Many homeowners usually don’t think about how the soil around and underneath their house can affect the foundation, but many problems can derive from different soil conditions. Whether this involves soil types, soil preparations before building or soil changes that have taken place, the cause of many foundation problems stems from, well, dirt.
How Soil and Foundations are Related
If you were to ask someone why a home’s foundation is important, the reply would probably be some variation on “It provides a base for the house, and having a sturdy base is important.” And they would be correct. So why is the soil that your home is built upon so important? Well, in part because it serves the same function for your foundation as your foundation does for the rest of the house. It is the base upon which the foundation rests.
And if the soil can’t provide a sturdy base for the foundation, you will need to find something that can. Otherwise the foundation won’t be able to do its job.
What Different Soil Types Mean For Foundations
Clay Soil
Clay soils are also sometimes referred to as “active soils” or “expansive soils” because of their extreme shrink-swell cycles. The minerals that make up clay soils are chemically capable of attracting water molecules, holding the molecules between their layers. These water molecules then cause the soil to expand.
This expansion can cause foundation problems in a few ways.
- Heaving: If a portion of the soil beneath your foundation begins to heave, it can strain the foundation, causing cracking and throwing portions of the house out of alignment.
- Pressure on Foundation Walls: If you have a basement foundation, the slab isn’t the only part of the foundation that can feel the effects of clay soils. The expansion can press outward as well as up, putting pressure on the foundation walls. This can cause them to crack and either bow inward at the cracking point or lean.
- Settlement: One of the ways that some choose to fix clay’s tendency to heave is to wet the clay so that the structure is built on soil that is at the peak of its swell cycle. While it might solve the heaving problem initially, if steps such as underpinning aren’t taken, as soon as the soil dries, the shrinking will likely bring foundation settlement, where the foundation begins to sink into the dryer soil.
People try various means when they have a house built upon clay soils, from chemical treatments to using drainage, vegetation and other means to attempt to keep a relatively stable soil moisture content around the foundation.
At Jerry’s Waterproofing, we can install drainage systems that can deter the worst of the swelling around your foundation. We can also install foundation underpinning through helical or push piers that extend beyond the clay layer to a level of soil able to consistently support the weight of your home. We can also install anchors to deal with any bowing of basement walls caused by the pressure exerted upon them by the clay soil.
Sandy Soil
Sandy soils tend to be less troublesome than clay. They have far superior drainage and don’t have the same shrink-swell cycles.
They can run into problems in two places: compaction and erosion.
First, if the sandy soil isn’t properly compacted, the soil is likely to be compressed by the weight of the home. Most homes settle slightly because of their weight, but significant amounts of settlement (especially uneven or differential settlement) can bring significant foundation problems.
Second, sandy soils are prone to erosion. If water begins to erode the soil around your foundation, it can weaken the support it is receiving.
Silty Soil
Silt is generally considered among the weaker soils. It has some of the moisture retention properties of clay, but is generally isn’t as difficult to work with. It isn’t as course as sand, but still can run into erosion issues.
Loam Soil
Loam isn’t so much a distinct soil as it is a mixture of the above three types. As such it is both considered the best soil for building upon but also highly dependent upon the mixture of clay, sand and silt. Some of the weaknesses of the most dominant component can still show through.
How to Fix Soil Problems
The moment you suspect foundation problems, it’s essential that you call a foundation professional. Though it may seem like shrinking and swelling dirt may be an unsolvable problem, Jerry’s Waterproofing can solve all your foundation issues.
Foundation problems can tend to be scary. Leaving foundation problems unsolved can be dangerous and pricey, but these problems are not unmanageable. If you suspect that your foundation is in bad shape, don’t hesitate to contact us for a free estimate.