a floor, and recent building code changes now insist that at least a two-inch cement floor be used to help control any moisture problems. .
CRAWL SPACE ADVANTAGES
A Crawlspace foundation raises the house 3 to 4 feet above ground level. This has many advantages, all plumbing, wiring and ventilation ducts can be easily maintained and repaired. In addition to providing access under the house, crawl spaces allow airflow under the house. This will help cool down in the summer, crawl spaces are usually cool when well ventilated.
Crawlspace House Foundations in floodplains
If you live in an area that is prone to flooding, having a crawlspace foundation is a blessing. By installing foundation vents, you can reduce the chance of structural damage to your foundation. Vents when properly installed will allow water to flow under the home, reducing the amount of pressure a normal foundation would experience in a flood. Vents are designed to allow water to flow in and out without damaging the foundation. Vents are so important that the Federal Emergency Management Association (FEMA) has made the installation of Type A vents mandatory in flood prone areas.
DISADVANTAGES OF THE CRAWLSPACE
The cooling effect that the house experiences during the summer can freeze the house in the winter. The floor joists in the mezzanine must be highly insulated, which will increase the cost of construction. Water can pool under your home and provide an ideal nesting area for insects. The most concerning disadvantage occurs only if these foundations are not properly maintained or are built without adequate ventilation. Fortunately, flood and vent technology has eliminated many of the moisture and mold problems of the past.
THE THIRD TYPE OF HOUSE FOUNDATION – BASEMENT
The basement is a typical home foundation that includes an entire living space below the first floor of your home. In addition to providing additional living space, the basement provides easy access to all of the home’s utilities. Basement foundations start with a sub-grade below the frost line and then concrete walls are erected approximately 8 feet above the sub-grade, a concrete slab is used for the basement floor. Basement foundations have the advantage of providing excellent storage space and a clean, dry space for all utilities. Many times entire foundations have been converted into apartments that can be rented out and provide additional income for the owner. Whenever a basement is converted to an apartment, at least one egress window must be provided.
Disadvantages of the basement house foundation
The main disadvantage of the basement is that because a good part of it is below grade, they are susceptible to leaks and mold growth. In areas with a high water table, a secondary pump may be installed to combat flooding. Basement house foundations are the most expensive to build because of all the extra material needed and time to build it. However, this additional expense during construction will make your home easier to maintain. A home with a full basement generally has a higher resale value than any of the previous types of home foundations mentioned.