Installing Durock for Shower Wall
Hi everyone. I'm new to the forum and it seems there is a wealth of great information here.
I'm currently working on a masterbath remodel and I'm ready to install the cement backer (Durock) for the shower walls. It is a corner shower. The interior wall will be insulated with r-11 unfaced insulation. The exterior wall has the same insulation. My question is should I put a vapor barrier up between the insulation on the exterior or interior walls? When I called USG they seemed a little vague stating that the vapor could cause mold build up if water got behind the Durock but it was common to install the vapor barrier.
The Durock will go up about 6' from the shower floor. I'm using green board for the last 2' of the wall on both walls. I am not installing a vapor barrier behind the green board.
Thanks for your advice,
Installing Durock for Shower Wall - using cement board to avoid the vapour sandwich
Vapour and Mold are nasty realities for many people and many builders around North America.
Seattle like Vancouver is a harsh climate.
Rain. Clouds. More Rain. More clouds. A couple of months of sun and then some freezing rain. Days and weeks of clouds.
For this weather the side affects are for some reason we live longer than the rest of the continent. Some say it's the rain. Some say its the fish. Some say we are more active in the Pacific North West.
One thing for sure is that we have a wack of leaky condos. Poor rain screen designs and are fair share of dodgy builders.
I am mixed in my opinion on vapour barriers and house wraps. I like the concept of the rain screen and the value it adds to drying out a home. I do not think a home should be wrapped up so tight it can't breath but feel it should breath a little bit just to stay healthy.
I have never seen on an exterior wall the level of mold that comes from a failing shower. Never. Often an exterior wall may be bad but to some degree it does breathe from the outside. An interior wall that is getting soaked with no airflow and a constant supply of water makes for a mold pit and nasty business.
Build your showers better. If you think you have mold - check. It's your home and you and your family breathe there every day and every night.
These points brought up above are very useful to deciding the routes to take. How I build an exterior wall here in Vancouver will differ from Jimbo in San Diego, or Tym in Winnipeg or Angus in Chicago.
There is a science to these homes we live in and one building material or system can affect the entire chemistry of your home.
Durock's new Shower System
Check out this recent review for Durock's new Shower System.
Detailed info on Durock's new shower system. Much like Shluter's Kerdi Shower kit. Available October 2013.
Vapor barrier - take a razor and put some slices in it. - Worst Online Advice of 2005
Holy cow is this bad advice! OMG.
Originally Posted by jadnashua
What Jim meant to say is that check with your local building department first. Messing with your home building envelope is high tech stuff. Every state in North America requires it's own vapour barrier codes. Here for example you need a vapour barrier system in place and you can not slice it.
I wonder how many home's Jim has screwed up with this advice. I gues this is what happens when your an expert from everything from lazy susan's to remote control receivers.
Last week during the NTCA's waterproofing course (online) the question of the "Old Vapour Sandwich" was raised. This question was answered by Eric from Noble Company. We (people online taking the remote NTCA training class) where told that right now there is no testing from the TCNA or NTCA into this. There is no test in the short term planned but there is talks about doing one.
If you contact your local building department about this they will tell you that you can not cut your vapour barrier - at least here in Vancouver anyway. This is such a tricky subject and best left to the cities at a local level - go ask city hall!!!
To avoid the vapour sandwich we use cement board. I run the cement board outside the shower and tie it into the drywall assembly by skim coating the drywall to the cement board. I do this step as well since most steam showers we lower the ceiling height to about 84" - this allows about 10" of breathing room above.
These are tricky detailed assemblies and what many of the people seeking out my advice call me about. If you are having a hard time reading through all the crappy advice on this please just call me and we can talk about it.
One way to skirt the issue is to use a two pound spray foam on your exterior walls. My next job coming up should be spray foamed this week. I'll swing by for an action shot if I can.