Crawlspace Radon Mitigation in Iowa City
Crawlspaces require a different mitigation approach: a sealed vapor barrier (membrane) plus sub-membrane suction.
Homes with dirt-floor or partial crawlspaces in Iowa City can't use a standard sub-slab system — there's no slab to suck under. The fix is sub-membrane depressurization.
We install a heavy 12+ mil reinforced vapor barrier across the entire crawlspace floor, sealed to the foundation walls and around any piers, columns, or sump pits. A suction point is cut through the membrane and connected to a fan-driven vent pipe routed out and above the roofline — same as a slab system, but pulling against the membrane instead of the slab.
A properly installed crawlspace mitigation system also dramatically improves the health of the rest of your home: less moisture, less mold pressure, fewer pest entry points, and lower humidity in the floor system above. Many Iowa City homeowners do crawlspace radon mitigation and crawlspace encapsulation as a single project.