View Full Version : Backerboard bath walls

05-23-2007, 06:22 PM
How important is it to use backerboard when installing tile for a shower. Would it be ok to just go over the current gypsum board with tile.

My house is 50+ years old and i plan to sell soon anyway and sure it will be torn down within 10 years.

05-23-2007, 06:40 PM
You can do that, and it'll probably last a few years if you do a good job of grouting and caulking. But nowadays CBU is what's used. It doesn't rot out like gypsum board.

05-23-2007, 07:07 PM
Installing tile on drywall is not an approved method in a shower. You'd legally have to divulge that during the sale as a defect as I understand it. Might as well do it right, it doesn't cost much more - probably less than $50. Put a vapor barrier behind it - either plastic or roofing felt.

05-23-2007, 08:15 PM
what they said. Eric and Jim.

Cement board and plastic sheet behind it between it and the studs. Hang the plastic so it falls down just inside the tub flange. Then, drips and seepage leak into the tub and not into the studs. Cut the cement board a bit short so that it leaves a gap there; no good having it wick water back up when shower water hits the tub-wall junction. The tiles cover that gap anyway; they overhang. Then you caulk the last little bit of space between the tiles and the tub.

How did you end up with "the current gypsum board" in the first place? You could unscrew it and use it for something else.


06-15-2007, 07:25 PM
Do you overlap the Vapour barrier into the flange of the tub if you are on a exterior wall (northern climate) or do you run it to the floor? Also do you run the vapour barrier on the other two interior walls to the floor or to the tub flange or do you even need the vapour barrier there? I am using hardibacker board!
Help!! I am a newbie at this!!

Thanks in advance!!

06-15-2007, 09:45 PM
Inside the tiling flange. Several threads this week cover it very well. Search and ye will find.