Mitering glazed tile will indeed give you a sharp corner because if you do anything to ease the sharpness of the corner you can waste away the colored glazing and exposed the tile body color within.

When mitering an unglazed through-body ceramic, or a natural stone, you have a bit of leeway there. You can ease the corner a bit while keeping the tile color intact.

Mitering a corner can be tricky too. Personally, if I'm mitering a corner, I prefer it to look like a solid block of material wrapping a corner, which means I want to minimize the vertical stripe of contrasting colored grout running down the middle of that miter. The 45 degree edge of the tile needs support, so you something in there. Sometimes I'll color the grout in the miter post-installation so it better blends with the tile. That's usually more of a stone thing than a ceramic tile thing, though.

Now who's right? Your designer or your installer? I can shift into my "everyone's lazy" mode and offer the scenario you that your designer doesn't want to order you the scant 10' of bullnose you need, because the minimum order he has to make is 50', and if he has to order 50' and you only use 10', what he going to do with the remainder? charge you for the entire box and price himself out of an order? Take a hit himself and hope that he sells the remainder to someone else someday?

Or I can say that your tiler is tired, worn out, and just wants to install easy-to-do bullnose instead of having to miter all those edges and flirt with carrying a mitered corner around a wall corner. Who knows?

Some designers are great with colors, textures and patterns, but might be lacking in the technical knowledge of how some materials or installation methods work over others.

Some installers "have been doing it this way for 30 years dammit, and that's the way yours is going to get done too." He always uses bullnose on corners like yours and why should yours be any different.

I guess you'll just have to answer these questions:

1) If the edge remains sharp, is it in a location where it could cause injury? Think adults brushing past it, little kids smacking their heads. Think someone snagging piece of clothing. If so, then the edge should be eased.

2) If the edge should be eased, can it? ie, is this a glazed or unglazed material.

If the edge can be eased, then you have the option of doing that. If it can't be eased, then you need bullnose or a different material/idea altogether.

Overall I don't try to push installers to do things with materials that they are not comfortable doing. It's the best way to come up with a failed installation. But sometimes designers need to be pushed to come up with materials that can actually perform in the design that they drew up.

Lacking brevity,
Mongo

I'd go with the bullnose. Mitering is only for when bullnose isn't available, IMO. It CAN be done so that there isn't a sharp edge. In fact, if done properly, it WON'T have a sharp edge. But it's still a very fragile corner treatment-- very easy to chip. This is why it's a last resort, for me, anyway.

Mongo, I appreciate your lack of brevity! :)

This is a glazed porcelain tile, so I don't think the edge can be eased or softened in any way. It's too late to change to another material for the room -- and we don't really want to, either. I suppose we could look for an entirely different material for the niche, but that would still leave us a sharp wall edge where I do think people could bump it and hurt themselves. Here's a sketch of the room, with the corner I'm questioning in the red square:

The installer is not a full-time "tile guy" by trade; he's a GC who does very good, detail-oriented work. He did our kitchen with great results, and we've seen photos of several recent bathroom tile projects he's done. He said he certainly could miter the tiles (e.g. knows how to do it, has done it on jobs) and would do it if that's what we want; he just raised the concern about having a sharp edge -- which I appreciate because I hadn't thought of that.

The tile shop owner isn't being lazy about ordering; in fact, he's a direct importer and wholesaler of some tiles, including the one we're using here. He checked, and he's got about 70 bullnose tiles in his warehouse -- so quantity or odd lots aren't the issue. I think he just suggested mitering because in his mind it gives a cleaner look. I'll go back and talk to him about the sharp corner concern to see if he has any suggestions for this tile which would reduce the sharpness; otherwise, I'd be inclined to use bullnose tiles for the one wall junction and the tub niche.

-- Eric

Thanks for your input as well, Bill. (I was typing my first reply to Mongo when you posted, so I didn't see your reply until later.) You've both helped convince me to go the bullnose route. I don't want sharp, I don't want fragile. And the bullnose approach seems less likely to have complications.

You guys are great! Thanks.

