Several factors cause foundation damage in Huntsville. These range from weather to soil causes, hydrostatic pressure, tree root invasion, and more.
Excess Precipitation
Huntsville’s climate is characterized by hot summers and short but cold winters. Rain is quite plentiful during winter and spring, but generally, the city receives significant amounts of rain, even during the driest months.
High amounts of precipitation are a leading cause of foundation problems, mainly due to the nature of Huntsville soils. The city sits on the Tennessee River Valley, flanked by a chain of mountains, namely Round Top, Huntsville, Wade, and Madkin. These mountains are capped with sandstone, but the valley itself is underlain with limestone. Essentially, the soils in Huntsville have evolved from bedrock weathering and are mainly alluvial, composed of sand, silt, and clay.
In areas where the clay concentration is high, soil expansion is prevalent. Usually, clay doesn’t allow water to flow through. Instead, it absorbs it, leading to expansion. When it expands, the movement may affect the foundation, causing it to heave and crack.
The situation is made worse if the landscape surrounding the house has poor drainage. For this reason, builders often recommend a combination of different types of drainage systems such as French drains, downspouts, catch basins, and such, to help channel as much water as possible away from the building.
Tectonic Activity
Earthquakes, though mild, are pretty frequent in Huntsville and happen to be responsible for some of the foundation repairs we perform. These constant earth movements wreak havoc on the structural integrity of buildings. Though they may not have a sudden effect, the tremors, however mild, may finally cause differential settlement, especially if other triggers are present. Essentially, differential movement occurs when one part of the foundation moves while the other remains intact.
As such, raft and pile foundations are normally recommended to minimize the occurrence of differential settlement. A combination of steel and concrete also helps in strengthening the foundation, to mitigate the risk of damage.
Poorly Compacted Soils
When laying the foundation, sometimes builders use fill dirt or fill soil to level the site. If the native and the foreign soils have varying properties, they may react differently under the building’s weight or when water seeps in. This may lead to the type of foundation movement we have mentioned above: differential settlement.
Even where the builders use a similar fill soil, issues may still arise if the soil is poorly compacted. In that case, differential, tilting, or uniform settlement may occur, depending on whether the soil is uniformly compacted or some parts are looser than others. With tilting settlement, the foundation tilts towards one side, while uniform settlement involves the settling of the entire foundation.
Hydrostatic Pressure
Hydrostatic pressure is the force standing water exerts on the surroundings. If the building stands on a poorly-drained area, rainwater or water from irrigation may pool under the foundation. That’s why the heavy downpours that often rock Huntsville from time to time pause a threat to foundations.
Even where soils are reasonably drained, too much water raises the groundwater levels which then exerts pressure on the foundation and basement walls, thereby causing movement. When that happens, basement leaking, cracked or bowed walls, increased humidity, and mold growth, to name a few, often arise.
Invasive Tree Roots
Many Huntsville residents love the aesthetic appeal our native trees add to their landscapes. It’s not uncommon to see tree canopies surrounding homesteads. Besides, they provide a shading effect, shielding buildings from harsh sun rays. Trees also act as windbreaks, keeping roofs from being blown off by strong winds. However, despite the numerous benefits they offer, some tree species cause devastating effects on foundations.
As they spread out their roots for support, water, and nutrients, they sometimes crack the plumbing, leading to water leaks. When the water pools together, it exerts hydrostatic pressure on the foundation and basement walls, as explained above.
Once the foundation cracks, the tree roots may penetrate through the crevices. As they grow in and expand in size, they can even cause the building to crumble.
Deep Root Decay
Foundation movements related to organic substance decay often occur in areas where land developers cleared trees to construct buildings. If some roots were left underneath, they decompose over time, causing the soil to shift downwards. Movement in the soil may result in foundation settlement at that particular spot, leading to cracks.