Prepping for tile countertops..

[Scott Parks]

??? for those of you in the cabinet install bussiness.....
I plan on installing granite tile countertop on a bath vanity and was wondering what is a good recomended base to install tile on? I looked at the Tile Dr. website and they use CDX plywood, with dot and dash cuts in it to minimize warping. What does that mean? Does moisture from the thinset cause the CDX ply to warp? Or is this just what happens over time to the ply. It seems to me if it is fastened securely to the cabinet, it will not warp.
Would it be "good enough" to just use 3/4 CDX and apply the tile right on it, or should I use 1/2 CDX and backerboard? Also they suggested a liquid waterproofing membrane over the ply. What kind of waterproofing product would this be? Would Latex primer for mortor work?

I know there are 100's of ways to skin a cat.... hope I'm not opening a can of worms for a long debate on opinion (or who's right)... I'm just looking for a quality long-lasting solution based on one of these two methods. Thanks.

[Steve Clardy]

??? for those of you in the cabinet install bussiness.....
I plan on installing granite tile countertop on a bath vanity and was wondering what is a good recomended base to install tile on? I looked at the Tile Dr. website and they use CDX plywood, with dot and dash cuts in it to minimize warping. What does that mean? Does moisture from the thinset cause the CDX ply to warp? Or is this just what happens over time to the ply. It seems to me if it is fastened securely to the cabinet, it will not warp.
Would it be "good enough" to just use 3/4 CDX and apply the tile right on it, or should I use 1/2 CDX and backerboard? Also they suggested a liquid waterproofing membrane over the ply. What kind of waterproofing product would this be? Would Latex primer for mortor work?

I know there are 100's of ways to skin a cat.... hope I'm not opening a can of worms for a long debate on opinion (or who's right)... I'm just looking for a quality long-lasting solution based on one of these two methods. Thanks.

For the best results with no moisture issue, use the 1/2 cdx with 1/2 backerboard. Then you can use your regular thinset.
If you use 3/4 cdx without a backerboard, which I have done some, and have had no moisture problems, you will have to use a contact cement. Thinset won't stay stuck to wood.

Steve

[Scott Parks]

For the best results with no moisture issue, use the 1/2 cdx with 1/2 backerboard. Then you can use your regular thinset.
If you use 3/4 cdx without a backerboard, which I have done some, and have had no moisture problems, you will have to use a contact cement. Thinset won't stay stuck to wood.

Steve

Steve,
Thanks for the advice. So don't use thinset between backer and ply? Hmm, contact cement and no mortor might be a good idea, but the ply would have to be perfectly flat. What about gel mastic, will it stick to the plywood?

[Steve Clardy]

Steve,
Thanks for the advice. So don't use thinset between backer and ply? Hmm, contact cement and no mortor might be a good idea, but the ply would have to be perfectly flat. What about gel mastic, will it stick to the plywood?

No thinset. It isn't going anywhere. They only use thinset under the backerboard for flooring, to level the low spots. It doesn't stick there very good either.
Just countersink and screw the backerboard to the cdx. Kinda tough getting a nail short enough with a big head to do this. Yes, use flat cdx.
A good mastic will also work. You can stick your tile to the top, then install it on your vanity, then grout it. Or, do the whole thing with it installed. That way it will be flat and snug.
Steve

[Jamie Buxton]

Liquid waterproofing membrane is not latex primer. It is different stuff, and should be available wherever you bought your tile. Another way to go is 15 pound roofing felt, if you have a roll of it around. Staple it to the plywood, then put down the backer board, screwing through the backer board and the felt into the ply. The screw holes in the felt are self-healing enough to keep water away from the plywood.

There are special screws for backer board. Unlike drywall screws, they won't rust when water gets through the grout. They also have nibs underneath the head to help countersink them into the backer boards. You can buy them where you buy the backer board.

On backer board, thinset will really stick the the tiles down well.

[Scott Parks]

So here's the plan. I have a left over peice of 3/4 CDX and left over 1/4" backer from tiling the floor (have a box of backer screws also). Also have some 15# roofing felt in the garage with no use for it. So, guess I'll put it all together and <BAM> should be good to go! Guess I'll have to take pics when it's finally done...

[Ted Shrader]

Scott -

Related (sort of) question. What type of sink will be going in?

Ted

[Scott Parks]

Scott -

Related (sort of) question. What type of sink will be going in?

Ted

Two self-rimmed porcelain sinks kinda like this:

[Dan Mages]

One more thing.... Although it is not 100% necessary, I would reccomend using liquid latex that you will find in the tile section of the Borg. It will give your couter a bit more flexibility.

Dan

[fred woltersdorf]

scott,go to the following link,lots of pro advice on that forum.helped me out big time.

moderator removed a direct link to another public forum - violates SMC Terms of Service.

[Chris Padilla]

Scott,

I put down 12" green marble tiles for my bathroom floor. After carefully cutting away the linoleum and its substrate, I layed down 1/2" thick cement board from DuPont. Hardi backerboard is another name but this is 1/4". Yes, has Jamie said, get the correct screws to go with the backerboard whichever one you choose. I screwed it all down and then mixed up some thinset (thinset is much easier to use for beginners over mastic IMO) and filled in where two pieces of cementboard butted up (I used no tape...just pure thinset). I let that dry 24 hours and then did up the tiles. I back-buttered each tile first, then used a grooving trowel to make the correct-sized notches in the thinset on the floor and then layed the tile.