Is there anything that should be done to prepare the surface of new greenboard drywall prior to tiling? This is a bathtub/shower enclosure environment, adults only, no tenants.
I know greenboard is the least desirable surface – cementious backer board being the most desirable – but unfortunately that’s what I’ve got to work with. Owners had already been advised not to proceed this way…
Should I prime or paint, or apply some sort of membrane? BTW, I will not warranty the work because of the substrate, nonetheless I do want to maximize the durability of the work.
Replies
No, you don't "got" to work with it. It's not right, and you have the superior knowledge that won't get you off the hook when things go bad.
You're absolutely right, I don't 'got' to do it. Thanks for that.
But I'd like to and would spell out in writing the problems which are likely to occur, and why, including that the work is not warranted because of the backing.
Context: The homeowners are planning on selling their house in 3 year's time, so they've got a limited time horizon. If this thread does not yield a method by which I can get reasonable longevity (say 5 yrs.) with greenboard, I'll suggest tearing out the drywall and replacing it with backerboard. If that's not acceptable to them, I'll simply turn the job down.
What I'm looking for is a way to get 5 years out of the installation.
What I'm looking for is a way to get 5 years out of the installation.
And then you'll be back and repair/replace for free, right? Sorry, but that's wrong. You're screwing the next owner for what? Again, if you're gonna do it, it should be done right. If not, don't bother telling the next HO you 'repaired' it, he just might take you to court.
Wrong attitude, IMO. You should fix a shower/tub to last 15-20 years or more by doing the best you can with the most appropriate proven materials available. I don't think DW should even be considered in this instance.
Sorry, touched a nerve, there.
I never met a tool I didn't like!
so you are willing to help the current owners screw the buyers in three years or so?
"I will never surrender or retreat. " Col. Wm. B. Travis, The Alamo, Feb. 1835
But I'd like to and would spell out in writing the problems which are likely to occur, and why, including that the work is not warranted because of the backing.
Why would you "like to"?
Because it will be quick money and you won't have any call backs because you're making it clear up front that you aint guaranteeing shid?
Becaue in three years the people who own the house by then won't know it was youwho screwed 'em?
Maybe they'll call you to 'fix it right" and you can complain about the hack that did the job to 'em and tell 'em how you're now fixing it up 'right' for 'em.
Edit: after I wrote this I finished reading the thread and saw your response to others who posted along the same lines. Still doesn't change my opinion of what you are doing.
"I will never surrender or retreat. " Col. Wm. B. Travis, The Alamo, Feb. 1835
Edited 12/4/2004 12:21 am ET by intrepid_cat
Thanks guys - you've given me many good reasons (short-term and long-term ones) not to do it, and have convinced me of the folly of tiling over DW. Either I convince the owner to go with cementious backer board, or he'll have to find someone else.
Thanks for being persistent.
I assume you're going to use tile mastic rather than thinset? If you make sure that you've COMPLETELY covered the board with mastic then that will seal it fairly well. Little holes in the mastic will let water in.
Of course, eventually the mastic will dry and crack, but that won't be for several years in most cases.
Next week I start on a BR reno with a tiled shower stall. The subfloor is rotted away from the leakage. The base is a mud job, but the walls are tiled drywall. the base to wall joint is in tatters from the water damage to the DW. Seen way too many similar installations to even think about using DW (green, white, or any other color) in a moist area. Why risk it? Again, it's only a matter of time...
I never met a tool I didn't like!
Yes, mastic. Do you think prepping the greenboard with paint would help or hinder adhesion or the mastic curing process?
U can't be serious about using mastic in a shower.
then again ... over green board ... maybe you can.
Have you actually priced backerboard ...
not exactly diamond shopping, ya know.
OK .. best way to install green board and mastic in a shower ....
first light a match ... then ....
or ... how about buying some 1/2 backer board and a bag or two of thinset?
Jeff Buck Construction
Artistry in Carpentry
Pgh, PA
I guess I don't understand. You know this is the wrong material for the application, but you're going to proceed with it anyway? Why not substiture cbu for the green stuff? Is it budgetary, or availability constraints? Doesn't make sense.
Greenboard or cardboard, neither were designed to be tiled in a moist area. Failure is certain, the only variable is time. Probably the most vulnerable part is the bottom of the sheets, which will degrade due to any moisture, creating a mold problem and tile failure.
I know you posted looking for answers, but in this instance, the only true answer, IMHO, is to do the right thing and install the tile with an appropriate backing material.
Good luck.
It is budgetary and longevity related - you know the drill - the house will be sold in 3 years so "why spend the money and effort..."
Plus he's going on his experience, which is that his 24 y.o. house had just such a tiling installation (mastic on drywall) and it survived 24 years and 2 kids (who've now moved away). A miracle no doubt. But it is hard to go against a guy's real life experience, to have him spend more money for a 'better' job that he feels he will never get the benefit of.
He showed me pictures taken during the demo, and sure enough, there was almost nil water damage. So he went ahead and installed greenboard on the original studs which were also sound. Now it's my turn to have a go - or not.
Thanks for your imput.
Edit: No, I would not repair or replace for free. But you're right, this is certainly not the best way to go. What's your take on the context I outlined?
Edited 12/3/2004 11:18 pm ET by Pierre1
I didn't mean to come on all high and mighty, I just think it's wrong. But you gotta do what you are comfortable with. Good luck.
I never met a tool I didn't like!
Here's my read of your situation.........
You're going to go ahead with the tile on the green board, no matter what answers you get here. You want/need the money from this job and will take the easy way out, listening to the homeowner and nodding vigorously as he tells you the previous job of tile over wall board was satisfactory and you've seen and verified it.
Inspite of the answers you've received, you've asked again about prepping the greenboard, knowing that if and when it fails, the current homeowner will be long gone and you will be on to greener pastures.
However, to be slightly helpful here........
Make sure the greenboard is held up from the lip of the tub. Skimcoat the entire surface with mastic and let it dry. Cut the holes for the pipes and fixture oversize so that when the tile is applied with just enough clearance for operation and stem removal there is overlap. Use a good penetrating sealer on the grout. Buy a giant tub of plumber's putty and pack the heck out of the clearance holes AND fill the escutcheon plates so that the putty squeezes out when you place them. Scrape the grout out of all corners before it sets and fill with caulk when dry. Don't use cheap painters caulk.
Come on back and visit some more.
Don't build it wrong.
Les gars ont raison, mon ami. C'est d'la merde pour une douche. Étant donné que ce n'est pas un de tes chalets à location, tu serais tenu responsable pour une vice cachée par les proprietaires quand les prochaines proprietaires intent une poursuite contre eux. Ça vaut pas la peine. Moi, je insisterais pour Durock demi-pouce ou ben je crisserais mon camp.
S'il est cheap à ce point-là, faites-le en panneaux de pre-fini conçues pour la salle de bain. Ouach!
Dinosaur
'Y-a-tu de la justice dans ce maudit monde?
If the homeowner was such a cheapskate that he went with greenboard over cement board in a shower---really, what's the cost difference. More of an installation issue, but again, greenboard is a crap substrate and totally unsuitable for a tile base. You aren't getting enough money to involve yourself with this homeowner. Good luck getting your money from this tightwad.
"Good luck getting your money from this tightwad." Thanks for the warning Brian. Luckily I have not agreed to do the job, so no money is owed.
Leave the green board,put vapor barrior and durarock, tile it with quarter round to hide the edges.Makes for a nice retro look when done with subway style tile.Mike