---
title: "Prep Set Go! Moisture Barriers Ep.9"
description: "In this video we will be looking at moisture barriers - what they are, the different uses they can have, and the different types of moisture barriers available. We will also go through how to install moisture barriers correctly."
url: "https://www.rlapolymers.com.au/docs/prep-set-go-moisture-barriers-ep-9/"
updated: "2023-12-06"
category: "Prep-Set-Go Videos"
---

# Prep Set Go! Moisture Barriers Ep.9

[YouTube video player](https://www.youtube.com/embed/PGFxvxZ39Lo?si=Xv4Qu7BFOCv63K8m)

     Description   Transcript

## Description

In this video we will be looking at moisture barriers - what they are, the different uses they can have, and the different types of moisture barriers available. We will also go through how to install moisture barriers correctly.

## Transcript

0:00
 [Music]
 0:03
 Hello and welcome to this new episode of Prep Set Go proudly brought to you by RLA Polymers, in this
 0:09
 video we'll be looking at moisture barriers and specifically when used in flooring applications
 0:14
 we'll look at their importance, various scenarios for their use, discuss the different types,
 0:19
 and provide tips for installation. So let's get straight into it. Moisture barriers play an
 0:24
 important role and are a critical consideration for the longevity of flooring systems, as well
 0:29
 as the health, safety and general well-being of the home and its occupants. Moisture will
 0:34
 wreak havoc on floor finishes left unchecked, so the installation of moisture barriers is
 0:39
 a critical consideration. To truly appreciate the significance and requirement for moisture
 0:43
 barriers, let's begin by understanding how water infiltrates substrates. The most common
 0:49
 and obvious way is through rising damp - that's groundwater permeating through concrete slabs,
 0:53
 often caused by defective below slab or perimeter moisture barriers, or through older slabs where a
 0:59
 vapor barrier may have have not been installed or has broken down. The severity of rising
 1:03
 damp can vary based on a number of factors including sight drainage, groundwater levels,
 1:08
 gradient of the site, and local climate. Rising damp manifests as damp spots or active water
 1:14
 on concrete slabs. The presence of efflorescence or salt damp is another obvious sign of moisture
 1:19
 entry. Other sources of moisture that has the potential to affect floor finishes is through
 1:24
 residual moisture in the substrate. Moisture levels in new substrates are high initially
 1:30
 and recede over time, but can fluctuate due to environmental conditions such as high humidity.
 1:36
 So how can moisture directly affect your flooring system? And what are some of the obvious signs?
 1:41
 These include the breakdown and re-emulsification of flooring adhesives leading to delamination
 1:47
 or lifting of the floor finish from the substrate, warping or cupping of timber floors,
 1:52
 bubbling or blistering of vinyl sheet flooring as moisture vapor gases out and tries to escape,
 1:57
 also the growth of mould and mildew under carpet and vinyl finishes. The dark and damp environment
 2:03
 provides perfect conditions for its growth and propagation and this is always a major concern as
 2:08
 it can directly affect the health and wellbeing of the building's occupants. So when should a
 2:12
 moisture barrier be used? Flooring standards covering the installation of textile and resilient
 2:17
 flooring systems are very clear on the requirement for moisture barriers setting the parameters for
 2:23
 acceptable substrate moisture content and water vapor transmission rates. These standards include
 2:28
 AS1884 for resilient flooring and AS2455 for textile floor coverings each standard details
 2:35
 testing methods to be used for measuring inslab moisture prior to the installation of the flooring
 2:40
 system including ASTM F2170 this is the surface probe method a destructive test that measures
 2:46
 moisture levels deep down into the concrete substrate, and ASTM F1869 and this outlines
 2:53
 water vapor transmission testing which measures the rate in which water vapor escapes the slab.
 2:58
 Around 75 to 80% relative humidity or around 4 to 5% moisture content is a threshold before
 3:04
 a moisture barrier is required to be used. Of course moisture barriers can be applied purely as
 3:09
 long-term preventative or precautionary measures regardless of current moisture levels. Now to the
 3:15
 different types of moisture barriers available, so there are two main types of moisture barriers
 3:19
 used under flooring finishes including sheet systems - these are flexible sheets made often
 3:25
 of materials like polyethylene plastic. They are typically rolled out and installed on on
 3:29
 top of the concrete substrate before floating floor finishes such as laminate or vinyl plank
 3:34
 is installed. And the second is liquid barriers. Liquid moisture barriers include two part epoxy
 3:40
 coatings and are applied directly onto concrete subfloor, they create a continuous seamless seal
 3:45
 against moisture and they're used for floor types that are typically adhesive fixed to the substrate
 3:49
 including timber and vinyl. So we've looked at the two different types of moisture barriers,
 3:54
 sheets and liquids here we're going to concentrate on the liquid moisture barrier varieties RLA
 4:00
 moisture barrier is a two-part water-based epoxy coating designed to provide moisture and vapor
 4:05
 barrier properties, applied to concrete surfaces in a couple of coats it prevents rising damp,
 4:10
 and residual moisture that might be in the substrate to protect the overlaid flooring
 4:14
 finishes. It comes in two parts, equally mixed, and basically just spread on by brush or roller
 4:20
 onto the substrate. Here's some we mixed up earlier so we show you how it's applied. It's
 4:25
 basically applied just by brush or roller, directly onto the substrate, and as I said a
 4:29
 couple of coats, goes on quite easily just like a thin paint type coating, just brushed evenly,
 4:37
 and neatly onto the surface. Allow it to dry between coats, and 24 hours later you can apply
 4:45
 the floor finish over the top. It's important to refer to the manufacturer's recommendations
 4:50
 for the installation of the various moisture barriers, it's also important to refer to the
 4:55
 actual flooring manufacturer's recommendations for the type of moisture barrier they recommend. Thank
 5:00
 you for joining us today for our look at moisture barriers, and the role they play in protecting
 5:04
 your flooring system. Whether you're building a new home or renovating an existing space,
 5:10
 it's crucial to consult with a professional and consider using a moisture barrier in order to
 5:15
 preserve the integrity of your floor finish, and prolong its lifespan, to create a safe and
 5:20
 healthy indoor environment for occupants by preventing mould and mildew growth,
 5:25
 and realizing cost savings by not having to replace moisture affected flooring,
 5:29
 and safeguarding your flooring investment. Remember, prevention today can save you a lot
 5:33
 of headache tomorrow. Thanks again for joining us today, and we hope to see you next time [Music]
 5:42
 Goodbye.