Their online instructions/diagrams show no use of a vapor barrier. You should, so that any moisture that gets behind the cement board runs into the tub or shower instead of into your wall cavity (causing rot or mold/mildew).
Do you need vapor barrier under laminate? laminate flooring with moisture barrier attached.


Is DuROCK an air barrier?

DuROCK Polar Bear is formulated with a 100% acrylic emulsion. It is a trowel-applied high performance coating for use over wood substrates as both an air and moisture barrier, in particular for the DuROCK PUCCS RMC-1 and InsulROCK RMC-1 Systems.

Does cement board need a membrane?

Contrary to popular thought, tile and grout are not waterproof, and some moisture will penetrate even if sealant is used. … However, if you choose to use concrete backerboard, which is much stronger and more durable than gypsum board, a water vapor membrane must be placed underneath it or a sealant applied on top of it.

When should you not use a vapor barrier?

You may find that vapour barriers are often not required in warmer climates. And, if installed in the wrong climate or on the wrong side of building materials, a vapour barrier can cause more harm than good. This circumstance may prevent water vapour from drying, which in turn can cause rot and mold. (Source: Dupont.)

Is a vapor barrier really necessary?

Vapor barriers protect against mold and rot inside structures by preventing condensation and moisture from building up and damaging building materials. If a home is being built in a very humid climate, a vapor barrier can be an essential source of protection from problems caused by excess moisture.

Does durock need to be waterproofed?

Water does not affect USG Durock® Brand Cement Board, however, TCNA guidelines recommend the use of a waterproof membrane in wet areas.

Do you need a vapor barrier in a shower?

No matter how watertight you think your shower is, moisture in the form of water vapor may still get in. … They are required beneath your shower pan and behind your shower walls. Moisture barriers can be made of polyethylene or a membrane that is rolled directly onto the drywall.

Is a vapor barrier necessary behind cement board?

You should NOT place a vapor barrier BEHIND the backer board. Where, pray tell, would any such collected vapor/water go? Answer:There’s nowhere proper for such moisture to egress. The current best practice is to place waterproofing OVER the backetboard and just UNDER the tile.

Is USG Durock waterproof?

USG Durock™ Brand Liquid Waterproofing and Crack Isolation Membrane. … It is ideal for waterproofing floors and walls in showers and other wet areas, including continuous-use steam rooms.

Should you put a vapor barrier on basement walls?

It provides the best coverage and R-value and and functions as a moisture barrier in and of itself. … But if you use fiberglass insulation batts, then a moisture barrier will prevent water and moisture from entering your walls and creating mold and mildew.

Do interior walls need vapor barrier?

Normally interior walls do not require a vapor barrier, but there are some situations where it is highly recommended. … The paint acts as a vapor barrier as well. A continuous plastic vapor barrier behind the drywall will protect the interior walls of these areas from water damage.

Where should vapor barrier be installed?

Vapor barriers are usually best installed on the side of the wall that experiences the hotter temperature and moister conditions: the inner surface in colder climates and the outer surface in hot, humid climates.

Can I use DPM as a Vapour barrier?

Can you use a DPM as Vapour barrier? You can use a DPM sheet as a VCL and it will do the same job as long as it is sealed correctly and placed in the correct position – on the warm side of the insulation.

What is the difference between a vapor barrier and a moisture barrier?

These two terms essentially refer to the same thing. Moisture barriers and vapor barriers are both building materials designed to prevent water from getting past the barrier. … No vapor barrier is capable of stopping all moisture from passing through.

Is a vapor barrier required by code?

The International Residential Code (IRC) requires either a Class I or II vapor retarder on the interior side of frame walls in climate zones: 5, 6, 7, 8 and marine 4 (see climate zone map).

Can you tile directly over durock?

There is no need to install backer board on a concrete substrate—ceramic tile can be applied right over concrete, provided the surface is flat, smooth, and free of significant cracks.

Can you use durock for shower walls?

Installing cement backerboard is one of the more popular choices for a shower wall substrate. Cement backerboards include Hardiebacker, Durock, Fiberboard, wonderboard, and similar products. … When installed properly they will give you many, many years of durable shower construction.

Do you insulate behind shower walls?

Insulating behind shower walls improves moisture control, which in turn reduces the chances of mold growth. Apart from retaining heat and minimizing condensation, insulating behind shower walls also provides better acoustics by reducing annoying sounds from outdoors or between rooms.

Do you need a vapor barrier with Redgard?

