Just about every homeowner understands that a period of heavy rain will often result in a wet basement. It’s not that the rain water is running directly into the basement, however; it is quickly saturating the soil around the foundation and the increased ground water is making its way in through any opening it can find.
Of course, heavy rains can also overwhelm municipal storm or sanitary sewer systems (one and the same in Chicago) and cause back-ups, but that’s another story.
What the average homeowner may not realize, though, is that an extended period of rain may be doing other damage that is less easily detected. This type of damage may take longer to occur but can be more devastating and more costly to repair than the wettest of wet basements.
Heavy Rains Cause Chicago Structural Foundation Damage
Foundation damage is very common in the Chicago area but not all of it is structurally significant. Minor cracks (less than 1/8” wide) often occur in poured concrete foundation walls; mortar joints in masonry walls can also crack and deteriorate. This non-structural foundation damage is the kind that leads to basement seepage and usually can be quickly and permanently repaired.
The more serious kind of foundation damage, the kind that jeopardizes the stability of the foundation and the home above, is usually the result of one of two things happening to the surrounding soil, both of which have water as their root cause.
One way in which a foundation can suffer structural damage is by extreme settling, dropping or sinking. This occurs when the soil underneath the foundation shrinks and becomes compacted, often caused by a wet/dry weather cycle where large amounts of rain cause the soil to become saturated and swell, followed by periods of drought that cause the water to be extracted and the soil to shrink. This occurred frequently in the Chicago area during the summer of 2012.
The other way water causes structural foundation damage is far more common. This occurs when heavy rains over-saturate the soil surrounding the foundation’s walls, causing the soil to swell. When the soil increases its volume, it exerts lateral pressure on foundation walls, causing them to crack and, in the worst cases, actually move. Those minor cracks that cause seepage are one result of this pressure but when the pressure grows it can cause severe cracking, bowing or bulging of masonry walls and tipping or rotating inward of poured concrete walls.
Of course, soils of different composition absorb water and swell at different rates. Sandy soil, for example, drains very well and absorbs very little water so foundation damage from lateral pressure is infrequent. Clay soil, on the other hand, is extremely absorptive and elastic, so it swells at a considerable rate and is most likely to cause foundation damage. Unfortunately, clay soil is by far the most common type in the Chicago area.
When this type of wall cracking and/or movement occurs, the wall must be stabilized to prevent further damage to the home. Depending on the severity of the problem, the wall can be permanently stabilized with either carbon fiber strips or steel wall bracing; if the problem is neglected and major wall movement occurs, the wall may have to be replaced.
Regardless of the remedy, the one thing any Chicago homeowner needs when facing structural foundation damage is the advice of a foundation repair contractor that knows how to diagnose, repair and prevent the recurrence of even the worst problem. The foundation repair experts at U.S. Waterproofing make use of thorough inspections and engineering data to permanently and cost-effectively repair structural foundation damage. Why not ask us for a free consultation?