Every building will be affected by the environment around it. Bowed walls are one such effect that could happen to your house. The unfortunate reality is that by the time you see walls bowing – leaning inward or appearing to be sideways – the damage has already accumulated to the foundation. The worst case scenario which any homeowner wants to avoid is scariest of all: if not repaired, bowed walls can cause your house to cave in! So what can you do to spot the warning signs and do damage control to ensure the safety of your family and home?
The main warning sign in basements is cracks in poured walls. You’ll also see hairlines starting in block walls going down through the mortar joints. After a wall has been painted a couple times, the hairline cracks should stop spreading. If they don’t, there’s likely a problem with the foundation. You’re less likely to spot warning signs on the exterior of your home, but one thing to look for is sinking concrete along the driveway side if you have a driveway that butts up against the house. If your home’s foundation is weakened, head off more damage with foundation crack repair.
Expansive clays in Michigan soil are the biggest reason for bowed walls. When dry clay comes in contact with water, it can expand – sometimes up to 10 times! When the clay expands, it creates hydrostatic pressure. Now imagine this happening in the soil around your home, and the problem becomes clear. The walls can absorb a certain amount of pressure before they start bowing, but if you’ve done nothing to relieve it, the clays will keep expanding and the pressure will keep building, until you have a house with such an uneven floor that you can roll a ball from one side to the other without even pushing it.
Bowed walls can be straightened and strengthened over time. At DryHouse, we use steel beams with a 4000 psi strength – meaning they can handle up to 4000 pounds of pressure per square inch. These are built directly into the floor joints, provide 100% top-to-bottom support, and slowly straighten walls over time.
Bowed walls on houses with more spacious property can also be straightened using plate anchors. One is attached to the house and another is buried in the soil about 15 feet away from the house; the two are connected by a threaded rod and straighten walls more quickly, sometimes within just a few years. Anchors only grab an area about four feet in diameter, unlike steel beams which support the entire wall. As a result, we try to use steel beams as much as possible.
In homes with crawl spaces, a build-up of hydrostatic pressure can actually cause the interior floor to sink. Older homes in particular are often built with less stable supports that aren’t very deep, resulting in crawl spaces that start to deteriorate only after 10-20 years.
Luckily, we can raise houses from underneath using sturdy, supportive stanchions, along with I-beams to supplement broken beams and floor joints. We also seal crawl spaces off to prevent moisture from getting in, as that is another major culprit of foundation damage.
Due to the lack of depth in the ground, it’s much easier to straighten out bowed walls in crawl spaces. That being said, they are still carrying the same amount of weight, so it’s just as important to be careful and fully repair any foundation damage to your home.