The main reason is the soil conditions in The Houston Texas areas. The soil in Houston is very expansive. So when it rains or gets wet the soil expands and can cause the soil to heave putting enormous pressure on foundations. if you live in Houston you know that the summer is very dry and hot. During the dry summer conditions these clay expansive soils will shrink and can cause large voids which can lead to foundation settlement. Fluctuations of the soil is your foundations enemy. So dry and wet conditions will cause the fluctuation that can cause damage to your foundation. If home owners in Houston know that controlling the moisture level of the soil could avoid foundation issues than there would be far less foundation problems in the Houston areas. a watering program can be very valuable in our area. Watering the foundation during the the dry summer months and not watering during the wet month. There is a certain watering program you should follow and look for the advice of a Licensed P.E.
Let’s start out with one of the most important parts of your home that rarely gets noticed by home owners until there are problems. This is a reason it is so important to have a home inspection or annual inspections done to ketch conditions that can contribute to foundation failures. There are many conditions that can contribute to foundation issues from poor drainage to expanding and contracting soil that is present in the Houston area to poor building practices. On slab foundations corner pops or cracks at the corner of the foundation are common and are present at many older and newer homes if sealed and maintained these are not a Hugh concern. Many times there are hairline cracks visible at the exterior of the foundation, without any serious signs of deflection. These hairline cracks will need to be monitored over time. Then there are the more serious separating cracks where there are signs of deflection of the foundation. If serious deflection is observed at a home inspection I will recommend further evaluation by a structural engineer. This will give the client a better idea of how extensive and serious the problem may or may not be. A common problem with post tension foundations is that the tension cables become exposed and if left unchecked this can become more serious. When the post tension cables are exposed to the elements they rust and can break under the tremendous tension. This can cause serious damaged to your foundation. I recommend having these repaired if observed at a home inspection. They will need to be cleaned, and have an anti oxidant grease applied and also covered with a non shrink grout. Pier and beam foundation sit above the grade. Some of the issues with these can be poor construction, settlement over the years, damaged and moisture damage beams twisting beams, beams not resting properly on piers, and termite damage, Piers installed improperly or not in enough area to support the structure properly, damaged piers, and leaning piers, and many more defects can be present. All of these issues can be serious . I would recommend consulting with a structural engineer for a watering program for your foundation this can keep your foundation going strong for years.