San Antonio, Texas is the seventh largest city in the United States and its soil conditions create many problems that will require foundation repair. Because of the lack of any significant population surrounding the city limits, the San Antonio metropolitan area is ranked 28th in size in the United States. The 2007 population of San Antonio was estimated at 1.3 million and the metropolitan statistical area (MSA) placed its population at 2 million. Overall, San Antonio has a relatively high degree of soil instability, making home foundation repair problems and concrete slab repair leveling fairly common.
For more information about Foundation Repair in San Antonio, Texas, see the following:
· Request a FREE*, no obligation foundation inspection in San Antonio, Texas.
· Browse the foundation repair methods commonly used in San Antonio, Texas.
· See a step-by-step walkthrough of the foundation repair process.
San Antonio Soil Characteristics As They Affect Foundation Repair
San Antonio has a total area of 412.07 square miles (1,067.3 km²) – 407.56 square miles (1,055.6 km2) of land and 4.51 square miles (11.7 km2) of water. The city sits on the Balcones Escarpment, which forms the eastern boundary of the Texas Hill Country and the western boundary of the Texas Coastal Plain. San Antonio area soils are composed of stratified loam, clay, and sand. There are scattered rocky areas throughout the area.
The Bexar County and San Antonio areas are represented by three different geological periods: The Cretaceous, the Tertiary and the Pleistocene. The oldest is the Cretaceous (Upper and Lower) and it underlies the others. The Upper Cretaceous is characterized by rocks of pure white limestone and chalk and the limestone is so soft that it can be cut or sawed into blocks for building purposes. The Tertiary period is primarily characterized by ferruginous sands, sandy clays, and impure marls. The Pleistocene period is characterized by deposits of flint gravel with some limestone gravel, both of which are embedded in a matrix of chalky material. Often a firm conglomerate is formed from the “cementing” of the gravel and the chalky matrix.
The United States Department of Agriculture, Natural Resources Conservation Service issued an extensive report about the soils in Bexar County and the San Antonio area. Engineers and other technically inclined individuals may want to read the report in full. One part of particular interest, however, appears on page 109 of the report:
FoundationsBexar County has large areas of clay soils in which the clay mineral montmorillonite is abundant. Such soils are poor materials in which to set building foundations. They swell when wet then shrink and crack when dry, and in so doing they exert such pressure that walls and foundations will crack unless, and sometimes even if, specially reinforced (fig. 31 and fig. 32). The soils most likely to cause damage are the Houston clays, the Houston Black clays, Crawford clay, and the Lewisville silty clays. Plasticity index and swell index indicate whether a soil is likely to shrink and swell enough to damage foundations. Several soil samples furnished by the Soil Conservation Service were tested on the FHA’s “potential volume change” meter. Table 6 shows the swell index of each of the samples, as determined by the tests, and the plasticity index, determined from the swell index.
The characteristics of the soil present homeowners with challenges of house foundation repair in San Antonio, Texas. This swelling and shrinking of the soil will crack concrete slabs and concrete home foundations in San Antonio, Texas. Click the following link to learn more about the technical and engineering aspects of house foundation repair in San Antonio, Texas.
Climate Influences On Home Foundation Repair In San Antonio Texas
Bexar County and the San Antonio area have a modified subtropical climate with hot summers and mild to cool winters. The falls and springs are comfortably warm and rainy. The hottest months for the area, July and August, have an average high of 95°F (35°C). The highest summer temperature ever recorded was 111 °F (43.8 °C) on September 5, 2000. The average coolest month is January with an average low temperature of 39 °F. Rainfall is fairly well distributed throughout the year with an annual average of 29 inches. The month of May has the highest average monthly rainfall of 4.2 inches.
If you would like to take a detailed look of the soil in your neighborhood, consider looking at the United States Department of Agriculture’s Soil Survey Tool. It will give you an in-depth look at exactly what type of soil your home sits on and the characteristics one can expect from soils of that type. For your convenience, you may utilize a tutorial on how to use the Soil Survey Tool that we have compiled.
Service Areas For Home Foundation Repair In San Antonio Texas
Dawson Foundation Repair will provide FREE* home foundation repair inspections and estimates for the San Antonio, TX area.
*for homes NOT involved in real estate transactions