Damp dirt, a musty smell or cold floors? We fix what's wrong in the crawl space first, then cover the ground under your house.
Vapor barrier installation in San Rafael, CA means laying heavy plastic sheeting over the dirt floor of your crawl space, which helps minimize the ground moisture and soil gases, such as radon, that rise into the space under your house.
Comfort San Rafael Insulation Services is based in San Rafael, and we work in cities across Marin and nearby, from Petaluma down to Strawberry and over to Richmond and Berkeley. Most crawl space calls I get start the same way. The floors are cold, there's a damp smell, or someone looked under the house and found old plastic torn and bunched up in the corners.
The price mostly comes down to how big the crawl space is, whether you cover the floor alone or seal the whole space, how thick a sheet you pick, and what has to be fixed or hauled out first. The schedule turns on those same repairs and on whether the job needs a permit. I go under the house before I put any of that on paper for you.
Every crawl space is a little different, but these three things decide how the barrier goes in and how long it should be before you're thinking about replacing it.
Federal energy guidance calls for sealing the barrier's seams, and every spot where a pipe or post comes through, with a durable sealant, but only in unvented crawl spaces. So if your crawl space has open vents, the job usually involves less sealing than one that's closed up.
The same guidance calls for covering all of the ground, or as close as you can reasonably get, with the sheet running up the walls, columns and footings. A sheet that only covers the open middle leaves the edges for moisture to come through, so I look hard at the edges when I'm under there.
Barrier plastic is sold by thickness in mils, thousandths of an inch. One cost guide puts a 12-mil reinforced sheet at 15 to 20 years and a 20-mil sheet at 20 to 25 years or more. Underground there's no sun or weather to break it down, so thickness mostly decides when it comes due for replacement.
Here's how a vapor barrier job goes with us, from your first call to the walk-through at the end, and who you'll be dealing with at each step.
Call (628) 234-2144 or fill out the form, and tell us whether your crawl space has vents and whether you've seen standing water or mold down there. That tells me what I'm walking into before I come out.
I come out myself and go under the house. I check for mold, standing water, pest problems and structural damage, see whether the space is vented, and write up an estimate that lists anything that has to be fixed first.
If you go ahead, we handle any permit the job needs. Our crew clears out the space, the repairs get dealt with, and then the barrier goes in, with me on site running the job.
Before we leave, I walk you through what we did and show you where the seams and edges are, so you know what to look at the next time someone goes under the house.
You can cover the floor alone or seal up the whole crawl space, and I'll tell you which one your space calls for. A sealed system brings in more parts, and every one of them is something to pay for and keep running, so I don't push it on a crawl space that doesn't need it.
Whichever way we go, problems come first. Any mold, standing water or pest damage gets dealt with before the barrier goes down, because plastic laid over a wet or damaged crawl space just hides the problem. I'd rather tell you your crawl space isn't ready than sell you a barrier that won't help.
A barrier handles what comes up from the ground. If rooms still feel drafty after that, the leaks are often up top, and attic air sealing closes the gaps there. If the crawl space needs insulation once it's dry and covered, we add it as retrofit insulation, working around a house you're already living in.
Plastic sheeting covers the dirt floor of the crawl space and nothing else. It's the smaller job with fewer parts, and it fits a space that doesn't call for the full sealed system.
The floor sheet plus wall coverage, sealed vents and a dehumidifier, and sometimes insulation and drainage too. It's a bigger job with more to maintain, so it's worth it only when the space calls for it.
We reply to every call and message within one business day. I'll set a time to come out, look under your house and write up a free estimate. There's no obligation to go ahead.
(628) 234-2144In San Rafael, the city's building official issues the permit for work that builds, alters or repairs a building, with exceptions the city lists. That rule alone doesn't settle whether your barrier needs one, so I find out before we start. If it does, we pull the permit and set up the inspection. You can read the general rules on the city's building permits page.
Even work that needs no building permit can still come with conditions from the city's planning, fire prevention or public works departments. New permit applications go through the city's online system, OpenGov. We sort that side out with the city as part of the job, so it's one less thing on your list while the crawl space gets fixed.
Under older houses here, we often find plastic that went down years ago and is now torn, pulled back or missing in the corners, along with stored boxes that have to come out first. We do the same work in San Anselmo and Novato, and in the other cities we serve, so if yours isn't named on the site, call and ask.
I spent my first years in the trade insulating new houses, where nothing is in the way and nobody lives there yet. I started this business in 2023 to work on lived-in homes around San Rafael, where the space under the floor has old plastic, a few surprises and somebody's stored boxes. Those homes taught me that problems get fixed first, or the new material doesn't do much.
I come out myself to look at the job and write the estimate. Our crew does the install, and I'm on site running it, so the person who checked under your house watches the barrier go in. We're licensed and insured. The work is backed by our satisfaction guarantee. When you want someone to look under your house, call (628) 234-2144 or send us the form.
Closes the gaps around lights, pipes and the attic hatch, so the warm air you pay for stops slipping out the top of the house.
Adds insulation to a house that's already built and lived in, such as under the floor once the crawl space is dry and covered.
Besides San Rafael, these cities have their own page on our site. They aren't the only places we work, so if yours isn't listed, ask us about it when you call.
The price comes down to the size of the crawl space, how much of it you seal and what has to be fixed first, so I give you a number after I've been under the house. Full encapsulation costs more than a floor sheet, a thicker sheet costs more than a thinner one, and a tight or packed crawl space takes longer to work in.
The main upkeep is a quick look once a year. The cost guide mentioned above says barriers usually fail from tears, seam tape that dries out, or pipe and post openings that were never sealed, and that yearly visual checks extend the system's life significantly. Look for rips or loose seams, especially after a plumber has been under the house.
The crawl space has to be cleared out and any repairs finished first. Stored items and debris come out so the sheet can cover the ground completely, and old insulation and any damaged plastic get pulled out too. Then the problems I found at the estimate get dealt with, as covered above, before the new barrier goes down.
Laying the barrier is usually the shorter part of the job, and what stretches the schedule is everything that has to come before it. Repairs for mold, water or pests, clearing out old material, and a permit if your job needs one all happen first. Once I've been under the house, I can tell you what's in line ahead of the barrier.
Usually not, because the work happens under the house and we don't need your living space. We do need clear access to the crawl space entrance, so it helps to move anything stored in front of it before we arrive. If something about your job changes that, I'll tell you when I come out for the estimate.
Call (628) 234-2144 or send the form, because one look at the old plastic down there tells you whether it can stay or has to come out before anything new goes in.
