Cold floors over the crawl space or a damp spot at the foundation? A thin, dense layer of foam stops the draft and blocks moisture.
Closed-cell foam insulation is a dense spray foam we put on crawl space framing, rim joists, rooms over the garage and other tight or damp spots in San Rafael homes, so one thin layer stops drafts and blocks moisture where other insulation would come up short.
Most foam calls I get start with something you can feel. The floor over the crawl space is cold, the room over the garage won't hold heat, or the rim joist, the band of wood that sits on top of the foundation, looks damp. Those spots usually have little room and some moisture, which is where batts and loose fill come up short and closed cell does its best work.
What you'll pay depends on how much area you want covered, how thick the foam goes and how hard the space is to reach. A tight crawl space, a low attic or a finished wall we have to open up all add hours. The schedule turns on prep, any old insulation that has to come out first and the time the house needs to air out before you move back in.
I go into the space before I put anything on paper, so the estimate you get is written for your house and not for an average one. If I find something that has to be fixed before foam goes on, like wet wood or old insulation that's gone bad, I'll show you and tell you what it takes.
Closed cell costs more than most insulation, so it should go where it earns its keep. These are the spots I look at first, plus the one where I'll usually steer you toward something else.
Crawl spaces are often damp, and the rim joist is where a lot of cold air sneaks into the floor. Dense foam sprayed on that framing seals the gaps and insulates in one pass, and it won't sag or turn into a soggy mat the way a batt can down there.
A room over the garage, a sloped ceiling or a short knee wall often leaves only a few inches between the framing. Closed cell gets more insulation out of each inch than looser materials, so it's often the only way to do real good in a cavity that shallow.
In a regular attic with no ductwork up there, foam usually isn't worth what it costs. Sealing the gaps around lights, pipes and the hatch, then topping up with blown-in, loose fill sent through a hose, does the job for less. If your ducts run through the attic, foam starts to make sense.
Here's how a foam job goes from your first call to the walkthrough at the end, and who you'll be dealing with along the way.
Call (628) 234-2144 or use the form and tell us which rooms or spaces are bothering you. We'll get back to you and set up a time for me to come out.
I go into the attic, crawl space or walls and look for anything that has to be fixed first, like old insulation that's wet or full of droppings. Then I write up the estimate for the work.
If you go ahead, we handle any permit the job needs, prep the space and seal what has to be sealed before the foam goes on. You'll be out of the house while we spray and while it airs out.
Before we pack up, I walk you through what we sprayed, what we sealed and anything worth keeping an eye on later. Your family comes back once the house has fully aired out.
We use closed cell where moisture is a worry or there isn't much room, because a thin layer stops both air and water. Walls are where I slow down. Before foam goes on a wall, I look at how that wall dries, since closed cell won't let it breathe. If a wall needs to dry out through the side we'd be covering, foam is the wrong pick there, and I'll tell you so.
Order matters more than the foam. Old insulation that's soaked or full of droppings comes out first, because spraying over it keeps the problem in your house. Wet wood gets looked at, gaps get closed, and only then does our crew spray. Foam is easy to put on and hard to take off, so I want the space right before it goes up.
Closed cell isn't the only foam we spray. Open-cell foam insulation is softer and lighter, and it suits spots with room for a thicker layer or where the wall or roof should still be able to dry. We also bring closed cell to shops, offices and other buildings through our commercial insulation work.
We spray the rim joists, the room over the garage or the crawl space framing, and the rest of the house gets sealing and loose fill. This is what I recommend most, because it puts the expensive material only where it does work.
When the ducts run through the attic or a crawl space stays damp, we spray the whole space so it's sealed as one piece. It costs more, and it's worth it only in those cases.
Tell us which spots you want foamed, whether those walls are open or finished, and any health concerns in the house. We reply within one business day to set a time, and then I come out, look at the space and write up a free in-person estimate. There's no obligation to go ahead.
(628) 234-2144In San Rafael, the city's building permits page covers construction and remodel projects. It's where you find the permit requirements, apply online and schedule inspections online. If you're not sure whether your job needs a permit, I'll find out before we start. When it does, we pull it through the city or county office that covers your address and set up the inspection.
There's also a state rule on the foam itself. Spray foam sold in California has to be listed in a directory kept by the Bureau of Household Goods and Services. Ask us which product we plan to spray in your house, and you can check it against that list before the job goes on the calendar.
We're based in San Rafael and work across Marin and nearby, from Petaluma down to Strawberry and over to Richmond and Berkeley. Most foam calls come from older homes with crawl spaces, rooms over the garage and old insulation nobody trusts, and we handle those the same way wherever you are.
I spent my first years in the trade insulating new houses, where the walls are open and nobody lives there yet. I started this business in 2023 to work on lived-in homes, and those taught me the rest. Leaks and old problems get dealt with first, or the new foam doesn't do much. I'd rather tell you a space isn't ready than sell you a job that won't help.
Our crew does the install, and I'm on site running it, so the person who looked at your house is the one checking the work. We're licensed and insured. In California, the Contractors State License Board treats installing insulation for heat or sound as its own licensed trade, so ask anyone who'll spray foam in your house about their license. Our work is backed by our satisfaction guarantee.
If there's a cold floor, a drafty room over the garage or a crawl space you don't trust, call (628) 234-2144 or send us a message. Tell me which spots bother you most, and that's where I'll start when I come out.
If you have deeper cavities or a wall that needs to keep drying, softer open-cell foam can be the better fit.
For a shop, office or other building with the same drafts and damp spots, we bring the same foam and the same order of work.
The cities below have their own pages on this site. We do the same foam work in other cities nearby too, so if yours isn't listed, call and ask.
In the San Francisco area, closed-cell spray foam usually runs about $1.20 to $1.80 per board foot, which is one square foot of foam an inch thick. That's a regional guide to the market, not our price. Your number depends on how many board feet the job takes and how hard the space is to reach, and you'll see it on your estimate.
Plan on at least 24 hours away, and don't come back until the house is fully aired out and cleaned up, according to national safety guidance. That goes for kids and pets too. Book a night somewhere for everyone, and treat a fully aired-out house as your signal to return.
No. Closed-cell foam won't absorb water, and at typical thicknesses it acts as a vapor retarder, a layer that slows moisture moving through, according to national energy guidance. That's why it suits damp spots, and why I check how a wall dries before we put it there.
Closed cell stops drafts with a much thinner layer. It counts as an air barrier at 1.5 inches thick or more, while open-cell foam needs 5.5 inches, and typical closed cell gives R-6 per inch, a measure of how well it slows heat. On a rim joist, spray foam seals and insulates in one step.
Anyone in the house with asthma, respiratory allergies, a skin condition or a past sensitization to isocyanates, an allergy-type reaction to a chemical used in spray foam, should read the product information carefully before choosing foam. Tell me when I come out, and we'll look at the product together. If foam isn't a good fit, there are other ways to insulate.
Clear a path to the space and plan your time away. Move boxes away from the attic hatch or crawl space door if you can, and line up a place for everyone to stay. Our crew preps the work area itself before anything gets sprayed.
Call (628) 234-2144 or use the form, and point out the spots that feel cold or damp when I'm there, because that's how I tell whether foam is the fix or something else has to be dealt with first.
