Tiling over damaged drywall with paper missing [Archive] - Ceramic Tile Advice Forums - John Bridge Ceramic Tile


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12-20-2012, 12:54 AM
Hi, I need an advice on drywall (greenboard) repair in my bathroom before installing the new tiles (12 inch).

I removed the old tiles badly and now I have 2 problems.

1) Ripped pieces of greenboard (I repaired some with fiberglass mesh but I wonder if anything more needs to be done).
2) Missing paper (down to bare gypsum).

Do you think this can be repaired and if so how? I really don't feel like installing brand new drywall.

Thank you for all assistance

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Tool Guy - Kg
12-20-2012, 01:24 AM
Hi enzo, welcome.

Is this for a wet area or dry area? And how much damage are we talking? Could you show us a picture?


12-20-2012, 03:28 AM
This is around the shower.

I heard at other forum that the bare gypsum areas have to completely replaced. Is there really nothing else to do?

I'll try to post a pic later.

12-20-2012, 03:55 AM

12-20-2012, 09:44 AM
To add your pics, after you click on " post reply", scroll down and click on "manage attachments". Then you can download the pics from your computer.

It's never a good idea to stick tiles right to sheetrock or even greenboard in a wet area, although it has been done many times. Sticking the tiles directly to the gypsum will be even worse. I would replace the greenboard although if this shower is very old, it's days may be numbered.

12-20-2012, 09:50 AM
Have a look here (http://www.johnbridge.com/vbulletin/showthread.php?t=103369&highlight=Torn+drywall) for answers.

Tool Guy - Kg
12-20-2012, 01:13 PM
Kevin, that thread is for a dry area, not a tub surround like this. So those answers don't apply unless he's going to waterproof the drywall with Kerdi.

Here's enzo's pics:


Enzo, greenboard isn't allowed in wet areas anymore by code in most areas. You could leave the greenboard if you waterproofed it with Kerdi sheet membrane, but your drywall looks pretty rough. The light is kinna flat in the pics and I can't tell if there is bare gypsum or if that's patch. I can't say more definitively with those pics.

If the drywall was too rough or you didn't want to waterproof it with Kerdi, it would be in your best interest to install an appropriate tiling substrate like cement board. And use a moisture barrier behind the cement board (like roofing felt or 6 mil plastic draped over the front of the tub's tiling flange), or apply a waterproofing layer to the front of the cement board (like RedGard or Hydroban). That would put you in good condition to tile your tub surround.


12-20-2012, 06:07 PM

You suggest removing the entire thing, and putting the cement board instead? Kerdi would go behind the board, on the wood frame?

But the house is not that old, from late 90s in fact. Was the greenboard against regulations then?

What is the level of danger here if I just tile over it? Is it that the water will penetrate more easily or will the tiles actually start falling off?

12-20-2012, 06:25 PM
He is saying it would be risky to leave it as it is and cover it with Kerdi. It wouldn't take very long to take down the Greenboard and put cement board in it's place. You have two different ways to water proof the cement board, either put felt paper on the studs behind it or apply a paint on membrane to the front side of the cement board. Don't do both.

Yes, gypsum and dry wall mud turn to mush when water gets to it. If you tile it as it is, moisture will get behind the tiles and then the tiles will start falling off. When the greenboard was new, it at least had the water resistant coating on the surface. As is, you don't even have that now.

12-21-2012, 12:03 AM
Thanks for suggestions. I think I will be replacing the board, probably going for densshield instead of cement.