-- Eric

This is a follow-up question to Mongo regarding the grout line on mitered corners.

I'm in the process of tiling two 12" x 12" niches in a tub surround. The tile is 7" x 7" Crossville porcelain with micro-beveled edges (approx. 1/32") and the grout lines are 1/8". For the outside corners, I've mitered the back of the tiles up to the edge of the micro-bevel.

My questions are:
In your previous post, you say you prefer that the grout lines on outside mitered corners be as small as possible. Can the edges of the two tiles forming the corner be set against each other so that there is no grout line? If I set them at 1/16", will I be able to use sanded grout - as I plan to do for the rest of the tile - or, should this be caulked?

Also, any recommendations on setting the tile in outside mitered corners would be appreciated. I plan to insert tile spacers in the grout line and use tape to hold everything in place.

Thanks!

If bullnose tiles aren't available, and you don't want the mitred corners, you can always go the Schluter bullnose profile route. I believe Bill has some pics of them in use somewhere. They're not my style, but you may like them.

Dan

i agree with Schluter or other profile strips.
One day I may get around to posting photos of those 8' lengths, cut to make corners; it saves you the money of buying the small corner piece, and it looks clean. I have bought a lot of that same one shown above, the AK color and finish.

Also, one more tip:
with attention and time, one can miter the backs of tiles so as to remove only about 80% and not all, which when doubled to make a corner with another tile cut the same manner, looks good and does not leaves a sharp corner. --- And your Grout makes the corner rounder and rounder too.

One day I may get around to posting photos of that.
(i didn't read everything above slowly, so i may have missed it if this was already mentioned.)

hth
-d

Our tile guy is pushing for mitered corner instead of bullnose. He assured me it wouldn't be sharp and I would like the look much better in the end.

He will be doing what davidro1 said.. cutting off the back of both tiles. I will post a pic when he's finished.

Eric is the wall behind the door opposite your vanity getting tiled as well?

I have a little trick for pulling off a clean look in set ups like yours.

The key is exact framing and we run the drywall (behind the door in your bathroom for example) past the edge of the corner stud and far enough so that when a J Bead drywall trim is installed it is far enough off the back wall of the tub that cement board and tile thickness is 1/8" less than the finished drywall bead. This jbead will cover the edge of the tub as well and leave just a 1/2" or 5/8" profile.

This way the back wall gets tiled and you don't look at the row of cut tiles or factory edges when looking at this detail.

I can post a picture if you want more details. Your drawing is it to scale?

ntruro,

Bill answered the question. You need something between the mitered edges, they can't float next to one another.

In the photo below, these are faux-slate solid body ceramic tiles, so I eased the edge just a bit with a carborundum stone. They're gapped a bit and grout was worked into the joint, so it's a very slightly eased corner. Still a strong 90, but not sharp.

I then colored the grout within the miter to match the color of the tile. The seam is truly invisible, it looks like a solid block of...faux slate ceramic. lol.

Be a solid block,
Mongo

John, we're planning to tile all the walls to the ceiling. Yes the drawing is to scale. (The bathroom is 8' long, the tub area is 60"x32", if that helps.) And if you could post a picture of what you're describing, it would be a great help, because I'm not quite understanding. Thanks!

-- Eric

While I was thinking about how this would look with a bullnose tile, I realized I hadn't tried to visualize how the tile would lay out on the tub alcove wall. Here's my guess at how it could be done:

If we used a bullnose on the left edge, where this wall meets the wall behind the door (see diagram several posts up in this thread), and on the right side cut tile to the same 3" wide size, that comes to about 32.5 inches (with grout) for this approximately 32" wall. That seems to me like it would work well. I know the "13x13" tiles may not be precisely 13" -- I have to go check their exact size -- but is this the right idea? Or would you lay it out differently?

If we do it as shown, that means dead center of this wall is a grout line, and dead center is where I would think I would also center the items on this wall: (from bottom to top) tub spout, pressure balance valve trim, grab bar with adjustable showerhead. Is there any negative to having these items centered on/cut into the line between two tiles?

Thanks, as always, for the advice and guidance!

-- Eric