A moisture barrier is a layer of material — typically 6-mil polyethylene plastic sheeting — installed to block ground moisture and water vapor from migrating into floors, walls, or crawl spaces.
In practice
You'd see this when CRM Services is installing LVP flooring in a slab-on-grade home in Salmon Creek, WA.
Why it matters
Highly relevant in the Pacific Northwest climate for any ground-level flooring project.
Common questions
Do I need a moisture barrier under my new flooring?+
It depends on the flooring type and what's below it. LVP and laminate over concrete slabs almost always require one.
What's the difference between a moisture barrier and waterproofing?+
A moisture barrier slows vapor transmission passively. Waterproofing stops liquid water under pressure.
Need this done right?
Talk to a real contractor.
Free onsite consultation and a line-item estimate you can actually read.