Shop Products
Houzz Logo Print
sbroadbent_gw

Can I have greenboard in a shower if it is has a mortar bed?

sbroadbent
16 years ago

Can greenboard be used for shower walls if it is covered with a vapor barrier, mortar, and ceramic tile?

My contractor has framed my shower and has screwed USG Sheetrock Mold Tough water-resistant gypsum board, commonly referred to as "greenboard", onto the wood studs. I told him that USG recommends against greenboard in wet areas:

"Limitations: In remodeling applied directly to studs. Panels should not be installed over a vapor retarder or on a wall acting as a vapor retarder unless it will not be tiled or finished with an impervi¬ous paint. Panels are not intended for use in areas subject to constant moisture such as tub and shower enclosures, gang showers and commercial food processing; DUROCK® brand cement boards are recommended for these uses."

http://www.usg.com/USG_Marketing_Content/usg.com/web_files/Documents/Architectural_Spec_Guides/09_21_16_GypPanels_Specification.doc

My contractor says that cement boards are the "cheap" way to do the job. He's going to build a better shower by covering the greenboard with a waterproof membrane, cement motar bed, and ceramic tile.

I have researched online in the library. All designs recommend cement board. I can't find anybody or any reference that supports my contractor's design, which he says he has used for 20 years.

I need advice. Is my contractor's design acceptable? Is there a better way to build a shower?

Thank you for your help.

Comments (3)