Crawl space insulation in Mount Pleasant SC - warmer floors and a dry space underneath

Most people who call us about the crawl space have noticed cold floors, a musty smell or old insulation hanging loose under the house, and they aren't sure what's safe to do about it. The price mostly turns on how large and how low the space is, whether old insulation has to come out first, whether we treat the walls or the floor, and what it will take to keep the space dry, which is why a crawl space vapor barrier often comes up in the same conversation. The schedule depends on those same things, plus any equipment, flood zone or permit questions that need an answer before work starts. When I come out, I'll explain what I found and what I'd suggest, so you can see which of these apply to your house.

I start by looking for water, because insulation over a damp crawl space only holds the damp against the wood. I check the ground, the vents, the framing and whatever insulation is already down there, and then we decide together whether to treat the crawl space walls or the floor above and how the space will stay dry once we're finished. If a furnace or water heater burns fuel down there, or the house sits in a flood zone, we sort that out before closing anything up. Then our crew pulls out any wet or fallen insulation, does the air sealing by closing the gaps around pipes, wires and ducts, installs the new insulation, which on walls is often closed-cell foam, a dense foam that also blocks moisture, and cleans up after itself.

The floor is rarely the only place a house loses heat. If the rooms still run cold or drafty after the crawl space is done, wall insulation may be the next step, and our air sealing services close the gaps through the rest of the house, from the attic hatch down, so new insulation isn't fighting a draft.

The Town of Mount Pleasant requires a building permit for any construction project worth more than an amount its Building Official sets, or one that needs a structural inspection. Whether your crawl space job crosses that line depends on its scope, so it's something we confirm with the building office before any work starts. The flood rules matter even more under the floor. When a crawl space house is built new or substantially improved, any fully enclosed area below the design flood elevation, the flood height the city's rules are written around, has to let floodwater flow in and out on its own and can't be finished living space. That may limit how a crawl space can be closed off, so if your house is in a flood zone, I'll ask you to call the city's building inspection office at 884-5184 before we begin, and they'll tell you whether the substantial improvement rules affect your project.

Under older and lived-in houses here, we usually find vented crawl spaces, low clearance, ductwork running beneath the floor and batts that dropped years ago. We see much the same under older homes in Charleston and North Charleston, and we handle it the same way, by dealing with the water first and the insulation second.