Greenboard Okay For Tub Surround?

Users who are viewing this thread

PM5K

Member
Messages
151
Reaction score
0
Points
16
Location
San Antonio, TX
My understanding is that it's definitely not okay to use Greenboard for a tile backing. From what I've read it MIGHT be okay if everything is done just so and the grout sealed, but only a very small minority claim this, virtually everyone else says concrete type backerboard.

My understanding also is that USG says the following:

Panels are not intended for use in areas subject to constant moisture such as tub and shower enclosures

Does this mean it should not be used as a backer for a glue up tub/shower surround?

It's my understanding that greenboard was designed to be used in moisture areas like bathroom walls, but not specifically behind surrounds and/or tile.

If it makes a difference this is the greenboard from about fifteen years ago, not the newer type.
 

Jadnashua

Retired Defense Industry Engineer xxx
Messages
32,770
Reaction score
1,190
Points
113
Location
New England
Current codes no longer allow greenboard in a tub surround or shower area. Not all areas use the latest codes. On a wet area, use cbu. While the covering is moisture resistant, the cut edges and screw holes pierce it, and the interior isn't much any better than regular drywall.
 

SacCity

In the Trades
Messages
188
Reaction score
1
Points
0
Location
Sacramento, CA
Website
saccityplumbing.com
To confirm -
Green board is not allowed by code behind tile.

That said when I was way younger I worked for a slum lord, and did lots of bathrooms with green board as a backing for tile.
Using green board we were getting about ten years maximum useful life out of a bathroom remodel. Most were less than that, but these were bathrooms that I did way way back when I was in High School and thats what my father wanted, but then again he was a slum lord.
Michael
 
Last edited by a moderator:

LLigetfa

DIYer, not in the trades
Messages
7,497
Reaction score
575
Points
113
Location
NW Ontario, Canada
Does this mean it should not be used as a backer for a glue up tub/shower surround?
There is a big difference between tile and a one, two, or three piece surround. Schluter claims you can use KERDI over drywall in a shower. A tub surround would seal as well as KERDI.

That sais, I used DUROCK behind the KERDI in my shower. I've also installed a three piece tub surround over existing tile that was set on drywall.
 

Basement_Lurker

One who lurks
Messages
664
Reaction score
1
Points
0
Location
Victoria, BC
plastic/acrylic surrounds are non-porous, so drywall is fine so long as silicone seals are maintained. drywall around a drop-in tub is fine as the walls aren't going to be subjected to constant soaking. Drywall can be used in a shower space if an expensive sealing membrane is painted on and not trashed by a careless tiler. But if you intend on tiling, then a proper vapour barrier with either cbu/mud walls is the only way to go. Some people prefer to use the kerdi system, but IMO it's an overpriced and overhyped system targeted at the DIY crowd.
 

PM5K

Member
Messages
151
Reaction score
0
Points
16
Location
San Antonio, TX
What would you normally glue a glue up type wall surround to?

I'm starting to lean towards Kerdi on top of the greenboard, it's my understanding that there is an exemption in the IRC that allows for this type of usage, I'd then tile over that.

It was under the impression that just because something can create a physical barrier, that doesn't stop water vapor.
 
Last edited by a moderator:

Jimbo

Plumber
Messages
8,918
Reaction score
18
Points
0
Location
San Diego, CA
It was under the impression that just because something can create a physical barrier, that doesn't stop water vapor.

I don't know about that statement. The mistake that has been made in the past was to assume that a grouted tile surface was waterPROOF....which it is not. Glazed ceramic tile is impermeable, but grout is porous..
 

Jadnashua

Retired Defense Industry Engineer xxx
Messages
32,770
Reaction score
1,190
Points
113
Location
New England
Greenboard, for the discussion here, I think, is moisture resistant drywall...

This used to be suggested for use under tile in wet/damp areas, but is no longer approved for that purpose. Other products that may be green are not necessarily the same. In a shower area, unless it is covered by an approved waterproof membrane, you don't want to use drywall or greenboard. And, if you were going to use a waterproof membrane (or waterproof surround), then drywall would still work. Typical greenboard also isn't as stiff as drywall, so when used on a ceiling, generally calls for closer spacing of supports (i.e., 12" OC rather than 16" as used with typical drywall), or it can droop or bow.
 
Top
Hey, wait a minute.

This is awkward, but...

It looks like you're using an ad blocker. We get it, but (1) terrylove.com can't live without ads, and (2) ad blockers can cause issues with videos and comments. If you'd like to support the site, please allow ads.

If any particular ad is your REASON for blocking ads, please let us know. We might be able to do something about it. Thanks.
I've Disabled AdBlock    No Thanks