Crawl space vapor barrier in San Luis AZ - a ground cover that stays put

Most people call after a plumber or pest inspector mentions the crawl space, or after they've been down there and seen bare dirt. The price moves with how big the crawl space is, how much stored stuff and debris has to come out, whether old plastic gets pulled first, which sheet goes down and whether the space is vented, since an unvented one adds sealing work. The schedule mostly turns on getting the space cleared and on checking with the city before we start. You get your own number from the on-site estimate, after the space has been looked at in person and we've gone over what it needs. If you're weighing crawl space insulation too, it makes sense to look at both on one visit.

We start by clearing out what's left down there, debris included, because the plastic can't cover ground it can't reach. If anyone has to crawl through to get to a furnace, ducts or plumbing, I'll price a tougher reinforced sheet next to basic plastic, since thin plastic tears where knees and toolboxes drag across it. If nobody ever goes under there, the basic sheet is usually fine and I'll say so. Then we lay the sheet over the ground, overlap the seams, carry it up the walls and around the piers and fasten it so it stays put. Where it runs up the walls, we talk with you about where it stops so there's room left for pest inspections, and one maker's instructions stop it below the wood sill plate, the board the house framing sits on, for that same reason.

A ground cover under the house is a different job from vapor barrier installation in the walls and ceilings above it. If what's really bothering you is a hot upstairs or a high power bill, the crawl space usually isn't where I'd start. Attic air sealing, closing the gaps between your rooms and the attic, is usually the better first job, and I'd rather tell you that than sell you plastic.

Permits in San Luis come from the city's Development Services Department, which issues them for private and public projects across the city, and I won't tell you a vapor barrier skips that step without checking. Before work starts, we check with the city's building office, and if a permit is needed we pull it and set up the inspections. That office inspects buildings and construction sites for the local, state and federal rules on how things are built and what they're built with. If you'd like to ask them yourself, the city's building safety office takes calls at 928-341-8565.

A lot of the crawl spaces we get into have had a plumber or pest crew through them, and the old plastic ends up pushed into piles near the access hatch. We see the same thing on jobs in Somerton and Yuma, so we plan for pulling and resetting old sheets, not only laying new ones.