If you are using a topical waterproofing membrane such as a liquid like redgard or hydroban, or a sheet like kerdi, do not use a moisture or vapor barrier behind your substrate.

Do you need to use RedGard over cement board?

You really don’t need the RedGard, but the more protection the better…so go for it. And yes, you can do the boards beforehand. But, hit the filled seams & screws (your weak points) as soon as a panel is ready to give it some time to setup. You’ll have to wait for the fills to dry or at least setup anyway.

What happens if you don't use thinset under backer board?

However, many manufacturers including, both Durock and Hardiebacker not only recommend that you use thinset under their backerboard, but they specify it and will void the warranty on their product if it’s not used. … Thinset is going to create a solid surface under tile and prevent flexing that could lead to cracking.

Can you use drywall mud on durock?

Things You’ll Need Durock Cement Boards are a type of drywall reinforced with cement for a harder surface. This type of wall material can be finished just like ordinary drywall, using joint tape and joint compound.

Can I use drywall mesh tape for cement board?

Apply Mesh Tape Paper tape simply won‘t hold up on cement board. Although paper tape generally leads to a cleaner finish on drywall, you can still achieve a smooth look if you use mesh tape on a drywall/cement board joint. Use this self-adhesive joint tape where cement board and drywall meet.

What Thinset should I use under durock?

Apply latex-fortified mortar or Type 1 organic adhesive with a notched trowel. Hold trowel at an angle to maintain uniform thickness.

Which is better Hardibacker or durock?

HardieBacker is also the go-to choice when it comes to countertops and tile. Durock is too abrasive and can damage vinyl, porcelain, and enamel. HardieBacker does not contain any course materials, so it is the preferable choice. It has a warranty that extends over the use of vinyl tile applications.

Does it matter which side of durock faces out?

When installing USG Durock® Brand Cement Board Panels with EdgeGuard, does it matter which side faces out? No, it doesn’t matter. … The purpose of the dual surfaces (one smooth side, one textured side) on USG Durock® Brand Cement Board is to better receive mastic and thin-set mortar.

Does basement floor need vapor barrier?

If you have a concrete floor that’s in continuous contact with a source of moisture, you’re going to have problems. This is why a vapor barrier under concrete is essential. Vapor barriers are a way to keep moisture from getting into the concrete. Note: A vapor barrier is not the same as an underlayment.

Should I use plastic on basement walls?

Should I use visqueen or plastic sheeting on the framed basement walls? No you should not, as plastic will prevent moisture from moving through the wall and will lead to mold and damage.

Do I need a vapor barrier in my garage walls?

Yes it is needed is you want to insulate and will be using some form of heat / ac. The vapor barrier only needs to cover the insulated area.

What mil plastic should be used for a vapor barrier?

Crawlspace Vapor Barrier Materials Reinforced polyethylene plastic sheeting (poly) comes in a variety of thicknesses and strengths. A 6 mil thick poly is commonly used as a vapor barrier and offers short-term savings to the homeowner.

Do you need vapor barrier with Rockwool?

Note that rock-wool insulation only comes un-faced, meaning there’s no kraft-paper or foil barrier. Depending on the situation, you may need to install an independent permeable membrane to serve as a vapor barrier.

Where does vapor barrier go under concrete?

In California they place sand between slabs and plastic vapor barriers—in Florida they don’t. Almost everywhere (except “California”) that slabs are placed on the ground—a plastic sheet—a vapor barrier—is located directly under the concrete slab and on top of the ground (Photograph 1).

Can you put a vapor barrier over concrete?

You’ll typically need a vapor barrier if you’re installing flooring over concrete. … Therefore, because concrete is porous, it’s a good idea to install a vapor barrier over your concrete subfloor before installing your flooring.

What is the difference between DPM and Vapour barrier?

While damp proof membranes are used under floors to stop damp rising up into the building, vapour control membranes prevent moisture from inside the building creeping into the walls and accumulating in the insulation cavities.

Is damp proof membrane a Vapour barrier?

Vapour Barriers A vapour barrier is a damp proofing product that is attached to a wood floor underlay and is intended to reduce the passage of moisture. It is important to state that vapour barriers are not Damp Proof Membranes and shouldn’t be considered as such.

Is breathable membrane a Vapour barrier?

VCL is a collective term for materials used to control the passage of moisture So in theory, it can be used to describe both breathable membranes and Vapour Barriers which are 2 very different materials. However, you will usually find that VCL is used specifically to describe a vapour barrier.