What are the best methods for repairing a cracked foundation?

The best repair depends on the crack. A thin non-structural crack gets sealed with crack injection (epoxy or polyurethane). A cracking, bowing, or shifting wall needs structural support like carbon-fiber straps, a power brace, or piers. Most crack injection jobs run $1,000 to $3,000. We give you a free inspection and a quote within 24 hours, so you know which fix you actually need before you spend a dime.

First figure out what kind of crack you have

Not every crack is a problem. A hairline crack from the concrete curing as it dried is common in New Hampshire basements. It can still let water in, but it may not be moving.

A crack that is widening, stair-stepping through block, or paired with a wall that bows inward is a different thing. That one is structural. NH frost heave pushes against foundation walls every winter, and the soil around your house makes it worse. The dirt against your foundation is disturbed backfill, dug out when the house was built and put back loose. It drains slow and holds water, so it presses on the wall. We come look. We tell you which one you have.

The repair methods, from smallest to biggest

Crack injection is the fix for a non-structural crack that mainly leaks. We inject epoxy or polyurethane to fill the full depth of the wall, sealing water out and bonding the concrete back together. Crack injection runs $1,000 to $3,000 and carries a 10-year warranty.

Carbon-fiber straps stop a wall that is bowing or cracking from soil pressure. The straps bond to the wall and hold it from moving further, with no big excavation. Carbon-fiber straps run $850 each with a 25-year wall stabilization warranty.

A power brace handles a wall that needs more force than straps. It is a steel brace system that braces the wall and can be tightened over time to recover some of the movement. A power brace runs $1,300 per brace.

Helical and push piers are for foundations that are settling or sinking, often where you see cracks plus uneven floors or sticking doors. The piers go deep below the disturbed fill into stable ground and carry the weight of the house. We self-perform our helical installs in-house. Helical piers run $2,700 per pier for the first three, then $2,200 per pier after that and come with a 25-year engineered warranty.

Lally columns and floor support fix sagging from below, like a bouncy floor or a beam that has dropped. Floor support runs $1,300 to $2,500 with a 10-year warranty.

For a wall too far gone to stabilize in place, an auxiliary (sister) wall builds a new structural wall against the old one. That runs about $1,350 per linear foot.

A few bigger jobs we do not price over the phone. A full foundation-wall rebuild or replacement, wall anchors, and steel I-beams all depend on what we find. We price that after we see it.

What drives the cost

The method matters most. A single crack injection is the low end. Piers under a settling house are the high end. Length of the crack, how many straps or braces a wall needs, how deep piers have to go to hit good soil, and access to the work area all move the number. That is why we put eyes on it before we quote.

You may not need the big fix

A lot of homeowners call us scared a small crack means the house is failing. Often it does not. If your crack is hairline and not moving, you may only need crack injection to keep water out, and that is it. You do not need piers for a crack that is just leaking, and we will tell you that to your face.

If water is the real issue, the wall may be fine and the basement just needs basement waterproofing instead. Two different problems, two different fixes.

One thing we do not do is dig up your yard to waterproof from outside. In our field experience, exterior excavation tends to fail again in a couple of years. The durable fix for water is interior drainage. We will steer you to the repair that actually lasts.

For the full menu, see our structural and foundation repair hub, our foundation repair page, helical piers, supplemental support, and sill replacement. Whatever we install, it is backed by the 603 guarantee.

For homeowner-side reading on foundation problems and insurance, the Insurance Information Institute covers what home policies usually do and do not cover. The U.S. Department of Energy’s Building America resource explains foundation and moisture building science.

Talk to us

Call 603-610-1770 or book your free inspection. We look, we tell you which crack you have, and you get a quote within 24 hours. Trusted by 5,000+ homeowners across New England, rated 4.9 on Google, BBB A+ accredited and fully licensed and insured.

Related questions

Is a cracked foundation dangerous? Some are, some are not. A hairline crack that stays put is usually cosmetic and just needs sealing. A widening or stair-step crack, a bowing wall, or cracks plus uneven floors point to a structural issue. We inspect it free and tell you which you have.

Will crack injection stop water from coming in? Yes, for a leaking crack. Epoxy or polyurethane injection fills the crack the full depth of the wall and seals it. It runs $1,000 to $3,000 with a 10-year warranty. If water is coming up at the floor wall joint instead, you need drainage, not injection.

Do you fix bowing basement walls without digging up the yard? Yes. Carbon-fiber straps or a power brace stabilize a bowing wall from the inside, no excavation. Straps run $850 each, a brace runs $1,300 per brace. We do not do exterior excavation because in our experience it fails again in a few years.

Can you fix a foundation that is sinking? Yes. Helical or push piers go deep past the loose backfill into stable soil and carry the house. We self-perform the installs and back them with a 25-year engineered warranty. Helical piers run $2,700 per pier for the first three, then $2,200 per pier after that.