7 Signs Your Foundation Is Moving Under Your House

TL;DR: Foundation movement usually announces itself through cracks wider than 1/4 inch, doors and windows that stick without warning, and floors that slope more than 1 inch over a 20-foot span. Catching these signs early — often years before a sale — can mean a $3,000 crack repair instead of a $15,000-$30,000 pier system, and it changes how you negotiate if you're selling.

_Last reviewed: July 2026 · 7 min read_

You noticed the crack in the drywall six months ago and told yourself it was nothing. Now the back door won't latch, and you're starting to wonder if "nothing" is actually a $20,000 problem waiting to surface at your next home inspection. Here's how to read the signs before a buyer's inspector does it for you.

Okoniq Property Hub helps homeowners log cracks, door alignment issues, and repair estimates over time, so you have a documented history if a buyer or contractor ever asks "how long has this been happening?"

What do foundation cracks actually mean?

Not every crack means trouble, but the shape and width tell you a lot. Hairline cracks under 1/16 inch that run straight up and down are usually just concrete curing or minor settling — normal in homes of any age. Cracks wider than 1/4 inch, especially ones that run diagonally or in a stair-step pattern across brick or block, point to actual foundation movement.

Horizontal cracks are the ones to worry about most. They often mean soil pressure is pushing against a basement or crawlspace wall from the outside, which can eventually cause the wall to bow. If you see a horizontal crack longer than a few inches, or one where the wall has bulged inward more than 1 inch, get a structural engineer out before doing anything cosmetic. Painting over it doesn't stop the pressure, and it will show up again during a home inspection contingency if you sell within the next few years.

Why do doors and windows suddenly stick?

Doors and windows stick when the frame around them shifts out of square, which happens when the foundation beneath that section of the house rises or drops unevenly. A door that swings open on its own or won't latch without extra force is one of the earliest signs of foundation movement, often showing up before any visible cracking.

Test it simply: close the door and look at the gap around the edges. An even 1/8-inch gap all the way around is normal. A gap that's wide at the top and tight at the bottom (or the reverse) means the frame has racked out of square. If this is happening on multiple doors in the same part of the house, especially near an exterior wall, that's a pattern worth having checked rather than one-off cosmetic wear.

How uneven should floors be before it's a problem?

A floor slope of more than 1 inch over 20 feet is generally considered significant and worth investigating. You can test this yourself with a 6-foot level or by rolling a marble across the floor in a few rooms — if it consistently rolls toward one wall, that's a sign of differential settlement, meaning one part of the foundation is sinking faster than the rest.

Older homes built before the 1970s often have some natural settling and a little slope is common and not alarming. The concern is new or worsening slope, especially paired with cracks or sticking doors in the same area. If you're weighing whether to fix this before listing, it connects directly to repair vs price reduction decisions — some buyers will walk from a house with a documented slope issue, while others will negotiate price instead of asking for the repair.

| Sign | Normal / Minor | Worth a Professional Look | |---|---|---| | Crack width | Under 1/16 inch, vertical | Over 1/4 inch, diagonal or stair-step | | Floor slope | Under 1 inch per 20 feet | Over 1 inch per 20 feet | | Door gaps | Even 1/8 inch all around | Uneven, sticking, self-opening | | Wall movement | None visible | Bowing over 1 inch, horizontal cracks |

What about the outside of the house?

Exterior clues often show up before interior ones. Gaps between the foundation and the soil around it, chimneys that lean away from the house, or brick veneer separating from the frame at the corners are all signs the foundation has shifted. Check your gutters and downspouts too — if they're dumping water within 2 feet of the foundation, that's a common cause of the soil movement that leads to cracking in the first place.

Grading matters more than most homeowners realize. Soil should slope away from the foundation at roughly 6 inches over the first 10 feet. If water is pooling near the house after rain, that expanding and contracting soil is likely contributing to whatever cracking you're seeing inside.

Does this affect what my house is worth if I sell?

Yes, and it's worth handling before you're mid-contract. A documented, professionally repaired foundation issue is far easier to sell around than an undisclosed one a buyer's inspector finds cold. Sellers who get an engineer's report and either fix the issue or price the home accordingly tend to close faster than those who hope nobody notices. This ties directly into pricing your home right — a house with known foundation work needs to be priced with that history in mind, not against comparable homes with clean reports.

Some sellers offer a home warranty or a structural repair credit at closing instead of doing the work themselves, which can keep the sale moving without draining cash before you move. Whatever you choose, disclose it. Most states require disclosure of known structural defects, and skipping that step creates legal exposure that costs far more than the repair would have.

FAQ

How much does foundation repair typically cost?

Minor crack injection repairs run $300 to $1,000 per crack, while pier and beam systems for significant settlement typically cost $10,000 to $30,000 depending on the size of the home and number of piers needed.

Can I sell a house with foundation problems?

Yes, but you must disclose known issues in most states, and buyers will often request a price reduction or repair credit rather than walk away, especially if you provide an engineer's report showing the movement is stabilized.

How do I know if a crack is getting worse?

Place a piece of tape across the crack and mark the date, or use an epoxy crack monitor gauge from a hardware store; if the crack extends past the tape or the gauge shows movement over a few months, it's active and worth a professional evaluation.

Is foundation settling covered by homeowners insurance?

Standard homeowners insurance typically excludes gradual settling and earth movement, though it may cover foundation damage caused by a covered peril like a burst pipe or storm; check your policy's exclusions section directly.

When should I call a structural engineer instead of a foundation repair company?

Call an engineer first when you see horizontal cracks, bowing walls, or slope over 1 inch per 20 feet, since engineers give an unbiased diagnosis while repair companies may recommend the fix they sell.

This is educational information, not structural engineering or legal advice. Call a licensed structural engineer for any crack wider than 1/4 inch or floor slope over 1 inch per 20 feet, and consult a real estate attorney about disclosure requirements in your state before selling.