A crawlspace with exposed dirt is the most direct radon path a house can have. There's no slab to slow the gas down, just soil, air, and your floor joists. Rural Genesee County homes, cottages, and the additions grafted onto basement houses over the decades put a lot of crawls in our service area, and they get their own system design.
The membrane system, explained
Exposed soil gets covered with heavy-gauge reinforced sheeting. Sealed at every seam, sealed to the foundation walls, sealed around every pier and penetration. Turning the crawl floor into an airtight lid over the ground. The suction pipe draws from beneath the membrane, so the soil gas is captured under the plastic and vented above the roof before it ever reaches crawl air, let alone house air. Done properly it's closer to careful tailoring than construction: the sealing is the system.
Combo foundations get one system, not two bills
Part basement, part crawl is the signature Genesee County remodel result, and the right answer is almost always a single engineered system: sub-slab or sump suction for the basement, membrane for the crawl, one fan pulling both, one verification number for the whole house. Two separate systems is how this gets quoted by companies that would rather sell you twice; one integrated system is how it gets built by people who'll be judged by the post-install test.
The side benefits are real on this one
Membrane work incidentally does what crawlspace encapsulation companies charge separately for: it blocks ground moisture, cuts the musty smell that drifts up into the house, and makes the crawl a place you can actually store things. We size and seal for radon performance first. But you'll notice the rest.
Frequently asked
Is a crawlspace system more expensive?
Usually somewhat. Membrane material and sealing labor scale with the crawl's size and how crowded it is. It's also the system we most refuse to quote sight unseen: an honest crawl price requires eyes on the crawl. The number you get is firm.
Can I just put a vapor barrier down myself?
A loose-laid barrier helps with moisture and does little for radon. Unsealed edges and seams leak gas freely. The radon version is the sealing: perimeter, seams, piers, penetrations, then suction under it, then a test that proves it worked.
Every system we install is guaranteed below 4.0 pCi/L and verified by test. See how installation works, what it costs, the towns we cover, or send a test result for a firm quote.