Damp smell, cold floors or wet dirt under the house? We lay a snug ground cover that keeps moisture away from your floor framing.
A crawl space vapor barrier is a sheet of heavy plastic laid over the dirt under your house. The ones we put in around Rohnert Park keep ground moisture and soil gases from rising into the crawl space, where they can get pulled up through gaps in the floor and into your rooms.
The real reason I push for one is the wood. Your floor sits on joists, the beams that carry it, and a rim joist that runs around the edge on top of the foundation. When the crawl space stays damp, that wood is where mold and rot start, and you usually don't notice until a floor gets soft or the house smells musty. A good ground cover keeps that wood dry.
The price mostly comes down to how big the crawl space is, how tight the access is, how much old plastic and junk has to come out, and how many piers and walls the sheet wraps. Water moves both the price and the schedule, because if the yard drains toward the house, that gets sorted first. After I've been under there, I'll show you photos and what I'd do first.
The plastic itself is simple. What makes it work is what's going on around it, so these are the things I look at and talk through with you before anything goes down.
In a vented crawl space, most of the moisture is plain water getting in, from a yard that slopes toward the house, missing drains along the foundation or sprinklers soaking the walls. Plastic laid over that just hides puddles. If I see mud lines or standing water, that gets sorted before the cover goes in, and I'll tell you what I think it needs.
A cover cuts down the moisture coming up from the dirt, but the air down there can still run damp. One university extension guide, written for North Carolina homes, suggests keeping humidity below 60% and thinking about a dehumidifier when it runs higher. A simple humidity gauge in the crawl space tells you where yours sits.
Ask any contractor how the plastic is held to the walls. Federal weatherization guidance calls for physical attachments where they're needed so the sheet stays attached over the long run, because a cover that slumps off the wall leaves bare dirt along the edges. It's a fair question, and I'll show you how we do it.
Here's how a vapor barrier job goes with us, from the first call to the last look under the house, so you know who's showing up and when.
Call (707) 576-6028 or use the form and tell us what's going on under the house, whether that's a musty smell, soft spots in the floor or water you've spotted. We get back to you and set up a time.
I come out myself, go down into the crawl space and take photos. Then we sit down together, and I show you what I found, whether any water problem comes before the plastic and what I'd tackle first.
On install day our crew protects your floors on the way in, clears out the crawl space and fits the cover. I'm on site, or one of our lead installers is running the day.
Before we pack up, I walk through the finished job with you and show you how the cover sits. After that, keep sprinklers off the foundation and take a peek under there after a big storm now and then.
A ground cover protects the wood that holds up your floor, but it can't fix water running under the house. So we start by clearing the space, pulling out old torn plastic, scrap wood and whatever else has collected down there, and I take a hard look at how your yard drains toward the foundation. If the ground is staying wet, I'll tell you that before we sell you any plastic.
Then the crew fits the sheet snug across the ground and up the walls, wraps each pier and overlaps every seam so no bare dirt shows. If you want a moisture layer somewhere other than the crawl space, that's our vapor barrier installation work. Warm air leaking out through the attic pulls air in from below, so pairing this with attic air sealing helps both ends of the house.
Most crawl spaces we get into keep their foundation vents, and once the ground is dry a well-fit cover is usually all they need. It's the simpler job and the one I suggest starting with.
Closing the vents and insulating the walls turns it into a sealed crawl space, which is more work and costs more. Drainage and moisture problems get fixed before that kind of conversion, so we only go there once the ground stays dry.
After you send the form, we get back to you within one business day to set up a time. The estimate is free, done on site at your house, and there's no obligation. I'll go down into the crawl space, take photos and show you what I found before we talk about anything else.
(707) 576-6028The city's Building Division takes building permit applications in Rohnert Park, and contractors and homeowners can apply online. Whether a ground cover by itself needs a permit isn't something I'll guess at, so if it's not clear, we check with the city before work starts. When a job does need one, we apply for it, keep you posted and set up the inspections.
Around here we crawl under a lot of houses on raised foundations, and we see the same few things over and over. Old plastic that's torn or bunched up in a corner, boxes stored right on the dirt, and downspouts emptying next to the foundation. It's the same work we do in Cotati and Santa Rosa, and the fix starts the same way every time, with a good look at where the water goes.
I come out for every estimate myself. I started out hauling bags and crawling through attics for a small insulation crew, and the lead I worked under taught me to look at the whole house before selling anybody anything. That's why I check the yard and the drainage before I talk about plastic. Our crew does the work, with me on site or one of our lead installers running the day.
I opened the business here in Rohnert Park in 2021, and we've been doing this work for five years now. We're licensed and insured. Every job is satisfaction guaranteed. When you're ready, call (707) 576-6028 or send us a message through our form, and I'll set up a time to come take a look.
When moisture is a problem somewhere besides the dirt under your house, this is the work that puts a barrier where your walls or floors need one.
If rooms feel drafty or the power bill keeps climbing, closing the gaps around lights, pipes and the hatch stops warm air from slipping out up top.
We're based in Rohnert Park and work across the cities around it in Sonoma and Marin counties, including the ones below and plenty of others nearby. If your city isn't listed, give us a call anyway.
Yes, federal building guidance says the plastic ground cover belongs down whether the crawl space is vented or sealed. So the cover is part of the job no matter what you decide about the foundation vents. The vents move air through, but they don't stop moisture coming up out of the dirt.
Across the US, a professionally installed crawl space vapor barrier usually costs about $1,200 to $4,000 per job. That's a national figure, not our price. Yours depends on what I find under your house, and I'll give you your own number after I've been down there.
It can help, because a well-installed barrier cuts down soil gases such as radon along with ground moisture, and how carefully it's fit makes a difference. The California Geological Survey says the only way to know your home's radon level is to test for it, so a test before and after gives you a real starting point.
Move anything you've stored in the crawl space out, because the plastic needs to cover the ground completely to do its job. Clear a path to the access hatch and keep pets away from the opening on install day. We'll handle the old plastic and the debris.
If you're 65 or older, California law gives you five business days to cancel a home improvement contract, up from the three days that used to apply. That goes for Rohnert Park homeowners signing for crawl space work like this, so it's worth knowing before you sign with anyone.
Call (707) 576-6028 or use the form, and tell us where the crawl space opening is, whether you've seen standing water and what any old radon test showed, so I can come ready.
