Expansive clay soils are present in lots of areas of the country, including Texas. This kind of soil shrinks and cracks when it dries out. When it rains, soils with high clay and silt content don’t allow water to pass through the soil. Instead, water is absorbed and held in the soil, significantly increasing its volume.
Soil and water pressure could cause foundation problems
It’s difficult to imagine that soil can harm a material as hard, dense and strong as concrete, but homeowners and foundation repair contractors alike will testify to the destructive power of expansive soils.
So what type of damage can occur because of expansive soils, and how can it be repaired and/or avoided?
Cracked and buckled walls probably occur more frequently because of expansive soils than other foundation problems. During a dried spell, clay-rich soil is likely to distance themself from a basis wall, creating a difference that may fill with stone, gravel, loose soil and other debris. Some homeowners even deliberately complete this shrinkage gap losa de cimentación proceso. Nothing bad happens until there’s a long, soaking rain. Then the extra material in the crack increases pressure on the foundation wall since the soil expands. Since there’s not just a balancing volume of expansive soil against the within of the wall, this one-sided pressure can push the wall inward, causing it to crack and bow in sections. Occasionally the building blocks wall will resist cracking or bowing, but the damage will take the shape of tilting. The top of the wall is likely to be pushed in by the expansive soil, creating a basis that tilts inward.
Soil that shrinks, settles and expands causes slabs, footings and walls to crack
Other site conditions that may donate to foundation problems concerning expansive soils include trees and bushes that displace soil or increase drying and shrinkage by absorbing ground water. Soils rich in clay and silt aren’t just unstable; they likewise have poor load-bearing characteristics compared to soils which contain sand and gravel. Foundation footings and slabs built on clay-rich soil can heave in a reaction to wet conditions or settle because of excessive shrinkage. In either case, cracks in foundation slabs, footings and walls will probably accompany heaving and settlement, since concrete can’t stretch or bend.
Foundation repair contractors overcome soil problems with special tools, materials and techniques
To a homeowner, the kind of foundation damage stated earlier looks severe. But an experienced foundation repair contractor sees a chance to stabilize difficult soil and connect the building foundation to solid, stable soil at greater depth.
Different techniques can be used stabilize the soil that surrounds a home or commercial building. Since water is what makes clay-rich soil swell and shrink, one of many first things foundation repair contractors do is to check the function of gutters, downspouts and general drainage round the house. Moving water away from the building blocks is just a reliable way to limit soil movement, protecting the building blocks from soil’s expansive pressure.
If the soil has shrunk or settled, causing the masonry to crack and sink, soil stabilization may also be attained by driving helical piers to the soil. The helical flanges (or plates) on these steel piers are shaped just like the threads on a wood screw, and function in a similar way. As the contractor turns the shank of the pier, the helical plates pull the pier deeper to the soil. The contractor could add pier sections to be able to reach stable soil underneath the damaged foundation. When the pier’s resistance to rotation reaches a predetermined level, the contractor knows that the pier is solidly anchored, and can offer the stable support the building blocks has been lacking. A bracket is installed to connect the pier to the building blocks; this could also enable the contractor to lift a sunken slab, footing or wall back once again to its original position.