To most people, their home’s foundation seems like a pretty big deal, a massive slab of poured concrete or structure of concrete block. It was built by a bunch of burly guys with big trucks, so it seems like something that’s here to stay, almost impregnable.
Water, on the other hand, seems like a little thing. It comes down as rain, makes little puddles, runs out of the kitchen tap. We wash in it, drink it, even play in it. What harm can it do?
Ever seen the Grand Canyon?
Seriously, water, while a benevolent thing for human society, is also one of the most destructive forces known to man. In motion, it can erode even the densest of stone. Just sitting in place, it can dissolve both natural and man-made elements and, in the ground, it can create pressure that can move the heaviest and most firmly anchored objects – like a foundation.
How Water Can Damage a Foundation
There is water in the ground almost everywhere on earth. In some places it is buried so deep that the area seems dry and arid but it’s still there. In other places, it’s so close to the surface that it pops up in springs and can be accessed by shallow wells.
Of course, when water hits the ground surface in the form of rain or snow, it soaks into the earth. In soils that drain well, like loam or sand, most of this water passes through to an underground aquifer. In expansive soils, like the clay that is common in the Chicago area, the soil doesn’t drain well and absorbs and holds the water.
Of course, just like a common household sponge that also absorbs and holds water, the saturated soil expands significantly from the absorption. When this soil surrounds the foundation of a home, its expansion is stopped by the foundation walls but the force behind the expansion continues, creating pressure against the wall.
If this pressure continues to increase, something has to give and most often it’s the foundation wall. Cracks begin to form in poured concrete walls and in the mortar joints of masonry walls. If the damage stops there, the cracks will seep water into the basement. If it continues, the cracks in poured concrete will multiply and worsen and, eventually, the wall will begin to move, usually tipping or rotating inward from the top. The blocks or stones of a masonry wall will begin to bulge inward in the center and ultimately shift out of line.
In either case, the entire foundation has been destabilized and the structure of the home is in jeopardy.
Of course, there’s also the water deep underground and it creates pressure against the foundation as well. Known as “hydrostatic pressure,” it pushes upward against the foundation and can cause cracks in basement floors. While usually insufficient to create foundation movement, it can force water into the basement through those floor cracks and the cove joint.
However, in times of drought when even the water this deep underground can be siphoned away by trees and large plants, its absence can cause significant foundation damage, too. When this process occurs, known as “desiccation,” the previously saturated and expanded soil under the foundation will shrink and become compacted leaving a void in the soil that supports it. When the void is large enough, the foundation can drop or sink, which causes damage not only to the foundation itself but to the aboveground structure it supports.
In either case, significant repair is required and, like many types of damage, is less costly and disruptive to fix the sooner it is caught.
A homeowner who is facing damage to his or her foundation caused in one way or another by water will need the services of a foundation repair contractor that understands the power of water. At U.S. Waterproofing, our foundation experts not only understand the engineering behind foundation construction and repair, they draw on our 56 years experience in basement waterproofing to manage water outside the home to prevent the damage it can cause. Why not ask for a free consultation on your foundation?