Signs You Have a Foundation Problem — A Plain Guide From a 40-Year Ottawa Foundation Specialist.
The 10 symptoms worth taking seriously, and which ones can wait.
Owner on every job
Ottawa local for 40+ years
No subcontractors
Why most foundation symptom articles are written to scare you.
If you Google "signs of foundation problems," most of what you find is contractor blogs designed to get you to call. Every symptom is presented as urgent. Every example points to a $20,000 quote.
The truth is more boring and more useful: some foundation symptoms need attention this week, some can wait years, and some are nothing at all. This guide is written to help you figure out which one yours is — and what to actually do next.
If after reading this you're still not sure, send us a photo or book a free inspection. We'll tell you the truth.
[Photo: 1. Cracks in your foundation wall]
1. Cracks in your foundation wall
- What it looks like
- Cracks wider than a credit card, any crack that's actively growing, horizontal cracks at any width.
- What causes it
- Depends on the crack type. Vertical and hairline cracks are usually fine. Horizontal cracks usually mean lateral pressure on the wall and need attention soon.
- Severity
- ★★★☆☆Varies
- What to do
- See our full guide to crack types
[Photo: 2. Doors and windows that suddenly stick]
2. Doors and windows that suddenly stick
- What it looks like
- A door or window in your house that worked fine for years and now sticks, drags, or won't latch properly.
- What causes it
- The house frame has shifted, usually because the foundation moved. Sudden onset is the key word — long-standing sticky doors are usually just settling that finished decades ago.
- Severity
- ★★★☆☆Act this month
- What to do
- Get an inspection.
[Photo: 3. Sloping or uneven floors]
3. Sloping or uneven floors
- What it looks like
- A marble that rolls across the floor on its own. A noticeable tilt when you walk.
- What causes it
- The floor structure is no longer level, usually because the foundation has settled differentially (one part dropped more than another).
- Severity
- ★★★☆☆Depends
- What to do
- Inspection needed to determine severity.
[Photo: 4. Water in the basement]
4. Water in the basement
- What it looks like
- Standing water after rain or snowmelt; persistent dampness; water stains on walls; a basement that smells different than it used to.
- What causes it
- Water is finding its way in. Could be exterior membrane failure, weeping tile failure, drainage problems above ground, or sometimes plumbing.
- Severity
- ★★★★☆Act soon
- What to do
- Mold and structural damage compound the longer water sits.
[Photo: 5. Stair-step cracks in brick]
5. Stair-step cracks in brick
- What it looks like
- Cracks above doors or windows in your exterior brick that follow the mortar lines in a stair-step pattern.
- What causes it
- Differential movement in the underlying foundation. The brick is showing you what the foundation is doing.
- Severity
- ★★★☆☆Act this month
- What to do
- Inspection needed to determine what's moving.
[Photo: 6. Gaps around windows and doors]
6. Gaps around windows and doors
- What it looks like
- New gaps you can see daylight through; visible separation of trim from the wall; weatherstripping that no longer makes contact.
- What causes it
- The wall containing the window or door has shifted relative to the frame. Often paired with sticky doors.
- Severity
- ★★★☆☆Act this month
- What to do
- Same priority as sticky doors — get an inspection.
[Photo: 7. Bowing or buckling foundation walls]
7. Bowing or buckling foundation walls
- What it looks like
- A basement wall that's curving inward, especially in the middle. Use a long straight-edge against the wall to measure deflection.
- What causes it
- Lateral pressure (soil, water, frost) is pushing the wall inward. Once it starts, it accelerates.
- Severity
- ★★★★★Act this week
- What to do
- This is one of the more serious signs. Call for urgent inspection.
[Photo: 8. Crumbling parging or surface deterioration]
8. Crumbling parging or surface deterioration
- What it looks like
- Parging on the visible portion of the foundation that's blistering, peeling, or crumbling away.
- What causes it
- Usually just bad parging that needs to be redone — but sometimes it's hiding a real foundation crack underneath.
- Severity
- ★★☆☆☆Usually cosmetic
- What to do
- Occasionally hides something more. Get a look.
[Photo: 9. Smells in the basement]
9. Smells in the basement
- What it looks like
- Musty, earthy, or mildew smells that weren't there before; sometimes a sewer-like smell.
- What causes it
- Usually moisture without visible water — humidity high enough to grow mold or mildew somewhere out of sight. Sewer smells can mean a sump pit issue or trap dryout.
- Severity
- ★★★★☆Act soon
- What to do
- Mold gets worse fast.
[Photo: 10. Visible settling or one corner of the house dropping]
10. Visible settling or one corner of the house dropping
- What it looks like
- Visible drop at one corner of the house when sighting along the eaves or foundation line; cracks in interior walls that follow a corner-down pattern.
- What causes it
- Differential settlement of the foundation, often soil-related.
- Severity
- ★★★☆☆Act this month
- What to do
- Get an inspection.
Severity guide — what to act on when.
This week:
- Bowing or actively moving wall
- Active basement flooding
- Sump pump that just failed
This month:
- New sticky doors or window gaps
- Stair-step cracks in brick
- Visible settling
- Mold smells
Eventually (this year):
- Cracks that aren't growing
- Failed parging that's cosmetic only
- Minor floor unevenness that's been there since you bought the house
Probably never:
- Hairline shrinkage cracks
- Settling that finished 30 years ago
- One corner that's been "low" since you moved in
Get a free assessment.
If you've checked through this list and you're still not sure where you stand — that's exactly what the free inspection is for. We come look in person, tell you what we see, and tell you whether you need to do anything about it.