Vapor barrier installation in Simi Valley CA - a clean, fully covered crawl space floor

Most calls start with a musty smell coming up through the floor, cold floors, or a home inspector's note about bare dirt under a house you just bought. The price mostly turns on how much old insulation and torn plastic has to come out first, how much grading and debris the floor needs, and how much wall and pier surface the sheet has to cover. The schedule turns on whether there's water to fix before we start, and some houses also need crawl space insulation once the ground is covered. Your written estimate lays out each of those pieces, so you can see what's driving your number.

A barrier only works if the ground under it is ready, so once your stored things are out, our crew pulls the old insulation and any old plastic, rakes out rubble and sharp stones, and grades the dirt smooth. That cleanup is part of our price, because one rock left under the sheet turns into a hole the first time someone crawls over it. Then we lay the new sheet over the ground and carry it up the walls and around each pier and column, fastened so it stays put. The install guidance has each seam overlapped like roof shingles, upper piece over lower, and it's worth asking any contractor whether their plan covers the seams, the walls and the piers.

A barrier handles the ground, but heat and drafts usually come in from the top of the house. If rooms run hot upstairs or the power bill keeps climbing, attic air sealing, closing the gaps around lights, pipes and the hatch, is often the next thing I'd look at. In an older house with thin or missing insulation, retrofit insulation adds it to the walls and floors you already have.

In Simi Valley, the city's Building and Safety Division reviews plans and inspects projects under California's building and energy codes. That's the office to ask whether a vapor barrier on its own needs a permit at your address, and I'd check with them rather than assume either way. If your job does need one, we file it with the city or county office that covers your address and meet the inspector on site, so the paperwork isn't on you.

We're based in Simi Valley and work across the cities around it in Ventura County and the nearby parts of Los Angeles County. Under a lot of raised-floor houses, the old plastic is torn, bunched against one wall or buried under insulation that's fallen from the floor above, and we find the same thing on jobs in Moorpark and Thousand Oaks.