Kitchen backsplash over old drywall and joint compound [Archive] - Ceramic Tile Advice Forums - John Bridge Ceramic Tile


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01-17-2017, 01:18 PM
Hi, I am new to this forum and and would appreciate your help, advice and or insights.

My husband and I are redoing our kitchen, replacing ceramic tile with limestone tile. The drywall got pretty torn up in the process of removing the ceramic tile and in an attempt to patch and smooth out the wall my dear husband got the joint compound out. Now first, let me say that my husband is a tradesman (electrician) and is a very talented, resourceful and handy guy all around BUT (bless his heart) taping is not his strength. I cannot convince him to stay away from those projects but anyway our nice flat walls, leave a lot to be desired. The joint compound is thick and uneven all over the place. I could not imagine the MESS if I'd let him at it with the palm sander which is what he wanted to do. I did take a 3" scraper to the really thick areas and the lowest edge but now I'm wondering...

Is the uneven surface going to make installing the tile really difficult or is it negligible?
Will the adhesive stick to the compound? Do I prime it (Kilz) or another oil based primer?
Am I better off installing 1/8" Wedi?
What adhesive would be best if I go directly over the wall as it is? Tile mastic? Mortar system like Kerabond/Keralastic?

I've included some photos of the walls.


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01-17-2017, 05:34 PM
Best and quickest way to handle this, tear it out. If he has an oscillating saw like a Rockwell, cut just below the wall cabinets and just above the base cabinets. Stop just shy of where the tile will end so the joint will be covered by the backsplash. Throw up some new Sheetrock, or hardi and you have a nice flat surface to install on. I would avoid mastic for installing any kind of natural stone, instead find a good modified thinset with a long pot life so you aren't rushing and can take your time installing.

01-17-2017, 06:38 PM
Yeah, it will be far less work and time to just cut that old stuff out of there and install a new panel. If the studs aren't all aligned well, that will also give you the chance to either plane or shim them so the new sheet goes up flat. Yes, trying to tile over that will be problematic, but if you did try, you'd want to use a primer. There are some specifically designed for use underneath tile.

Note, code also would call for either moving the electrical boxes out, or picking up box extenders. The later is easiest, and they are available in numerous thicknesses. The edges of the box should be flush with the new finished wall and if you have a fussy inspector, he will insist. They're cheap and quick to install verses moving the boxes. With the wallboard off, you might also want to look into maybe adding a seems I never have enough! Should be easy with the board off.

01-23-2017, 12:18 PM
I apologize in advance if I've posted to the wrong forum.

I am preparing to install the pictured honed limestone mosaic tile as a kitchen backsplash. I plan to use a dark grout and was instructed by the salesman to seal the honed limestone before I apply the grout. My question which sealer would be best to use in this situation to avoid darkening the stone. I want to keep the material looking as natural as possible.

I want to be smart about this and do it right so I'd appreciate recommendations for sealing products. This is what I picked up at the dealer Superior Premium Gold water based sealer, any thoughts? Is there something better? When sealing, is one coat enough? Should I anticipate any other issues?


01-23-2017, 03:32 PM
Welcome, Andryea. :)

Please keep all your project questions on this thread so folks can see what you're working on and what's been previously asked and answered. We can give it a more generic title any time you'd like to suggest one.

I think the only way you're gonna know if you can use a dark grout with that tile is to make a test board, seal it and grout it. Or grout part of it unsealed and part of it sealed to gauge the difference.

I am skeptical of products coming from The Tile Shop, but I've never used that particular sealer.

My opinion; worth price charged.

01-23-2017, 10:59 PM
Thanks CX,
I got a little confused when the post got attached to my previous post about the condition of the walls that I am tiling. I tried to delete it and repost it in the right place but obviously that wasn't the right thing either.

Thanks for your advice to do a small sample first. Duh, good idea! I also decided not to use the sealer I got from the tile shop. Instead i will use 511 porous plus sealer.

Thanks again.

02-03-2017, 11:22 AM
I am installing a limestone backsplash and while I'm intending to seal with 511 Porous Plus Sealer and grout with a color darker than the tile I'm concerned with the grout not cleaning up entirely.

I did a sample where I sealed one side (bottom right) and didn't on the other (top right) and then grouted with Sable Brown to see how badly the tile would stain. Pretty bad. The side that was sealed not so much BUT is still darker than the tile is before grouting (left).

With all the experience and wisdom on this forum I bet somebody knows the answer to this question. Is there one mfg's grout that will stain less than another mfg (Mapei vs Laticrete vs TEC vs...?)? If not, how does one bring the tile back to its original color after grouting if the sealer doesn't do the job?


02-06-2017, 09:01 PM
We installed the tile today and it looks great. Still have the backsplash but I'm pretty happy with the results. Not looking forward to grouting. I'm planning to go with a medium grey grout. Does anyone have any grout recommendations? Are there some that are 'easier' to clean up than others? Do any stain less than others?

02-06-2017, 09:09 PM
I like ardex FL, silver shimmer is a popular grey color for my customers. It's a cement based grout.
I would say that a single component grout like a mapei flexcolor CQ or similar would stain less.

02-06-2017, 10:32 PM
Thanks Ryan,

I thought all grout is cement based with the exception of epoxy grout. Am I wrong?

Thanks for the recommendations. I like Mapei products and if they stain less I'm sure there's a grey that will be suitable.

02-06-2017, 10:55 PM
Mapei Flexcolor CQ is a premixed single component grout that uses colored quartz aggregate to give it the color rather than the colored pigment in other grout. It can take a bit to get used to so take it slow and follow the directions. Only spread a few feet at a time then clean.