Why so many Foundation Repair Companies in North Texas?
The reason foundations are a real issue in this area, let me explain. 250 million years ago, during the Permian period, the beautiful land of north Texas lay beneath the waves of a vast tropical ocean teeming with life, as time passed the waters receded leaving behind a swampy mess then drying and becoming the prairie we live on today. Evidence of the life before can be found where rocky hills are cut for our highways. From the primordial matter of yesteryear, large deposits of usterts veristol are prominent in North Texas. Okay I lost you all. Veristol is a soil with a high content of expansive clay. Usterts is the type of clay which leaves exposed cracks for at least 90 cumulative days in a year. During the rainy seasons of fall and spring the clay absorbs the moisture swelling in size only to shrink again under the scorching Texas sun. Early builders in north Texas were aware of the local conditions. The earliest developments used stable land to build. As time passed and developments grew, those areas began to disappear, unfortunately recent builders use the parcels left over to construct homes. The clay in north Texas also has a high plasticity which makes it the second worst type of soil for construction. The worst is high organic peat such as you would find in swampy areas, like southern Louisiana for instance.
The second ingredient is the foundation itself. Concrete is a material which had been used by the Romans. The same basic materials are used today, aggregate and a binder mixed with water. Of course the process of making concrete has changed over the years, chemical additives such as accelerators, plasticizers and retarders are now used as well as blended cements and mineral admixtures. Concrete has a very high compressive strength. Compressive strength is a pushing strength, crumpling a piece of paper in your hand and crunching a can under your foot are examples of compression. However for all of the compressive strength, concrete is very weak when in it comes to tensile strength, when you think of tensile, think of pulling, like ripping off a hunk of French bread or dragging a toy wagon. Steel (re-bar) is added to the concrete to increase the tensile strength thus reinforced concrete. Now that is all out-of-the-way, let’s dig into the nuts and bolts of foundation problems.
In north Texas homes we typically have two types of foundations. Pier and beam and slab on grade. Pier and beam foundations are found in historic homes as well as high-end homes. These foundations consist of wooden or concrete piers extended into the ground below frost depth and are spaced along the perimeter and interior of the home. Wooden floor beams and joists are used to support the floor of the home. Pier and beam foundations perform very well with expansive clay soils however other problems exist. The wood that supports the floor can deteriorate or become infested with termites causing the floor to sag. Piers can settle unevenly again causing interior cracks and other problems. The expense of the design and construction of pier and beam can make a home unobtainable for the average buyer. Most of the homes in our area consist of slab on grade. Slab on grade is an inexpensive way to build multiple homes. Shallow frost depth make slab on grade construction possible in north Texas. Slab on grade is simply concrete poured over re-bar usually six inches thick at the perimeter and four inches towards the center. The slab sits on the soil. The earth beneath the slab absorbs moisture then dries. The clay beneath expands and contracts. Sometimes the slab sits entirely on the clay sometimes only on pockets of clay. During rains, the water permeates into the soil at the perimeter of the foundation and seeps towards the center, creating uneven expansion. A portion of the slab will lift while another portion stays flat, causing tensile stress within the concrete slab. In extreme situations the slab itself can crack. In most situations it causes cracks above doorways and windows, doors sticking within the frames, cracks in masonry walls, molding pulling away from walls, cracks in tile floors and uneven floors. This is perhaps the biggest issue for homes in north Texas. Sometimes roots from nearby trees will cause foundation problems with the same results however in most cases the expansive soils are to blame. This is the reason for so many foundation repair companies. Older homes are generally built on soil with less clay content. Watering around the perimeter can help the situation but it is not a cure-all. With the drought conditions in north Texas, foundation problems are a real issue. If you do suspect foundation problems then by all means contact a specialist. Be sure however to get multiple opinions and bids for the work. Foundation repair is expensive. In some cases it may be worth hiring an independent structural engineer to determine the problems and to plan the repairs, then hiring the repair company. Repairs usually consist of drilling piers beneath the affected areas to stabilize the slab. However methods do vary depending on the company. Buyers must be aware of the signs of foundation issues while touring homes. Sellers and Owners must also keep a look out to keep the value of their homes from declining. See ya down the road.