The foundation acts like the roots of your home: it ensures its stability and durability. It is, however, often out of sight, out of mind… until the day a crack appears or water leaks in and you finally start paying attention!
As a homeowner, you have the ability to prevent problems and, at the same time, preserve your property’s value.
Not All Cracks Are a Cause for Concern
When a foundation is damaged, one or more cracks will appear. The first thing to understand is that this isn’t necessarily a catastrophe. There are two possible scenarios:
- The cracks are simply due to the concrete shrinking over time and in no way compromises the structure’s integrity.
- Cracks may indicate that the soil has moved or that water has gotten in.
Identifying When a Crack Must Be Addressed
If the crack is long, horizontal, or widens over the course of the year, you should worry. Calling in an expert is recommended. Not only will professional repairs protect your home, but they will equally reassure future buyers if you eventually decide to sell.
Fine, vertical, superficial cracks (less than 3 mm), for their part, are generally safe. Of course, you should still keep an eye on them, but applying a little sealing product is often enough to stop water from seeping in.
5 Ways to Prevent Cracks in the Foundation
1. Make Sure Runoff Is Directed Away from the House
Water is a foundation’s number one enemy. Inadequate outdoor water runoff management can not only cause cracking, but it can also lead to soil collapse.
Warning Signs
- Stagnate pools around the house
- A very damp basement
Solutions
- Add a downspout extension. This may seem trivial, but it can make a huge difference by keeping water away from the base of the foundation.
- Clean the gutters in spring and fall to avoid overflow.
- Check the land gradient. The ground should slope away from the foundation walls over at least 2 metres to stop water from accumulating next to them.
- Install a French drain. This is an underground system which collects water around the foundation and drains it away. If your home already has one, have it inspected since it can become clogged over time.
2. Watch Out for Snow and Cold
In Québec, temperature variations cause the soil to expand and contract, exerting pressure on the foundation.
Solutions
- Stop the soil from freezing in direct contact with the foundation by installing strip insulation or rigid polystyrene boards around the foundation’s outer perimeter.
- Don’t completely clear the foundation of snow in winter; a thin layer acts as a natural insulator.
- Prevent spring snowmelt runoff from saturating the soil by digging small drainage ditches.
3. Beware of Tree Roots
Certain tree species (silver maple, poplar, willow, etc.) have very vigorous roots. They don’t pierce concrete foundations, but they do shift the nearby soil and can dry it out on one side (by absorbing water), destabilizing the walls.
Solutions
- Plant at a safe distance: 7 to 10 metres for big trees and 3 to 4 metres for smaller ones.
- Install a root barrier: a membrane buried vertically to redirect tree roots.
- Prune roots and trim trees as needed.
- Water evenly to avoid creating pockets of damp and dry soil around the house.
- Always prepare the site before you fell a tree to prevent soil compaction. In any case, tree removal usually requires a municipal permit.
4. Limit Your Use of Chemicals and Salt
Your property’s concrete foundation is chemically vulnerable to de-icing salt (which seeps into the concrete’s pores and corrodes its rebar framework); to certain mineral salts naturally present in the soil; or even to chemical products used in snow removal, cleaning, or decontamination.
Solutions
- Use as little salt as possible around the foundation. Opt instead for sand or less corrosive de-icing products.
- Rinse the foundation in spring to remove salt build-up.
- Protect the concrete by applying the appropriate sealant or water repellent.
5. Consider Weight and Structural Loads When Renovating
The foundation must support the house’s weight. If renovations increase this weight (by adding a storey, a hot tub, an imbalanced load-bearing wall, for example), or if the soil beneath the footings doesn’t provide a uniform bearing capacity, the foundation can sink in certain areas, leading to cracks and an unlevel floor.
Solutions
- Assess the ground’s load-bearing capacity before adding storeys or heavy components (a hot tub, a load-bearing wall).
- Evenly distribute the load during renovations.
- Consult an engineer if the new load exceeds the home’s initial structural capacity.
Although not its most glamorous aspect, the foundation is the structural heart of the home. By paying a little closer attention to it, you’re not only protecting your property’s structure; you’re safeguarding your real estate investment.