MT Drains & Plumbing logo

6 Things You Need To Know About Basement Crack Repair

horizontal basement wall crack
The walls of your basement hold up not just the basement, but also the weight of the building above it. This means your basement walls are crucial to the structural integrity of your entire home.
Unfortunately, basements are constantly under threat from various factors, particularly cracks. When cracks form, they let in moisture from the soil on the other side of the basement wall.
Ignoring the problem will only make it worse. This can lead to mold growth, cause damage to items in your basement, and generally make the basement unsafe.
Fortunately, a basement crack repair is something you can DIY or hire a professional to fix. But handling a basement foundation crack repair yourself isn’t always the best option, especially if you don’t know the cause of the crack.
To avoid complications from applying the wrong approach to a basement floor crack repair, here are six important things you should know.

1. Cause of the Wall Crack

Most cracks occur over time and can go unnoticed for years until they start to leak moisture into the basement. Depending on the type of crack and where you live, it can expand with each season change.
In most cases, basement wall cracks are due to:
    • Shrinkage: This is due to the concrete foundation of the basement drying too quickly, causing it to shrink and lead to hairline cracks in the wall.
    • Settling: This usually occurs after a building’s construction. Once the house is complete, the soil beneath it gradually compresses under its weight. As the house presses down on the soil, it will settle into the ground. The movement of the building leads to cracks, which can grow larger as the building settles further.
    • Movement: Shifts in the ground due to seismic activity can cause cracks to appear. The more frequent and intensive the seismic activity is, the larger and more plentiful the cracks may be.

2. Floor Cracks vs Wall Cracks

The same causes of a basement wall crack can also cause basement floor cracks. But unlike wall cracks, floor cracks usually don’t leak moisture into the basement unless there’s excess water or moisture in the soil beneath the basement floor.
If the cracks beneath your basement floor are leaking moisture, consider installing a floor drainage system or sump pump to get rid of the moisture.
Also, sealing basement floor cracks is more difficult than basement wall crack repair. That’s because the constant moisture leakage from the floor crack can stop the repair from holding.

3. Choosing the Right Repair Method

The most effective approach to basement foundation crack repair depends on the type of crack and the material used to build the breaking foundation.
For example, a poured concrete foundation with a crack is fixable by filling it with a flexible urethane sealant that expands. You will have to apply the sealant into the crack with an injection because the concrete floor is one solid piece.
On the other hand, using an injection to apply a sealant won’t work if the foundation is made with stones, bricks, or blocks. That’s because the foundation consists of several pieces held together by porous mortar. A sealant won’t be able to hold the whole thing together.
To prevent the moisture caught under the liner from seeping in, consider installing an under-floor drainage system to redirect the moisture elsewhere.

4. Using Epoxy vs Urethane Injection

Epoxy is strong enough to fix cracks in a poured concrete foundation. But that’s only if you live in an area where ground pressure won’t push against the foundation after the repair is complete.
If there is such ground pressure, it will split the epoxy seal, reopening the crack and leading to moisture leakage. In such a situation, a better solution is using urethane injection instead of epoxy. It’s more flexible and longer-lasting, making it more resistant to ground pressure.

5. Repairing Previously Repaired Cracks

Resealing a crack that was once fixed is more difficult. For best results, it’s best to first clean away as much of the old sealant as possible before resealing it. You could also seal the crack from outside with elastomeric membrane or sodium bentonite for a tighter fix.
Why Is There a Crack in the Basement Wall?

6. Fix all Cracks

If you fix a crack because it’s leaking and ignore others that aren’t, the leaking moisture will simply find its way to the next crack and pour from there. That’s because water always heads for the point of least resistance and a crack offers less resistance than a solid wall.
To save money and enjoy greater peace of mind, it’s best to have all your cracks fixed at once, rather than one at a time. That way, you won’t have to keep calling the repairman over to fix the same problem within a short time frame.
These tips should help you with the basics of how to repair crack in basement wall. For more on basement crack repair and for long-lasting results, give us a call to speak with one of our waterproofing experts.

Paul S

Paul has more then 20 years in basement waterproofing and plumbing projects experience. Looking for an advice from an expert plumber? Make sure to read Paul's articles about residential waterproofing and plumbing projects in Toronto.

Related Posts

Need Help? Contact Us


Contact Us

We Offer FREE onsite estimates

Please fill the form below and we contact you as soon as possible to schedule a service call and provide you with an estimate.