Why crawlspaces are different
A slab-on-grade or basement foundation gets a straightforward sub-slab depressurization system. A crawlspace needs a different approach, because there’s no slab to core into — just exposed soil under the house, where radon and moisture can move up across the entire footprint, not just through isolated cracks.
A heavy-duty vapor barrier gets sealed across the crawlspace floor and up the foundation walls, closing off that open-ground surface. A suction point set beneath the membrane, connected to a fan, pulls soil gas out from under the barrier before it can rise into the crawlspace or the house above it.
What's included
- Vapor barrier installation — A sealed, heavy-duty membrane across the crawlspace floor and up the foundation walls.
- Sub-membrane depressurization — A suction point and fan beneath the membrane, creating the negative pressure that keeps radon from rising.
- Moisture control — The same barrier that blocks radon also cuts down the humidity and musty air crawlspaces are known for.
Common questions
Will this stop my crawlspace from smelling musty?
Often, yes — sealing off ground moisture is a big part of what causes that smell in the first place.
Does a crawlspace system cost more than a slab system?
It depends on the square footage and current condition of the crawlspace — we quote based on what’s actually down there, not a flat rate.
How do I know the system is still working?
Check that the membrane is still sealed tight at the edges and walls, and listen for the fan’s steady hum. A follow-up radon test is still the only way to confirm your actual number, and we build one into every install.
Have a crawlspace with a high reading?
Get a quote and we’ll walk the space with you.