Homeowner's Guide · North Vancouver
Is Your Foundation Crack Serious? How to Tell
You spotted a crack in the concrete and your stomach dropped. Take a breath — not every crack is trouble. Here's how to read what you're looking at, so you know whether it's cosmetic or worth a call.
Almost every home develops foundation cracks over time, and most are harmless. But a few types genuinely signal movement you shouldn't ignore. The difference is in the shape, width, and direction of the crack — and whether anything else in the house is changing with it. Here's how to tell them apart.
Usually minor: thin vertical cracks
Narrow, roughly vertical cracks in poured concrete are the most common kind, and usually the least worrying. They typically come from normal concrete shrinkage as the foundation cured in its first few years. If it's hairline-thin, isn't growing, and nothing else in the house has changed, it's most likely cosmetic. Worth monitoring — not worth panicking over.
Take seriously: horizontal cracks
A crack running horizontally along a foundation wall is the one to respect. It often means the wall is under sideways pressure from soil or water pushing against it — exactly the load these walls aren't meant to take. On the North Shore, saturated, sloping ground makes this a real and recurring cause. Horizontal cracking warrants a professional look.
Take seriously: stair-step cracks in block or brick
In a block or brick foundation, cracks that climb in a stair-step pattern along the mortar joints usually point to differential settlement — one part of the foundation sinking more than another. The wider the step and the more it's opening, the more it matters.
The width test
A simple rule of thumb: if you can slip the edge of a coin into the crack (roughly 3mm or more), or if it's visibly wider at one end than the other, treat it as more than cosmetic. Hairline is usually fine; a gap you can feel is worth investigating.
The real tell: is anything else changing?
A crack on its own is one data point. A crack plus other symptoms is a pattern. If you also notice any of these, it moves from "monitor" to "get it assessed":
- Floors that have started to slope, sag, or feel bouncy
- Doors or windows that suddenly stick or won't latch
- The crack is actively growing, or keeps returning after being patched
- Gaps opening where walls meet floors or ceilings
- A basement or foundation wall that looks like it's bowing inward
For the full picture, see our guide to the 7 signs your home has a structural problem.
Why North Shore foundations crack in the first place
North and West Vancouver are full of older homes on steep, sloped lots with original foundations — and our wet winters, moving soils, and seismic reality put loads on those walls that flat-lot, newer builds never feel. That's why a returning or horizontal crack here deserves attention: the ground itself is often the culprit, and it won't stop on its own.
If a crack keeps coming back, the cause wasn't fixed
The most common mistake is sealing a crack without addressing why it formed. Patch a crack caused by soil pressure or drainage and it will simply return — often wider. A lasting repair starts with diagnosing the cause. Depending on what's found, the fix might be underpinning, improved drainage and waterproofing, or structural reinforcement — and the right method depends entirely on the diagnosis. For what those repairs involve and cost, see what foundation & structural repair costs.
Not sure what you're looking at? Book a Structural Assessment
Send us a photo or book an on-site look. We'll tell you honestly whether it's cosmetic or structural — no scare tactics — and if it needs work, you'll get a clear plan and a fixed quote.