I’m building a kitchen addition. The wall with the stove (not the sink) will have a big tile backsplash (8" porcelain hex), extending up the wall. I've installed a backsplash before, but it was in a place that already had drywall and paint (so we had to work with that). But here, the stud frame is still open.

Should I just install drywall and an appropriate primer on the wall, then mortar? What primer? I like drywall because this is an exterior wall, and I can air-seal it perfectly with gaskets/sealant. Thanks!

  • 1
    To best answer your question, please give us info on what type of tile you plan on using. The size of the tiles the size of the area being tiled. Is it just under upper cabinets, or all the wat to the ceiling? More info please.
    – RMDman
    Jul 18, 2023 at 18:36
  • What about using Schluter kerdi board for the backsplash backer?
    – Ashley
    Sep 28, 2023 at 1:47

2 Answers 2


The best backer for tile (anywhere) is tile backer (cementboard, DuRock®, HardiBacker® etc.) It's literally made for the job. It costs a bit more than drywall, but in the whole cost of a tile job (materials and labor) it's a very small increment over a less suitable backing such as drywall.

Of course lots of tile is installed over drywall. But it's definitely not the best backing for tile, and it's a small cost savings on an expensive project that puts the expensive parts of the job at more risk than using tile backer.

  • I agree, but in many new high-end homes we never used cement board for this. Rarely is enough water sloshed around on a kitchen counter to warrant it.
    – isherwood
    Jul 18, 2023 at 19:44
  • Water resistance is not the only advantage of tile backer.
    – Ecnerwal
    Jul 18, 2023 at 19:46
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    +1 Based on my experience in home renovations... Tile on drywall is a bad idea. Sure it is cheaper then the right thing and lasts long enough to sell it to the customer. But give it enough time, and the house will settle. Things will shift around, Drywall has a lot more flex then backerboard, which flexes about as much as tile. Redoing everything because someone saved a nickle is a lot more expensive then doing it right the first time.
    – Questor
    Jul 18, 2023 at 20:26
  • I've seen dozens of showers done with drywall + Kerdi membrane. It's not my preference (at all), but I wonder if it'd be so widely done if (normal amounts of) settling were such a concern. I'm not really trying to cheap out here... just trying to understand why drywall is such a problem here.
    – borisj
    Jul 18, 2023 at 23:18
  • It's not usually a problem, but you asked for the best solution. See the problem with such questions? We're forced to assume you're equipped with Warren Buffet-sized pockets.
    – isherwood
    Jul 19, 2023 at 12:58

It depends upon how straight your wall is. If the wall is relatively new, is plumb, and has no major bumps or cracks, you might be able to get away with putting the tile over the drywall. But if it has any ridges or anything that is not true, it will be soooooo much easier if you use backer board - especially if you are going to use edge channel rather than bull-nose tile for the exposed edges. I made this mistake on a house that was built in 1950 because there was an issue with the thickness that tileboard would introduce. It took twice as long to get the tile level and I had to temporarily screw down the edge channel while the adhesive dried because the wall was not as true as I thought it was when I started.

In the end, it came out looking great and hopefully will last as long as it would with tileboard, but it just made it take longer. I filled and sanded all of the holes and used a quality latex primer, but I think they make a special primer for it. The thing about a backsplash is that it does not really see very much water in comparison to a countertop or a bathroom vanity, so water is less likely to get under the tile. This gives you some options, but just be aware there are pitfalls to whatever you decide.

Oh yeah: if you are using tiles larger than a few inches, definitely use backer board. I was able to do it with small marble tiles (largest being 2" x 1") but larger tiles will teeter-totter on any ridges and become really frustrating to match to the adjacent tiles.

  • Thanks for the detailed response, David. I framed this wall myself. Any deficiencies will be corrected with a power planer + shims. It won't see water. These are 8" hex tiles, but there will be no exposed edge, except at the top, ~8-9' above the floor. Frankly, I think it's much easier to get a drywall surface flat than, say, a Kerdi surface... where flatness is far from the walk in the park their videos show (at corners, etc.).
    – borisj
    Jul 18, 2023 at 22:51
  • Larger tiles are installed with a larger trowel notch to accommodate such variation in the wall. I'm not sure I agree with that reasoning.
    – isherwood
    Jul 19, 2023 at 12:59
  • isherwood -- Do you ever use mastic? I've done some tile projects, all wet areas, all have turned out well. So... Question about mastic -- which I've never used -- one thing I like about thinset is that if a tile is out of plane with its neighbor tile, you can build up a little extra thinset behind it to correct (talking ~1/8" here, nothing crazy). I'm guessing mastic is unforgiving in that way... if the wall isn't perfectly flat, what can you do if you need to shim out a tile a little to get it into plane?
    – borisj
    Jul 20, 2023 at 23:18

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