Understanding why you may have Foundation Problems with your Concrete Slab Foundation
There are several reasons why a concrete slab foundation could fail. It is important to both 1) Identify the CAUSE of your problem and also 2) FIX THE DAMAGE that has resulted. Common reasons for problems include:
1) Underlying Soil
Seasonal conditions cause the soil properties to change. When soil is full of water it naturally swells. When it dries out it contracts. The process over time undermines the integrity of the soil, and any foundation built on it. On the East Coast, namely Virginia Beach, and the Hampton Roads area, clay soils are the predominant soil type. Clay soils are the worst draining of all soil types causing a higher proportion of foundation issues.
2) Faulty Construction Methods
The soil should be prepped prior to the pouring of any concrete. For a highly clay soil like that of Virginia Beach, sand should be added to facilitate drainage. Foundation contractors should also tamp the soil with a tamper prior to ensure the soil is compact as possible to reduce the chance of any settling. The soil should be even before pouring any concrete. Additionally the use of rebar and fibers can be used to further strengthen the concrete footings.
The building codes in Virginia Beach, Norfolk, and Chesapeake were much more relaxed in the past than they are now. Many homes in the Hampton Roads area were built in the 1960's - 1980's. Contractors could get away with pouring concrete without doing the proper prepwork including proper backfill, rebar, and concrete wire. Some concrete foundations were poured too thin to save money on concrete.
3) Improper drainage
Water is your friend when you are drinking it or when you are taking a shower, but it is your enemy if it gets under your home. In some cases, busted plumbing under the soil compromises the soil and the foundation. Most commonly, the yard doesn't have proper drainage. The ground surrounding your home should be graded/sloped away from your home to allow the water to drain. If the water is pooling around and under your home, you have a problem you need to fix immediately before the damage is done.