Basement waterproofing in New Hampshire runs about $3,000 to $30,000. A single crack you fill and forget sits at the bottom. A full perimeter system with new wall barriers and a dehumidifier, on a big, wet fieldstone basement, sits at the top. Where you land comes down to three things: how much water you've got, how much of the wall is wet, and what your foundation is made of. We'll come look and tell you straight, free of charge.
Why the range is so wide
Two houses on the same street can be a $1,500 crack fix apart or a full-system apart. Same weather, same soil. Different basements.
Here's what pushes your number up:
- How much wall is wet. One damp corner is a small job. Water along the whole perimeter is a full system.
- Your water table. A high water table pushing up under the floor is a different animal than the odd storm leak.
- Your foundation. Poured, block, and fieldstone all behave differently. Fieldstone is the one that takes real know-how, and it's the one we see most in older New Hampshire homes.
- How much floor we open. Interior drainage means cutting the floor around the perimeter. More linear feet, more cost.
None of that is a guess when we're standing in your basement. It's a guess from your couch. That's why the estimate is free.
What the Forever Dry System includes
When a basement needs the real fix, this is it. The 603 Forever Dry System is a full perimeter drainage system, one half-horsepower sump pump per 120 feet of drainage, a vapor barrier on the walls, and a dehumidifier. The drainage catches the water at the floor wall joint, the sump pump sends it out, the wall barrier keeps the block from weeping, and the dehumidifier handles what's left in the air. On a real wet basement, a sump pump on its own is not enough.
Our backup sump pumps are battery backup. When the power goes out in a storm, which is exactly when your basement floods, the backup keeps pumping.
And it carries a transferable lifetime warranty. 100% guarantee you stay dry, or we come back free of charge. The warranty follows the house to the next owner, as long as nobody else has been in there messing with the system.
When you don't need the whole system
Here's the part a lot of waterproofing companies won't tell you. Sometimes you don't need a system at all.
When a full system is out of budget, or the problem is just one crack, fill the crack and don't look back. A single crack repair runs $1,000 to $3,000. If that's all your basement needs, that's all we'll sell you. We're not going to talk you into a $20,000 system to fix a $1,500 problem.
We'd rather tell you the truth at your kitchen table and earn the next call.
Why we don't dig up your yard
You'll see companies that waterproof from the outside, digging a trench around your whole foundation. We don't do it, and here's why.
In our experience, exterior excavation is a two-to-three-year fix. You pay a fortune, tear up your yard, and the problem finds its way back. Interior drainage lasts because it manages the water for good instead of fighting it at the wall. So that's the fix we stand behind, and it's the one we put our lifetime guarantee on.
What makes New Hampshire basements cost more
Basements up here are their own thing, and it shows up in the price.
A lot of older NH homes sit on disturbed backfill, the loose soil packed back around the foundation when the house was built. It holds water against your wall like a sponge. Add a high water table and our freeze-thaw winters, where the ground swells and shifts every year, and you get pressure on the foundation that a house in a dry climate never sees.
Then there's fieldstone. A lot of New England foundations are stacked stone, not poured concrete, and waterproofing one takes a different approach than a modern basement. It's the kind of basement we handle every week.
What it costs, by how much of the system you need
| Your situation | What it usually takes | Typical NH cost |
|---|---|---|
| One crack, otherwise dry | Crack repair, no system | $1,000 to $3,000 |
| Water along part of the basement | Partial perimeter drainage plus a sump | Middle of the range |
| Whole basement wet, high water table, or fieldstone | Full Forever Dry System: perimeter drainage, sump, wall barrier, dehumidifier | Up toward $30,000 |
Every basement is different, and the only honest number is the one we give you after we've seen it. But that's the shape of it: a crack fix at the low end, a full system at the top, and most homes landing somewhere in between.
Frequently asked questions
Does homeowners insurance cover basement waterproofing? Usually not. Most standard policies treat gradual water and maintenance as the homeowner's job, and waterproofing falls in that bucket. A sudden, accidental event like a burst pipe can be a different story. Check your own policy, and don't count on insurance to pay for a wet basement.
Is waterproofing actually worth it? A dry basement protects the thing your whole house sits on, keeps mold and that damp smell out of your air, and holds your home's value. A wet basement only gets worse, never better. So yes, when there's a real water problem, it's worth doing right.
How long does it last? Our interior system is built to last for good, and it's backed by a transferable lifetime warranty. That's the whole reason we do interior drainage instead of an exterior dig that gives out in a couple of years.
Interior or exterior, which is better? For lasting results in New Hampshire, interior. It's why we build every basement waterproofing system from the inside and put our guarantee behind it.
Get a real number for your basement
The range on this page gets you close. A free inspection gets you the actual number. We'll come look, tell you exactly what your basement needs and what it doesn't, and give you an estimate free of charge. No pressure, no treating you like just another number.
Call us at 603-610-1770 or book your free inspection.
