What are the common warning signs that indicate a foundation problem?

The common warning signs of a foundation problem are cracks in the walls or floor, doors and windows that stick or won’t latch, floors that slope or feel bouncy, gaps where the wall meets the ceiling or trim, and a basement wall that bows or leans inward. One sign alone might be nothing. Several together usually mean the foundation is moving, and that is worth a look.

Here is what we see in New Hampshire basements, in plain order.

Cracks come first. Not every crack is trouble. A thin hairline crack in poured concrete is often just the concrete curing, and it can sit there for years doing nothing. What we worry about is a crack that is wider at the top than the bottom, a crack that runs at a stair-step angle through block, a crack that keeps growing, or a crack that leaks. Those tell us the wall is taking pressure it was not built to take. Around here that pressure usually comes from the soil. The dirt packed back against your foundation when the house was built is disturbed backfill. It is looser than the ground around it, so it drains slow and holds water, and water-heavy soil pushes hard on a wall. Add NH frost. When that wet soil freezes it swells and shoves the wall inward. That is frost heave, and it is the reason we see so many bowing walls up here.

Doors and windows are the next tell. A door that suddenly sticks, a window that won’t slide, a latch that no longer lines up. When a foundation settles unevenly the whole frame of the house racks a little, and the openings go out of square first. One sticky door in humid July is normal wood swell. Three doors going crooked in one season is the house moving.

Floors talk too. A floor that slopes, a spot that dips, a bouncy or spongy section. In an older home that often points down at the basement, where a support post has settled or a wooden beam or sill has rotted and lost its strength. Walk your basement and look up. A beam sagging in the middle, a post sitting in a puddle, the rim of wood along the top of the foundation gone dark and soft. Those are real.

Then the gaps. Trim pulling away from the wall. A line opening up where the wall meets the ceiling. A staircase separating from the wall it’s attached to. Brick or a chimney cracking on the outside. None of these are the foundation itself, but they are the house telling you the foundation underneath has shifted.

And water. Where water gets in, the soil outside is staying wet, and wet soil is what pushes on walls and rots wood. A damp basement, a puddle at the floor wall joint where the slab meets the wall, white chalky residue on the block. Those go hand in hand with the cracking and the movement. (For the building-science side of how foundation soil and water behave, the U.S. Department of Energy’s Building America program is a solid neutral read. Source: DOE Building America.)

A lot of what scares homeowners turns out to be cosmetic. A hairline crack that doesn’t leak, a single seasonal sticky door, a little settling in a house built decades ago that stopped moving long ago. You don’t need a structural job for those. The way to know is to watch and measure. Mark the end of a crack with a pencil and a date. If it grows over a few months, call someone. If it sits still, it’s likely been still for years.

What turns a wall crack or a leaning wall into a fix depends on what we find. Foundation crack repair by epoxy or polyurethane injection starts at $1,000 to $3,000. A wall that is cracking but still mostly straight can be held with carbon-fiber straps at $1,000 to $3,000 for the crack plus $850 each for the straps. A wall taking real pressure may need a power brace at $1,300 per brace. When the footing itself has settled and the house is sinking, that is helical or push piers at $2,700 per pier for the first three, then $2,200 per pier after that to carry the load back down to stable ground. A sagging floor over a tired post is a lally column or floor support at $1,300 to $2,500. A rotted sill or beam is sill and beam replacement at $7,000 to $40,000. A full foundation-wall rebuild is a bigger job, and we price that after we see it, because no two are the same. We self-perform the structural lifting and the helical installs in-house, so you’re not handed off to a sub.

For the full picture, see our structural and foundation repair hub, our foundation repair page, and helical piers. The Forever Dry System is for keeping a basement dry, not for structural work, so don’t let anyone cross those wires. And everything we do is backed by the 603 guarantee.

Ready to look at it?

If you’re seeing one of these signs and you’re not sure how worried to be, let us come look. We’ll tell you plainly if it’s cosmetic or if it’s moving, and what it would take to fix. The inspection and the written estimate are free, and you get a written quote within 24 hours.

Call us at 603-610-1770, or book your free inspection. We’re in East Kingston, and we work New Hampshire, Maine, and Massachusetts.

Related questions

Is every crack in my foundation a serious problem?

No. A thin hairline crack in poured concrete is often just curing and may never do a thing. The ones to watch are cracks that leak, cracks wider at one end, stair-step cracks in block, or any crack that keeps growing. Mark the end with a pencil and a date. If it grows over a few months, call us. If it stays put, it’s probably been still for years. Crack injection, when you do need it, starts at $1,000 to $3,000.

Why do basement walls bow or lean inward in New Hampshire?

Pressure from the soil outside. The backfill against your foundation is looser fill that holds water, and wet soil pushes hard on a wall. Then NH frost freezes that wet soil, it swells, and it shoves the wall inward. That’s frost heave. A wall that’s still mostly straight can be held with carbon-fiber straps at $850 each. A wall under heavier pressure may need a power brace at $1,300 per brace.

My floors slope and a door sticks. Is that the foundation?

It can be, especially if you’re seeing several signs at once. Uneven settling racks the house, and doors and floors go out of square first. Walk your basement and look for a settled support post or a rotted beam. A floor support post is a lally column at $1,300 to $2,500. A rotted beam or sill is sill and beam replacement at $7,000 to $40,000. One sticky door in humid weather, though, is usually just wood swell.

How fast should I act on foundation warning signs?

It depends on whether they’re moving. A crack that’s still and dry can wait while you watch it. A wall that’s actively bowing, a floor that keeps dropping, or a crack that keeps widening should be looked at soon, because those get more expensive the longer they move. The fastest way to know is a free inspection. We’ll come out, tell you straight, and get you a written quote within 24 hours.