One year after Hurricane Harvey many of the homes that rest on pier and beam foundations are displaying significant damage. Most of these homes were built before the 1960s and usually the first sign of a foundation problem is with the floors. If the underlying concrete pads and blocks have moved up or down then the floors can buckle, crack, or warp. Other foundation warning signs are cracks in the interior walls, usually around doors and windows.
“What happened was that many areas of Houston were flooded for two or three weeks or longer. The clay soils that are several feet below the surface became saturated with water and expanded in volume. The clay soils are not distributed uniformly, either laterally or vertically. The result is that some areas of the soil under homes expanded more dramatically than other areas. The uneven expansion resulted in uneven upheaval of the home or structure. Now that we have had three or four months of hot summer weather most of that excess water has either filtered to lower soil levels or evaporated and the same clay soils have experienced dramatic shrinkage in volume. This is called settlement. The concrete pads and blocks will ‘settle’ at a lower elevation than one year earlier because the expansion and contraction has further compacted the soil,” explained Mr. Dawson.
Generally pier and beam foundations are more expensive to construct than concrete slab foundations and that explains why most homes built since the 1960s are built upon a concrete slab. However Houston experienced three consecutive 500 year floods in 2015, 2016 and 2017 and city officials recognize the need for better flood control management. Part of the flood control issue is reducing or minimizing the concrete and asphalt footprint of roads and buildings. Therefore there is an effort to require home builders to build on pier and beam foundations, which allow the soil under the house to absorb some water during heavy rains.
Dawson Foundation Repair
6906 Chetwood Dr, Houston, TX 77081