Foundation cracks are no laughing matter. Although some are more serious than others, foundation cracks are often a clear indication that the system has weakened. With winter just around the corner, you should consider a quick inspection of these walls before they’re covered in snow; melting snow (water) will enter your home whenever possible.
Not all cracks are serious, when concrete cures or dries it sometimes cracks. It's not uncommon for new homes to have some cracks along the foundation or in the basement floor slab. For this reason, we recommend allowing a few freeze-thaw cycles (winter and spring), before finishing the basement. If any cracks do show up or get worse, they can be fixed first.
So how do you know if it's serious? There are different types of cracks – step, vertical, horizontal, along walls and in basement floors. If a crack can fit a dime, get it checked.
You don't want to see step cracks in cinder block and brick foundations. These types of cracks generally allow water to get into the basement. Cracks in the cinder blocks themselves are also serious; it’s a clear indication that uneven settlement/movement of the home is occurring. If you see them, call a foundation specialist as soon as possible.
Vertical cracks on two adjacent walls could mean the foundation's footing is broken. If that's the case, the footing needs to be repaired, which means excavating all the way down to the footing. This is sort of a big job. But there should be at least two cracks. If there's only one vertical crack, then it could be the result of concrete shrinkage as the wall cured.
Horizontal cracks along the foundation wall can also be serious. They can indicate that the structural integrity of the wall has been compromised either due to freeze-thaw cycles or hydrostatic pressure. Hydrostatic pressures occur when groundwater or extra water from rain/melted snow, presses against the foundation wall from the outside. This pressure is very strong and can cause walls to buckle inwards and water to seep in. A horizontal crack about three or freezing and thawing typically cause four feet below grade. That's where the frost line is usually located.
Other cracks which get longer and wider, are also no good. These might even cause parts of the concrete slab to heave upwards, or to settle downwards. Foundation specialist might recommend mud-jacking, which involves drilling holes into the part of the slab that's lower and using pressure to pump concrete in and raise the slab up so it's even.
So what to do before the snow hits? The best foundation repairs happen from the outside.
In serious cases, the wall should be excavated to expose the crack on the outside. The crack is then filled with hydraulic cement that expands as it dries, creating a seal. A waterproof coating is sprayed on and it cures to a rubbery membrane that is 100-per-cent waterproof. A dimpled membrane is fastened over top. This process is not cheap but it's effective.
If you don’t want to undertake these repairs right now, you should at least monitor them to see if the damages are worsening. If you find any cracks in your foundation, either inside your basement or on your home's exterior, mark them with tape and check them again after a few months. If they haven't changed in any way, they can usually be filled in with an epoxy injection or expandable foam. But if they get worse bring in a pro, such as a structural engineer or foundation specialist, to assess the situation and recommend the proper solution.
We hope you enjoyed this article on foundation cracks and repairs! If you have any other questions, please don’t hesitate to contact us!