Most people think of floods and heavy rainstorms wreaking havoc on your foundation. But, a hot dry summer can do its damage, too.
What happens is that during a hot, dry summer the soil contracts beneath the foundation and causes the foundation to crack and sink. Once the rain comes again the cracked foundation starts leaking.
This phenomenon happens most commonly in clay and expansive soils. Clay soils shrink during droughts and expand during floods and rainy seasons causing structures to move. Sandy soils lose its adhesive properties in dry conditions and pulls away from the foundations. Heavy rains are more disastrous with sandy soils because the soil shifts or collapses beneath foundations. Sandy and clay soils both experience sinking issues. In engineering terms it is called subsidence. Usually this process happens gradually over time; however, with extreme climate swings it can accelerate the effect. That is why you see issues happening over a course of a summer.
Signs of Damage
The most common signs of subsidence are cracks in the foundation wall, bowing walls, grout popping, or tile breaking. Other signs of foundation failure are windows and doors not closing properly, chimneys or porches separating from the house, and bowing basement walls.
If you are shopping for a house over 10 years old, watch for patched over cracks in brick or drywall or planed doors. Also watch for cracks in the sidewalks and streets in the neighborhood. In newer homes it is harder to know if the home could withstand shifting soil. If you are in a more problematic area like the southwest, southeast, Midwest or coastal states, it may be a good idea to consult a geotechnical engineer to do a soil assessment.
Fixing a Broken Foundation
There are many techniques to fixing a broken foundation and stabilizing a foundation on unstable soil. If the soil is sinking and shifting it will continue to have problems in the future. The more you ignore the issues the bigger the problem becomes. If you don’t take care of the issue, the worst case scenario would be a collapsed foundation.
Fixing this issue usually involves hiring a structural repair or foundation repair contractor. They will most likely install some sort of piering or underpinning system underneath the house to shore it up. Generally, contractors install cement or steel piers around the perimeter of the house’s slab or near its existing piers if it is a pier and beam foundation. Once in place, hydraulic jacks lift and level the house and transfer its weight to the new supports. There are several different systems and designs out there installed either on the inside of the basement or on the outside of the house.
The cost and system depends on the severity of the problem and the type of foundation involved.