How to seal or stop water coming from earth in my home

Stop water at the floor wall joint with full-perimeter interior drainage that catches it and pumps it back out, rather than by sealing the wall and hoping. A waterproofed basement runs about $3,000 to $30,000 and comes with our Forever Dry System, 100% guaranteed to be dry for life! For a dirt or crawl space floor, the fix is encapsulation, around $3,000 to $25,000.

Here is what is actually happening. When your house was built, the crew dug a big hole, set the foundation, then pushed the dirt back in around it. That pushed-back dirt is called disturbed backfill. It is looser than the packed ground around it. So it drains slow and holds water against your wall. Rain and snowmelt sit right there. Then the water finds the weakest spot and comes in.

In New Hampshire we get a second problem. Frost heave. When that wet soil freezes, it swells and pushes on the wall. Over years that can crack it and shove it inward. Cold ground plus wet backfill is hard on a foundation.

So where does the water get in? Almost always the floor wall joint. That is the seam where your wall meets the slab. It is the lowest point and it is never sealed tight from the factory. Water rises up under the slab and finds that seam. You might also see it weep through a crack or through the block itself.

You cannot stop this from the inside by painting the wall. Sealers and coatings hold for a little while, then the water pressure behind the wall pushes them right off. The water has to go somewhere. So you give it somewhere to go.

That is what the Forever Dry System does. We cut a channel along the inside perimeter of your basement and lay interior drainage at the footing. Any water that comes in drops into that channel instead of onto your floor. It runs to a sump pump and gets pumped back outside. We size the pump at 1/2 hp for every 120 feet of drain. Then we hang a 12-mil vapor barrier on the walls so wall seepage drains down into the system, and we set a dehumidifier to pull the damp out of the air. Basement done. Dry for life, and the warranty transfers if you sell (conditional on nobody else touching the work).

A quick word on the outside fix, since people ask. We do not dig up your yard to waterproof the wall from outside. Nik, one of our owners, has watched exterior excavation jobs fail in about two to three years. That is our field experience, not a stat. The water table and the frost just beat it. Interior drainage is the durable fix, so that is what we install.

The Forever Dry System is for basements. If your water is coming up through a dirt or crawl space floor, you need crawlspace encapsulation instead. That is a 12-mil wall vapor barrier plus a 20-mil floor vapor barrier, with dimpled drainage matting under the floor barrier, spray-foam-sealed seams, a dehumidifier, and a sump. It seals the earth off so ground moisture stops coming up. The Department of Energy notes that up to about a third of a home’s heat loss can come from an uninsulated foundation or crawl space, so a sealed crawl often feels warmer too.

What drives the price? Square footage of perimeter, how many pumps you need, whether you want a backup, and how bad the water is when we get there. A basement runs about $3,000 to $30,000. A crawl space runs about $3,000 to $25,000. We do not guess. We come look, then quote within 24 hours.

You may not need everything. If your water is one small crack and the rest of the basement is bone dry, you might just need a crack injection, around $1,000 to $3,000. We will tell you that. We would rather fix the one crack than sell you a full system you do not need yet.

One more thing worth checking while we are down there. If your house sits on a dirt or fieldstone crawl, that same earth that lets water up can let radon up. Radon is a gas from the ground. The EPA action level is 4.0 pCi/L, and they suggest you consider fixing between 2 and 4. We can test for it and install a system that pulls it out from under the slab or under a crawl membrane.

A charged backup battery on your sump keeps the pump running through an outage. That is real protection during a storm and a power outage. We offer a battery backup as part of the system.

Want it looked at? Call us at 603-610-1770 or book your free inspection. The inspection and the estimate are both free, and we quote within 24 hours. Read the 603 guarantee and our basement waterproofing and crawl space services pages for the full picture. If you have a wall that is cracked or bowing, see structural and foundation repair too.

Related questions

Can I just paint a waterproof sealer on my basement wall to stop the water? For a while, maybe. Then the water pressure behind the wall pushes it off. The lasting fix is interior drainage that catches the water and pumps it out. See basement waterproofing.

Water is coming up through my dirt crawl space floor. What stops that? Crawlspace encapsulation, around $3,000 to $25,000. A 20-mil floor barrier over dimpled matting, sealed seams, a dehumidifier, and a sump seal the ground off. See crawl space services.

Why does water pool against my foundation after it rains? The soil packed back around your foundation when the house was built drains slowly and holds water against the wall. That water finds the floor wall joint and comes in. Interior drainage handles it for good.

Do you dig up the yard to waterproof from outside? No. In our experience exterior digs fail in a couple of years here. Interior drainage is the durable fix, and it comes with our Forever Dry guarantee. Call 603-610-1770.