On May 24, 11:05�pm, RicodJour wrote:
On May 24, 10:18�pm, muzician21 wrote:

On May 24, 9:48�pm, RicodJour wrote:

BTW, blue board is for plaster, green board is moisture resistant and
should _not_ be used in a shower.

They told me that this stuff - actually kind of a purple color -
replaced green board and is what you would use in a shower stall.

I pulled this off one web site:

"Backsplashes, Shower Stalls & Tub Walls
Water resistant greenboard sheetrock should not be used for walls that
will be subjected to heavy amounts of moisture. This includes but is
not limited to, shower stalls and tub enclosures. Greenboard is water
resistant but not water proof and will disintegrate if it is exposed
to excessive amounts of moisture. It no longer is approved for use
(ANSI A108) as a wet substrate. Depending on moisture conditions, this
product is acceptable for use as a ceramic tile substrate in
residential backsplashes and bathroom wainscotings."

It's made by Gridmarx, says manuf'd to ASTM Standard C1396 and CSA
Standard A82.27

I'd never heard of the stuff, but, again, the HD guy seems to have
been talking out of his ass.
Here's the Gridmarx manufacturer's web page - has nothing at all on
any water resistance properties.http://www.nationalgypsum.com/products/gridmarx.aspx

The standards referenced cover a whole host of wall coverings -
doesn't help clarify things.

If not this, then what should be used in a shower stall?

My personal favorite is Wedi board. �It's very easy to work with, it's
light and it's waterproof. �There are also a bunch of different backer
boards, such as Durock, Wonderboard, Hardiboard, DensShield, Fiberock,
etc.

Do some more research on what you have. �Unless there is another
product also called Gridmarx that is very water resistant, don't use
what you have.

R

use concrete board and mortar all seams before tyling