Your crawl space is basically a dirt-floor basement that breathes. In May humidity like we're seeing this week, that's a recipe for disaster.
Moisture rises from bare soil at roughly 10-15 pounds per day in a typical 1,200 SF crawl space. Add our 80% humidity mornings, and you've got condensation dripping off your floor joists by July. That's how you get the musty smell, cupped hardwood, and black stuff growing on your rim boards.
The fix isn't rocket science: 6-mil polyethylene vapor barrier, sealed at seams and foundation walls. IRC code requires it in mixed-humid climates like ours (Zone 3A/4A). We typically charge $1.20-$1.80 per SF depending on access and existing moisture issues.
But here's what most contractors won't tell you — just throwing plastic down isn't enough. You need proper overlap (6 inches minimum), mastic sealant at the perimeter, and decent drainage if you've got standing water issues.
We installed barriers in three Jonesboro homes last week. Two had minor moisture, one had actual puddles after our recent rains. The wet crawl space needed a sump and drain tile first, then barrier — total investment around $3,200 for 1,000 SF. The dry ones? About $1,500 each, done in half a day.
Best time to tackle this is now, before summer humidity peaks. Your AC will thank you, and so will your floors.
Seen moisture in your crawl space? Reply or DM us for a free assessment.