How can a house with a low foundation be prevented from sinking?

A house with a low foundation is kept from sinking by transferring its weight down to stable soil with helical or push piers, then stabilizing any cracked or bowing walls so the structure stops moving. We price pier work after a free inspection, and helical piers start at $2,700 per pier for the first three, then $2,200 per pier after that. The piers do the lifting and holding. The wall work keeps it that way.

Here is what “sinking” usually means in a New Hampshire house. The footing is sitting on disturbed backfill, the looser fill that got put back when the house was built. That fill drains slowly and holds water. Add NH frost heave, and the ground under one corner shifts more than the rest. The house settles. You see it in stair-step cracks, doors that stick, and floors that pitch toward one wall.

Low foundations make this worse for a plain reason. The footing sits closer to wet, freezing soil. Less depth, less margin.

The fix that stops the sinking is piers. A helical pier screws down past the bad soil to a load-bearing layer, then we attach it to the footing and shift the house weight onto it. A push pier does the same job by driving down to refusal. Once the load rides on the pier instead of the soft fill, the settling stops. We do this work in-house and carry a 25-year engineered warranty on helical piers. See our helical pier page and the broader structural and foundation repair hub.

If the floor inside is sagging instead of the outside wall dropping, that is a different support problem. A bad lally column or a tired beam lets the middle of the house drop. We reset or replace floor support with lally columns, and that carries a 10-year warranty. You can read more on supplemental support.

What drives the cost is how many piers, how deep they have to go, and what shape the walls are in. A single corner is one number. A whole wall line is another. Helical piers start at $2,700 per pier for the first three, then $2,200 per pier after that. If a wall is cracked or bowing from the same soil pressure, carbon-fiber straps run $850 each and a power brace runs $1,300 per brace, both with a 25-year warranty on the stabilization. Crack injection for an active leak in the wall runs $1,000 to $3,000.

Not every settling house needs piers. A lot of NH houses have old cracks that moved once, years ago, and have been still ever since. If your cracks are hairline and stable, you do not need piers yet. You may just need the crack sealed so water stays out. The way to know is to measure and watch, which is what a free inspection is for. We would rather tell you to wait than sell you steel you do not need.

A few things quietly help. Keep water away from the foundation. Disturbed backfill drains slowly, so roof water that dumps next to the wall keeps that soil soft. Run downspouts well past the house. Slope the grade away. Inside, if the basement is wet, drying it out protects the structure and the air. Our basement waterproofing is the Forever Dry System, a full-perimeter interior drain to a sump that is 100% guaranteed to be dry for life! That guarantee is transferable on its terms. See the 603 guarantee.

One thing we do not do is dig out the whole foundation from the outside to chase a fix. In our field experience an exterior excavation patch tends to fail in a couple of years. Interior drainage and proper support last.

For the structure itself, the Insurance Information Institute (iii.org) is a good neutral read on how standard homeowners policies treat earth movement and settling, which often is not covered. Worth knowing before you assume insurance handles it. Verify your own policy.

If your house is moving, the move now is a look, not a guess. We come out, measure, and tell you whether it is settling that needs piers or old cracks that just need watching. The inspection and the estimate are free, and we get you a quote within 24 hours.

Call 603 Basement Solutions at 603-610-1770 or book your free inspection. We serve New Hampshire, Maine, and Massachusetts.

Related questions

Will my homeowners insurance pay to fix a sinking foundation? Often no. Standard homeowners policies usually exclude earth movement and gradual settling. The Insurance Information Institute (iii.org) explains the general rule, but read your own policy or call your agent. We can document the structural problem for your records.

How do I know if my foundation is still moving or just settled once long ago? You measure and watch. Old cracks that are hairline and have not changed in years are usually stable and may just need sealing. Active movement shows fresh cracks, widening gaps, and doors that get worse. A free inspection sorts the two.

Do you build a new foundation if mine is too far gone? We do repair, not new builds. We can support, lift, and stabilize an existing foundation with piers, straps, braces, and floor support. For a full wall rebuild or anything larger, we price that after we see it.

Can carbon-fiber straps stop a wall from bowing in? Yes, for many walls. Carbon-fiber straps hold a cracked or bowing wall and stop it from moving further, and they carry a 25-year warranty. Straps run $850 each. A power brace at $1,300 per brace is the call when a wall needs more force. We tell you which one fits after we see it.