I'm wondering what the proper way to install tile edge trim around a shower niche is.

Some people leave space for grout in between the mitered edges and some people don't (see pictures for example of both). It seems to me that leaving space for grout is the correct way so water will not seep through and get behind tile.

But perhaps it does not matter as I see more examples of people not leaving any space for grout in the mitered ends.

Any thoughts would be much appreciated.

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  • As you've seen multiple examples of both, I would think that both will work just fine. If you're doing it yourself, I'd suggest leaving a grout joint as your cuts are likely to not be quite as accurate as a pro's would be (practice makes nearly perfect!) and the grout joint will help hide the fact that your cuts aren't a perfect 45° and maybe one came out a smidge short. If you're hiring it out, I'd suggest going with the way you prefer, then talk to your installer about it to ensure he can/will do it that way.
    – FreeMan
    Jun 22, 2020 at 16:01
  • I agree leaving room for grout lines would be easier but I'm fairly skilled and I'm not worried about the difficulty. I prefer the look of the mitered ends being tight to each other but am worried it will leak water behind tile Jun 22, 2020 at 16:06
  • TBH, your example of "groutless" looks like it's actually aluminum/stainless steel and was probably applied with a silicone adhesive which also sealed the joints. If you're doing it with actual tile (that's a super thin piece to cut/break), you could probably squeeze in a bead of silicone along the miter when installing to ensure no water gets behind it.
    – FreeMan
    Jun 22, 2020 at 16:09
  • Grout does not stop water from passing through it. Some Water WILL get behind it regardless. The niche as well as the rest of the wall needs to have a water proof membrane.
    – Alaska Man
    Jun 22, 2020 at 18:02
  • I did apply red guard to waterproof. I did not know grout wasn’t waterproof however. Good to know, thanks! Jun 22, 2020 at 18:06


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