How much does it cost to fix a leaking foundation?

A leaking foundation costs different amounts depending on what is actually wrong. A single crack injection runs $1,000 to $3,000. A full perimeter waterproofing system to keep a basement dry for good runs $3,000 to $30,000. We price the fix after we see the water, the wall, and the soil, and our inspection and estimate are free.

“Leaking foundation” can mean two very different jobs. One is a crack letting water through a poured wall. The other is water coming up where the floor meets the wall, what we call the floor wall joint. Those get fixed in different ways, and they cost different amounts. So the first thing we do is figure out which one you have.

A crack in the wall

A poured concrete wall can crack and weep water. If the crack is not moving the wall, we inject it. Epoxy or polyurethane, filled from the inside, sealed. That is the lower end of the range at $1,000 to $3,000, and it carries a 10-year warranty on the injection.

If the wall is bowing inward, injection alone is not enough. NH frost heave pushes on a wall every winter, and the soil against your foundation is disturbed backfill, the looser fill that got put back when the house was built. It drains slow and holds water, so it leans on the wall. To hold a bowing wall we use carbon-fiber straps at $850 each or a power brace at $1,300 per brace. Both carry a 25-year warranty on the stabilization. You do not need straps for a hairline crack that only weeps. We will tell you that to your face.

Water at the floor wall joint

If water shows up along the bottom of the wall, or seeps up through the floor, the fix is usually interior drainage. That is the Forever Dry System: full-perimeter interior drainage, a sump pump sized at 1/2 hp per 120 feet of drain, a 12-mil wall vapor barrier, and a dehumidifier. It runs $3,000 to $30,000 and it is 100% guaranteed to be dry for life! That guarantee is transferable, with conditions.

People ask why we do not dig the outside and tar the wall. We have done plenty of basements after someone else tried that. In our experience an outside dig fails in about two to three years, then you are paying twice. Interior drainage is the durable fix, so that is what we install.

When the foundation is sinking, not just leaking

Sometimes the leak comes with a settling foundation. Cracks that step, doors that stick, a floor that slopes. That is a support problem. Helical or push piers run $2,700 per pier for the first three, then $2,200 per pier after that and carry a 25-year engineered warranty. We self-perform our structural lifting and helical work in-house, so the crew at your house is our crew. For a sagging floor inside, lally columns or floor support run $1,300 to $2,500 with a 10-year warranty. A failing sill or beam runs $7,000 to $40,000. A full foundation-wall rebuild is real work, and we price that after we see it.

What drives the number

Length of wall. How much water. Whether the wall is moving. Whether the foundation is settling. A short crack and a wet whole-perimeter are not the same job, so we do not quote a leaking foundation over the phone. We come look, for free, and you get a written estimate, usually a quote within 24 hours. If a payment plan helps, we offer financing through Hearth, subject to approval, and we make nothing on it.

A note on insurance. Most homeowner policies do not cover gradual water seepage or foundation settling, though sudden events can be different. Check your own policy and ask your carrier. The Insurance Information Institute (iii.org) explains what standard policies typically cover.

We serve New Hampshire, Maine, and Massachusetts, and we are trusted by 5,000+ homeowners in New England, with a 4.9 Google rating across 250 reviews and an A+ BBB accreditation. Licensed and insured.

Want a real number for your foundation? Call us at 603-610-1770 or book your free inspection. We will tell you what you actually need, and what you do not.

Read more on our foundation repair and structural and foundation repair pages, see basement waterproofing and helical piers, and check the 603 guarantee.

Related questions

Is a foundation crack always a structural problem? No. A thin crack that only weeps water is usually a waterproofing fix, injected for $1,000 to $3,000. A crack that is widening, stepping, or paired with a bowing wall is structural, and that is where carbon-fiber straps at $850 each come in. We tell you which one you have at the free inspection.

Can I just seal the crack myself? You can patch the surface, but it tends to come back. The pressure from wet backfill keeps pushing water through. A proper injection fills the full depth of the crack and carries a 10-year warranty, which a hardware-store patch will not.

Why not waterproof the outside of the foundation? We do not do exterior excavation waterproofing. In our experience it fails in about two to three years. Interior drainage with a sump and a vapor barrier is the durable fix, and it is what the Forever Dry System uses.

Does insurance pay to fix a leaking foundation? Usually not for gradual seepage or settling, though it depends on the cause and your policy. Read your policy and ask your carrier. The Insurance Information Institute (iii.org) is a good neutral starting point.