Types of Foundations

There are several different types of foundations that can be used when building a new residential or commercial structure.  However, there are 3 primary types that are most common; Slab foundations, crawl space foundations, and basement foundations.

Slab Foundations are definitely the most common of the foundation types primarily because of the low cost associated with it.  There are other benefits such as energy and weather efficiencies, but the main factor is speed and price.  The slab foundation is started by first pouring a stem wall that outlines the load bearing footprint of the structure.  The  stem wall must be built deeper than the frost line of the land and typically even with the surrounding grade of the property.  Once the stem wall is poured, any plumbing or mechanical equipment will be laid in place, then a filler will be add, such as sand, then approximately 4 to 12 inches of concrete slab is poured.  Speed, cost, and efficiency are some of the main benefits o a slab foundation.  However, slabs do have a down side.  For example, if there is a plumbing or mechanical issue under the slab, it can be expensive to repair.  Also, the slab foundation put the property at ground level which makes it more susceptible to weather and flooding.

Crawl Space Foundations were very popular and mostly used up until the mid 1960's.  Like the slab foundation, the crawl space also utilizes a stem wall for the load bearing footprint.  Then, most crawl space foundations are made up of a pier and beam system where concrete piers are installed in various locations underneath the house and wood or concrete beams are run from pier to pier providing it's support for the house.  This foundation system has some benefits in the  accessibility it provides to the mechanics under the house, such as plumbing or heating and air ducts.  It is also easier to repair or adjust if there are any shifting issues.  The disadvantages would be that it can hold moisture under the house causing long term issues.  It also lets hot or cold air under the house which can cause it to be more difficult to control the temperature inside the house.

Basement Foundations are common in many parts of the country, but much less common in Oklahoma.  The only time you'll see consecutive houses with basements is in neighborhoods build in the 20's and 30's.  How-a-days, they are far less common due to the added cost associated with basements.  Most areas of the country that still build homes with basements are in the northeast or in colder areas, where the front line is deeper in the ground.  Since home builders are required to build foundations below the frost line it makes sense to just add a basement is your'e already having to dig 8 feet deep.  Basements are great for added storage or even extra living area is they are finished out.  However, over time they can cause more issues if not properly maintained.  Since a basement is below ground it is more prone to moisture issues such as flooding and mold growth.