My question is whether or not bullnose tiles should be used in conjunction with a rectangular piece of natural stone? Also, are there any problems with using Taj Mahal Quartzite on top of the shower curb?

Is it correct that if the natural stone (threshold cap) is cut with an eased edge, no bullnose tiles are needed on the sides of the threshold?

If you use a single piece of granite/quartz, I'd think it will be quite a lot easier for installation. Perhaps that is the issue the contractor is concerned with. If tile is your choice, the contractor may be concerned that the manufacturer does not make tile trim pieces or there are time delay considerations. You need to ask the contractor to get an understanding why he is so concerned about not using tile.

That being said, you'd think that an experienced tile installer should be able to install both a tile and a single piece of granite to angle back into the shower. Don't count on it. No matter which type of threshold you choose, before you sign off on the work, please take a LEVEL to the shower threshold & ensure the threshold slightly angles back down into the shower and isn't level.

If water reaches the edge of the tile bullnose, your tile is probably level and thus poorly installed. Water should never pool or gather unless the tile is level. No water should ever reach the edge of the tile or a granite threshold.

I am getting the bullnose tile pieces tomorrow. The solid rectangular piece of quartz (or quartzite) is supposed to go on top of the bullnose pieces (that form the side of the threshold). I will have the contractor explain why he does not think that it will work well. I hate to throw away the bullnose tile pieces. He wants to make the threshold sides from the 24x12 tile pieces (and not use the bullnose tile pieces).

I don't care if the threshold looks rounded or not. I just want it to look finished.

If I understand your contractor wants to put bullnose tile on the top of the curb and in addition add a solid threshold on top of that? If that is what the contractor is planning I would hold off and find out if that will work. My understanding it is one or the other. I am not a professional but have never heard of that. Of course that doesn't make me correct. Hope a pro pops in here.

The contractor does not want to use the bullnose tiles at all on the sides of the threshold. The stone fabricator sold me the bullnose tiles saying that those should be used on the sides of the threshold (which will be 59 1/2'' long -- the length of the tub being converted into a shower). The contractor said that it made no sense to him to use the bullnose tiles on the sides of the threshold because the bullnose tiles were not tall enough for the threshold sides. He would need to put a tile underneath the bullnose tiles. The lesson I learned from this is that it is best to have the contractor review the tile purchase order before purchasing tiles (and not trust the bathroom designer at the store).

Don’t do bullnose under a slab curb. It creates the need for a larger caulk line to fill the now larger gap between tile and stone. That, you don’t need.

Silicone caulk should be placed at all changes of plane. Don’t create larger gaps than needed for it.

Thanks for the responses. This is basically what the contractor was telling me as well (why bullnose for threshold sides is a bad idea).

As long as the tiles have been fire glazed, it is suitable for shower wet areas.

99% of our curbs leading into showers are finished will bullnose pieces. No, it isn't a bad idea.

How tall are your shower curbs? Our contractor said that the height of our curb is taller than the height of our bullnose pieces.

Normally 4" which is taller than most 3x12 bullnose's. The tiler can cut a sliver of tile to fit under the bullnose. Sorry, I do not have a photo to share.

Recently did just this. Just use a quartz threshold with the edges rounded and somewhat polished. Looks great, no grout lines and will last forever. Be sure to have him slightly tilt the piece into the shower. Choose wisely, Grashoppah....

Curbs with grout lines always have some water standing even if everything else drains away. The better designed choice is always a solid piece of something there. Without grout lines. For your niche bottoms and pony wall caps too.

Not if the curb is constructed correctly and waterproofed.