Finding a foundation crack doesn’t necessarily mean it’s going to become a major problem.
But foundation cracks shouldn’t simply be ignored without understanding what you’re looking at.
Some cracks remain relatively unchanged for years. Others can leak, widen or develop alongside foundation movement.
The important thing is knowing which changes to watch for.
Why Do Foundation Cracks Develop?
Concrete is strong, but it isn’t completely immune to cracking.
Foundation cracks can develop for several reasons, including:
- Concrete shrinkage
- Settlement
- Soil pressure
- Temperature changes
- Construction joints
- Foundation movement
The cause matters because a straightforward shrinkage crack is very different from cracking associated with wall movement.
Can a Small Foundation Crack Become Larger?
It can.
That doesn’t mean every hairline crack will continue growing.
If you’re monitoring a crack, look for changes in width, length or displacement.
Taking a clear photo with a date can help you compare the crack over time.
If the crack changes noticeably, it may be worth having it assessed.
Can a Foundation Crack Start Leaking Years Later?
Yes.
A foundation crack that has remained dry doesn’t necessarily mean water can never pass through it.
Changes in exterior drainage, unusually heavy rainfall or saturated soil conditions can expose a water pathway that wasn’t previously noticeable.
Homeowners sometimes discover a leaking foundation crack after years without obvious basement water.
Why Does a Crack Leak Only During Heavy Rain?
The amount of water surrounding a foundation changes with weather conditions.
During a short light rainfall, there may not be enough water around the foundation to produce an obvious leak.
After prolonged or heavy rain, saturated soil can make existing weaknesses more apparent.
This is why some homeowners experience basement leaks only during major storms.
If that’s happening in your basement, our guide to wet basements after heavy rain explains several possible causes.
What Changes Should You Watch For?
Pay attention if:
- The crack becomes wider.
- The crack becomes longer.
- Water begins entering.
- One side appears displaced from the other.
- A horizontal crack develops.
- The wall begins bowing.
- New cracks develop nearby.
- A previous repair begins leaking again.
These signs don’t all mean the same thing, but they provide useful information about whether the condition is changing.
What About Horizontal Cracks?
Horizontal cracks deserve particular attention because they can sometimes be associated with lateral pressure and wall movement.
If the wall is visibly bowing inward, the problem shouldn’t be treated as though it’s simply a leaking crack.
Certain foundation-wall conditions may be suitable for carbon fibre wall reinforcement.
The severity of movement and condition of the wall should determine the repair.
Should You Repair a Dry Foundation Crack?
This depends on the crack and what it’s doing.
A stable, non-leaking crack isn’t the same situation as a crack allowing water into a finished basement.
However, if you’re planning to finish the basement, it’s a good time to inspect visible foundation cracks before covering the walls.
Once drywall, insulation and framing are installed, accessing the foundation becomes more difficult.
If there is evidence that the crack has leaked previously, foundation crack repair may be worth considering before finishing the space.
Can Foundation Cracks Be Repaired From Inside?
Many suitable cracks in poured-concrete foundation walls can be repaired from the interior.
Polyurethane injection is commonly used for leaking foundation cracks because the material can enter and seal the crack.
Interior access can eliminate the need for excavation in many situations.
Our guide to interior vs exterior foundation crack repair explains when each approach may make sense.
What If the Foundation Crack Was Repaired Before?
A previous repair doesn’t necessarily tell you why water has returned.
Sometimes only the visible surface was patched.
In other cases, an older injection may have failed or the new water entry may be adjacent to the original repair.
Clear photographs showing the previous repair, surrounding wall and active water are helpful when determining what may be happening.
Foundation Crack Repair in Durham Region
Aquaphobia Foundation Repair provides foundation crack repair throughout Durham Region, including Ajax, Pickering, Whitby, Oshawa, Courtice, Bowmanville and Newcastle.
If you’re concerned about a crack, send us photos showing the entire wall and close-ups of the affected area.
If the crack leaks, try to take pictures while the water is visible.
Frequently Asked Questions
Does every foundation crack get worse?
No. Some cracks remain stable. The crack’s pattern, movement and whether it leaks are more useful than simply knowing a crack exists.
Should I monitor a foundation crack?
Monitoring a crack can help you identify changes. Dated photos are an easy way to compare its appearance over time.
Why did my foundation crack suddenly start leaking?
Heavy rain, saturated soil or changing drainage conditions can expose a water pathway through an existing crack.
Can you inject an old foundation crack?
Many existing poured-concrete cracks can be candidates for injection, but previous repairs and the condition of the crack need to be considered.
Is a horizontal crack worse than a vertical crack?
Horizontal cracks can sometimes be associated with wall pressure or movement and deserve closer evaluation, particularly if the wall is bowing.