Replies

1. 
   jjkaz | Apr 27, 2005 09:16am | #1

   I'm not a tile guy, but I've made plenty of mis - takes in the past by doing stuff like this. The problem comes in with the USE factor. You can tile over almost anything if it's strictly decorative, but as soon as you introduce variables like water, and heat you're asking for trouble. I'm just finishing up with an epoxy floor in a commercial kitchen butcher shop and pot wash area. The scope of the job was to remove failing quarry tile on the floor and cove base, prep the floor, and install a seamless epoxy mortar floor. The existing walls were a combination of ceramic tile and stainless steel, As we removed the cove, we discovered cement backer board, green board, wood studs and metal studs, and total wall and framing damage (including some of the cement backer board) from water that had entered not only through the failing floor, but through minor grout cracks and stainless steel seams where the silicone caulk had failed. A relatively simple 20 K job by us turned into a 60 K bill for the owner. Now, this is truly extreme USE, with 7/24 pot washing going on and the butcher shop being hosed down every day, but the vast majority of the damage could have been prevented with proper material selection (including substrates) and attention to DETAIL during construction. I'm sure some people will write in saying that such and such could work, but if you're designing for a do it yourselfer client who can't handle greenboard, what quality of work is he going to perform on the rest of the stuff? My suggestion would be to include drawings and/or instructions on how to handle all those nasty details, and hope that when this guy's work starts falling apart he dosen't blame it on faulty design.

1. 
   tea | Apr 27, 2005 03:55pm | #2

   " but if you're designing for a do it yourselfer client who can't handle greenboard, what quality of work is he going to perform on the rest of the stuff? "

    

   He's a friend and neighbor and stubborn! He's also super stingy and really doesn't want to hire help. I don't think a kitchen back splash is likely to get very wet, though the area behind to the stove might get hot. He's a decent carpenter, but is a shortcut kind of guy and definitely one who thinks the building code is out to get him. I just keep telling him there's a $1500 fine in our town for doing work without a permit. :-)

1. 
   HealeyBN7 | Apr 28, 2005 05:57pm | #12

   " He's also super stingy and really doesn't want to hire help."

   Maybe he will change his mind when he prices the plywood.  Last time I looked there isn't a sheet in the house that is cheaper than drywall.

    

   It's too expensive to be cheap.

2. 
   TMinor | Apr 27, 2005 04:05pm | #3

   The plywood will work just fine. Just make sure the cabinet installers aim their mounting screws toward the studs and not in the plywood.

    

   -Chief of all sinners
3. 
   Frankie | Apr 27, 2005 05:19pm | #4

   Plywood is fine. Modern home ranges don't produce the heat required to ignite wood - any wood - in a backsplash location, especially when it's behind tile. I would recommend that he use 3/4" plywood. This way the entire sheet of plywood can accept screws to mount the cabinets, thus elimnating the need to locate the studs when hanging. That's usually the biggest PITA during installation We do this fairly regularly. Some installers just use a 6"-*" strip of plywood along the wall, so a full sheet is do-able too.

   As for the tile adhering to the plywood: Not a problem. Just use a modified thinset. This is a thinset that has polymers added to the mix for superior adhesion. Custom Building Products make s a few. They are available at any of the big boxes.

   The plywood doesn't even have to be ext grade but CDX is usually the cheapest.

   Frankie

4. 
   DonK | Apr 27, 2005 06:45pm | #5

   Tea - My Dad redid our kitchen in the 50's with the same concept in mind - All the walls behind the cabinets were done with 3/4 tounge & groove. When I redid the room, my only problem was snaking new outlets. I went over the t&g with gypsum. It does make cabinet hanging a breeze. But make sure your buddy checks out the glue if he's going to tile right over the plywood. I know of litigation a few years ago where all the showers in an entire hotel in Jersey had to be retiled, and one issue was the substrate. Glue manufacturer (a national company) said plywood was absolutely unacceptable as a tile substrate because of the amount of expansion/contraction

   Don.

1. 
   tea | Apr 27, 2005 09:56pm | #6

   "Glue manufacturer (a national company) said plywood was absolutely unacceptable as a tile substrate because of the amount of expansion/contraction"

   I don't understand how that could be as tiles are laid on plywood subfloors all the time, but I will keep it in mind. I wouldn't put plywood behind a shower, I bet the expansion was caused by the wood getting wet.

1. 
   DonK | Apr 27, 2005 11:08pm | #8

   My situation involved a Type 1 glue. Today, with a thin-set it might be different. If I were the architect spec'ing out the products (glue-backer-tiles), I know I would read the limitations first on all of them, just to make sure...

   Don

2. 
   CapnMac | Apr 28, 2005 12:25am | #9

   as tiles are laid on plywood subfloors all the time

   LoL!

   Use the Search function and put "slip sheet" in--you may get an eyeful on floor tile installation.

   The only other search term that would get more opinions would be just searching CBU and floor or cement board and floor, or some combination of those.

   Which does not change the fact that you are right, tile will go on plywood.  I'd use a bonding agent over the raw ply, but that would be a personal preference.

   Now, since the dude is tight and does not want to fuss with d/w; why not just use a full-height laminate splash?  That's cheaper by far than tile, and the contact cement is not going to care about plywood on the wall.  Could also just laminate up the splash before the cabs, too, for that matter, which would permit using post-form c/t, very low-tech.Occupational hazard of my occupation not being around (sorry Bubba)

5. 
   RickD | Apr 27, 2005 10:06pm | #7

   If he can't handle drywall by himself, suggest to him he shouldn't be handling anything by himself :)

   Fire code?  Although it is probably correct that a residential stove won't produce enough heat to ignite a backsplash, it goes without saying that fires do start in kitchens more than other rooms, and I would prefer to have fire-proof rock between the kitchen and the stud bays (chimneys) in my house to at least slow down the spread of fire.

   Why is plywood ok on floors?  You know this, but floors need the strenght of plywood b/c they are carrying a load; gravity is working with whatever is on top of it to keep it glued on.  On a vertical surface, tiles are being pulled down and need more help staying up- 

   Also, walls and ceilings are rock, and fire spreads vertically; the wood in the floor above is protected from fire (theoretically) by the drywall on the ceiling below. 

    

   
   

   ---

   Edited 4/27/2005 3:16 pm ET by RickD

1. 
   tea | Apr 28, 2005 03:43pm | #11

   "Why is plywood ok on floors?  You know this, but floors need the strenght of plywood b/c they are carrying a load; gravity is working with whatever is on top of it to keep it glued on.  On a vertical surface, tiles are being pulled down and need more help staying up- "

   Well that's why I asked. :-)

   I wondered if applied vertically tile would be more apt to fall off. Later post about slip sheets and pointing out that gyp bd. is more dimensionally stable is giving me food for thought...

6. 
   maverick | Apr 28, 2005 12:34am | #10

   >>Am I missing anything here?

   I think so, tell him there's no need to tape behind the cabinets or where the tile goes. And sheet rock is half the price. Sheetrock does'nt expand and contract like wood products do.