My cat refuses to use a litter box after she found a dirt crawl space in our house. Is that a problem?

Yes, it can be a real problem, and the fix is crawl space encapsulation, which usually runs $3,000 to $25,000 depending on your square footage and conditions. Your cat found a bare dirt floor and treats it like a giant litter box. That dirt is also a moisture and air-quality issue for the house above it. Seal the crawl space and you close the door on both.

Cats are simple about this. Loose dirt appeals to them. So when a crawl space hatch or vent gap opens up, some cats pick the dirt over the box. The dirt floor is the draw. Take it away and the behavior usually stops.

Here is what is going on under the house. A dirt crawl space breathes damp air all year. In New Hampshire that means humid summers and cold, wet shoulder seasons pushing moisture up through the soil. That moisture feeds mold, wood rot, and musty smells. Air rises through a house, so the air you breathe upstairs is pulling from the crawl space and basement below. A damp, soiled crawl space is not just a cat problem. It is a whole-home air problem.

There is a comfort and cost angle too. The U.S. 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. A sealed, dry crawl holds its temperature better. Your floors feel warmer. Your system works less.

What the fix actually is

For a crawl space we do encapsulation, not our Forever Dry System. Those are two different things. Forever Dry is for basements. A crawl space gets its own build.

Encapsulation means we line the whole space. A 12-mil wall vapor barrier goes up the walls. A 20-mil floor vapor barrier covers the dirt, with dimpled drainage matting underneath so any water has a path. We seal the seams with spray foam. Then we add a dehumidifier to hold the space dry, and a sump if water needs somewhere to go.

When that is done, there is no bare dirt left. Your cat has nothing to dig in. The space is clean, sealed, and dry.

What drives the cost

Crawl space encapsulation usually lands around $3,000 to $25,000. A few things move that number. Square footage is the big one. How much standing water or grading work the floor needs matters. Whether you need a sump, and how much access we have to work in there, also count. We give you a free inspection and a free estimate, and you get the quote within 24 hours. No surprises after.

If radon worry is creeping in here too, a dirt crawl is a common radon path. For a dirt or fieldstone crawl, we install sub-membrane depressurization, which pulls radon out from under the sealed barrier. Radon mitigation runs $900 to $6,000, and most homes land around $1,950 to $2,250. The EPA action level is 4.0 pCi/L, and they suggest considering a fix between 2 and 4. You can test first. A radon test is $50, credited toward the job if you move ahead.

You may not need everything at once. If your crawl is dry and the only issue is the cat finding dirt, encapsulation alone solves it. We will tell you plainly what you need and what you can skip.

Why we do not dig outside

Some crews want to dig around your foundation to fix moisture. We do not. In our experience that kind of exterior fix tends to fail in about 2 to 3 years. The durable answer is sealing and managing water from the inside. That is what encapsulation does.

We are 603 Basement Solutions, based in East Kingston NH, serving New Hampshire, Maine, and Massachusetts. We are trusted by more than 5,000 homeowners in New England, hold a Google rating of 4.9 across 250 reviews, and we are BBB A+ accredited. Crawl space encapsulation carries a 25-year warranty, and the wall vapor barrier is warranted 25 years too.

Want it looked at? Call us at 603-610-1770 or book your free inspection. We will crawl under there, see what your cat found, and tell you what it takes to seal it for good!

Learn more about our crawl space services, our radon mitigation, and the 603 guarantee.

Related questions

Will sealing the crawl space really stop my cat from going under there? Once the dirt is covered with the 20-mil floor barrier and the access is closed up, there is no loose soil to dig in and no easy way under. Most cats lose interest fast. The behavior is about the dirt, so removing the dirt removes the reason.

Is a dirt crawl space bad for my family’s air, not just my cat? Yes. Damp dirt feeds mold and musty smells, and that air rises into the rooms above. A sealed crawl with a dehumidifier keeps that moisture out of the house. See the DOE Building America program on crawl space moisture.

Does a dirt crawl space mean I have a radon problem? It can. Dirt and fieldstone crawls are a common radon entry path. The only way to know is a test. If levels are high, we install sub-membrane depressurization under the new barrier. See EPA radon guidance and NH DHHS radon.

Is encapsulation the same as your Forever Dry System? No. Forever Dry is our basement waterproofing system. A crawl space gets encapsulation, which is a wall and floor vapor barrier, sealed seams, a dehumidifier, and a sump if needed. Different space, different build.