Crawlspace Insulation & Air Sealing
Cold floors and drafts in a southwest Colorado home usually start under the house. We insulate crawlspace walls and rim joists with closed-cell spray foam, and we encapsulate the crawlspace when it needs a sealed ground liner.
Why cold floors start in the crawlspace
The floor you walk on is the lid of the crawlspace. If that space is open to outside air, the floorboards sit over winter air all season, and no amount of rugs fixes it. The rim joist — the band of framing at the edge of the floor — is usually the worst of it, because it faces the weather directly and it's rarely insulated well.
Houses around Pagosa Springs, Pagosa Lakes, Bayfield, and Durango sit through long, cold winters and plenty of snowmelt. A crawlspace that was fine in a milder climate reads as a cold floor and a draft at the baseboards here. The fix is down there, not in another layer on the attic.
Closed-cell foam on stem walls & rim joists
We spray closed-cell Icynene on the stem walls and the rim joist. Closed-cell is the right foam here because it's an air barrier and a vapor barrier in one, it stands up to the moisture a crawlspace sees, and it bonds tight to concrete and framing so there are no gaps for air to sneak through.
That one move does most of the work: it stops outside air from washing under the floor and it warms the rim, which is where people feel the draft. It's also one of the smaller jobs we do, and one of the ones homeowners notice first.
Full crawlspace encapsulation
Insulation is half of it. When the ground under the house is bare dirt, moisture moves up into the crawl all year, and that damp air ends up in the floor system and sometimes in the house. Encapsulation closes that off: a heavy vapor barrier sealed across the ground and up the walls, with the stem walls foamed over it, so the crawlspace is separated from the soil and the outside air.
Not every crawl needs it. A dry, well-drained crawl with a decent existing liner may only need the rim and walls foamed. We'll tell you which one you're looking at when we're under there, and we won't sell the liner if the crawl doesn't need it.
Standing water? We'll tell you first
Spray foam and a vapor barrier are not a fix for standing water. If the crawlspace holds water, the drainage problem has to be handled before anyone encapsulates it — otherwise the liner traps it. If we find standing water, wet insulation, or anything that says the water is the real job, we stop and tell you before we do our part.
We're the insulation crew, not the excavator. Pointing you to the right contractor first is part of the walkthrough.
Crawlspace questions
Why are my floors cold if the attic is insulated?
Because the floor is the ceiling of the crawlspace. Outside air moving through an open crawl, and an uninsulated rim joist, cool the floor from below. Attic insulation doesn't touch that.
Do you encapsulate crawlspaces or just insulate them?
Both. We insulate stem walls and rim joists with closed-cell spray foam, and we install full encapsulation with a sealed vapor barrier over the ground when the crawl needs it. We say which after we've been under the house.
What if there's standing water in the crawlspace?
We won't encapsulate over it. Standing water is a drainage problem, and it needs to be fixed first or the liner traps it. We'll tell you what we find and hold our work until the water is handled.
Is closed-cell foam safe in a crawlspace?
It's the foam we use there on purpose. Closed-cell acts as an air barrier and a vapor barrier and it resists the moisture a crawlspace gets. We don't use open-cell below the floor.
How do I know if my crawlspace is the problem?
Cold floors, a draft along the baseboards, or a musty smell downstairs are the usual signs. The free walkthrough settles it — we look, and we tell you if the crawl is the cause or if it isn't.
Book a free walkthrough
We'll get under the house, see what's there, and tell you what it needs. Call or send the form.
