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.

🔨 Construction & RemodelingSimpleAlso: vapor barrier, vapor retarder, moisture membrane

Moisture Barrier

Definition

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.

Common Questions

Real-World Example

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.

Related Services

FlooringExterior Repairs

Related Terms

🔨

Subfloor

The subfloor is the structural layer of flooring nailed or screwed directly to the floor joists. In ...

Back to Glossary