What can be done to fix a house’s foundation after it is built?

Plenty can be done, and you almost never have to rebuild. Most settled or cracked foundations get fixed from the inside with targeted repairs: crack injection for leaks, carbon-fiber straps or a power brace for bowing walls, and helical or push piers when the footing is sinking. Costs run from $1,000 to $3,000 for a single crack to $2,700 per pier for the first three, then $2,200 per pier after that for piers, and we give you a free inspection with a fixed quote within 24 hours.

A house can move long after it’s built. The dirt around your foundation is disturbed backfill, the loose soil that got pushed back in when the house went up. It drains slowly and holds water. Add a New Hampshire winter and frost heave pushes on the walls. Over time you get cracks, bowing, or one corner that drops.

The good news is the repair matches the problem. You don’t fix everything at once.

Cracks that leak come first. A hairline crack in a poured wall is common and usually not structural. We seal it with epoxy or polyurethane injection that fills the crack front to back. That stops the water and the air. Crack repair starts at $1,000 to $3,000 and carries a 10-year warranty. If it’s only weeping at the floor wall joint, you may not need wall work at all, just interior drainage. We’ll tell you which.

Walls that bow or lean inward are the next problem. Frost and soil pressure can push a wall in. For mild to moderate bowing we install carbon-fiber straps, bonded floor to sill, that lock the wall and stop further movement. That runs $850 each with a 25-year warranty. When a wall has moved more, we use a power brace, a steel beam system, at $1,300 per brace. Severe cases need wall anchors or steel I-beams, and we price that after we see it. There’s no fair way to quote a leaning wall over the phone.

A foundation that’s sinking or settling needs the footing addressed. When a footing drops, the fix is to reach soil that won’t move. We drive helical piers or push piers down to load-bearing strata and transfer the house’s weight onto them. We self-perform structural lifting and helical installs with our own crew. Piers start at $2,700 per pier for the first three, then $2,200 per pier after that and carry a 25-year engineered warranty.

Sagging floors point somewhere else. Sometimes the problem isn’t the perimeter wall. It’s the center of the house. A rotted sill, a sagging beam, or an old post can let your floors dip. We replace lally columns and add floor support starting at $1,300 to $2,500 (10-year warranty), replace sill and beam at $7,000 to $40,000, or build an auxiliary wall, a sister wall beside the failing one, at about $1,350 per linear foot. A full foundation-wall rebuild is rare, and we price that after we see it.

One point worth knowing: if a salesman says you need to dig up the whole outside of your foundation to fix it, be careful. In our field experience exterior excavation jobs tend to fail again in about two or three years. The soil settles right back. The durable fix for water is interior drainage, and the durable fix for movement is repair from the inside.

A note for new construction. We repair foundations, we don’t pour new ones. If you’ve got a brand-new build with an issue, we handle the repair side: cracks, support, piers.

You don’t always need the big job. Plenty of homeowners call worried about a “foundation problem” and walk away with a $1,000 to $3,000 crack seal and a dry basement. That’s a win, and we’ll say so.

Want to know which repair your house actually needs? Get it looked at.

We’ve earned the trust of 5,000+ homeowners in New England. We’re BBB A+ accredited, licensed and insured, and rated 4.9 across 250 Google reviews. Every structural repair is backed by the 603 guarantee.

See the full menu on our structural and foundation repair page, or read up on helical piers, sill replacement, and supplemental support. If water is the real issue, start with basement waterproofing. For radon during the work, see radon mitigation.

For background on how soil and water move against a foundation, the U.S. Department of Energy’s Building America program is a solid neutral source (basc.pnnl.gov). The Insurance Information Institute (iii.org) explains how foundation issues relate to home coverage.

Call us at 603-610-1770 or book your free inspection. Free inspection, free estimate, quote within 24 hours.

Related questions

Is a foundation crack a serious problem? Often no. A thin vertical crack in a poured wall is common and usually just lets in water or air. We seal it with injection from $1,000 to $3,000, 10-year warranty. Horizontal cracks or ones that keep widening matter more, so get those looked at.

Can you fix a bowing basement wall without rebuilding it? Yes. Carbon-fiber straps stop mild to moderate bowing at $850 each (25-year warranty), and a power brace handles more movement at $1,300 per brace. Rebuilding the whole wall is rare. We price that after we see it.

How do you fix a foundation that’s sinking? We drive helical or push piers down to stable soil and transfer the house’s weight onto them. We do this with our own crew. Piers start at $2,700 per pier for the first three, then $2,200 per pier after that with a 25-year engineered warranty.

Do you fix sagging floors? Yes. That’s usually a center-of-house issue: a rotted sill, a sagging beam, or a failed post. We add floor support and lally columns from $1,300 to $2,500, or replace sill and beam at $7,000 to $40,000.