Cracks in your foundation can spell big trouble for your whole house, but not every crack can simply be patched and forgotten. Understanding the underlying causes, and preventing the same problem from recurring in the future will ensure that you're not constantly throwing money at it with limited results. More importantly, having this understanding will help you decide whether or not a contractor's foundation crack repairs will appropriately address the problem in the long term.
One of the best methods for judging the seriousness of a crack is the presence of moisture, especially in slab foundations or basement floors. A dry crack in a floor or slab usually results from the natural contraction of concrete as it dries and sets. Alternately, the presence of moisture in a crack on any surface usually suggests hydraulic action caused by improper drainage around your foundation.
As water in the surrounding soil freezes it expands, exerting incredible force against anything in its path. Over time, this force can cause basement walls to bow, or slab foundations to shift, and the resulting cracks will allow water inside, where it can exert those same forces in a more dramatic fashion. While filling the crack is critical, it's even more important to address the drainage issue that caused it in the first place by installing a proper weeping system and directing the flow of ground water away from the house.
Step Cracking in Masonry Foundations
Unlike poured concrete, masonry foundations are more porous and flexible under pressure. Be vigilant though, and keep an eye on your brick or cinder block foundation walls. Dry step cracking alone isn't necessarily cause for concern, but when paired with dampness, bowing walls or bricks that have been split, you should start to worry.
Bowing of masonry walls are usually the result of improper structural support for the building itself, causing the wall to begin bending inward. The only real solution in these cases is to restructure the wall, building a new wall on the interior of your basement. As with any foundation cracks, the presence of moisture indicates a drainage issue, and masonry isn't immune to the forces that freezing water can exert. Make sure your foundation contractor has confirmed your drainage is adequate before you agree on a course of action.
The foundation of your home is one of its most critical parts, but it's also a component most homeowners rarely look at. If you notice a slope in your floors, a shift in your walls, or any other signs that something isn't level, contact a foundation contractor for an evaluation.