---
title: "What Is Moisture barrier? Remediation Glossary | Advanced Environmental Services"
description: "Moisture barrier is a membrane or coating that blocks water vapor moving up through a concrete slab, protecting flooring, adhesives and coatings from blistering..."
url: https://aes.multisites.ai/glossary/moisture-barrier
publisher: Advanced Environmental Services
phone: +1-314-865-2662
quote: https://aes.multisites.ai/contact
---

Concrete

# Moisture barrier

Moisture barrier is a membrane or coating that blocks water vapor moving up through a concrete slab, protecting flooring, adhesives and coatings from blistering, peeling and mold.

Concrete looks solid, but it is porous. Water vapor in the ground can move up through a slab for years. When it meets a floor covering or coating, it can push it off the surface or feed mold underneath.

A moisture barrier stops that path. It can be a sheet under the slab or a coating on top, depending on the project. Graniterock, a materials supplier, advises a low permeance vapor retarder under slabs that will carry moisture-sensitive floor coverings, adhesives and coatings.

For Missouri owners, the key is to test before you finish a floor. Slab moisture can run high even when the surface feels dry. A failed coating costs far more to fix than the test costs.

Moisture also connects to indoor air. Wet slabs can support [mold growth](https://aes.multisites.ai/glossary/mold-spores). If you plan an [epoxy floor coating](https://aes.multisites.ai/glossary/epoxy-floor-coating), ask how the slab was tested and what barrier is in the plan.

[Advanced Environmental Services can helpMoisture barriers](https://aes.multisites.ai/moisture-barriers)

## Related terms

-   [Epoxy floor coating](https://aes.multisites.ai/glossary/epoxy-floor-coating)
-   [Mold spores](https://aes.multisites.ai/glossary/mold-spores)
-   [Concrete grinding](https://aes.multisites.ai/glossary/concrete-grinding)
-   [Polished concrete](https://aes.multisites.ai/glossary/polished-concrete)

## Sources

1.  [Graniterock: Vapor Barriers Under Concrete Floor Slabs](https://www.graniterock.com/product/vapor-barriers-under-concrete-floor-slab)

## Request your custom environmental remediation estimate

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