A curb, nor a threshold can be wood. I will also tell you a shower with no curb in a tiny bath/shower is one bad idea. .........you need to have lowered the shower floor in advance. Or..water everywhere

Solid surfaces abound...granite, soapstone quartz etc to top and waterproof a curb. Go to a stone yard, and look in the remnants, with a tile in your hand

Looks fine for a shower. Grout prevents slips, and seems to me a soft almost matte luster...... no issue

I actually have no clue what thye are asking. Threshold for waht ? The shower is burbless so no wood anywhere near it IMO

The tile is approved for wet areas. The floor slopes toward the drain, the floor was designed to be curbless. The area I’m questioning is betwen the tile and the door that leads into the rest of the house.

@Mint tile Minneapolis, we're looking at replacing a tub with a zero threshold shower (likely dropping the floor to sit flush to avoid needing a reducer at the bathroom threshold; my father has vision impairments and mobility is a bit limited). We're also looking at using a shower curtain instead of glass doors; the potential contractor is recommending a linear drain. Would a capillary stop still be used in the same area and the same way? I googled to learn more and found this page: https://www.diytileguy.com/capillary-break/ - does this align with you? I don't know if most contractors know about this so I will make a note to ask about it. Hopefully I can word it in a way that makes sense and hopefully they know how to do it. Thanks!

DIY Tile guy is A very respected professional in our industry id trust his direction./opinions, luckily you landed yourself on one of the very FEW respected tile info sites on the web w Jims page..

Id add it is never a good thing when a homeowner sources info online and tries to get their contractor to understand and implement these details. A true tile professional will already have that in their plan and be able to explain it to you, likely going as far as using this as a selling point in the estimation phase to get the project..

Hire wisley is my best advice and yes id wager a bet that aprox 75% of contractors neither understand nor implement caplilary measures.-Good luck to you.

Thanks @Mint tile Minneapolis. Expert help is hard to find, especially in my locale. Good to know about DIY Tile guy. I can only imagine how much extra something other than "the way we always do it" would cost.

I'm still not keep on tile flooring as it is hard, cold and we can't afford under-floor heating. But with a curbless shower, that is recommended as the best option.

Like others, I am confused by your question.

I have wood floors everywhere except my bathrooms and I have no thresholds between bathrooms and the wood.

I thought thresholds existed because floor levels are different between two rooms. I used to have thresholds before I did a gut remodel because I replaced carpet with wood floors and so there were thresholds because floors were different materials and different heights.

I think not having a threshold is visually nicer just like not having shoe molding is visually nicer. It also has the added advantage of being a bit safer since there is nothing to trip over.

If you need a threshold between bathroom - is the question one of aesthetics or one of function?

I needed a threshold for function because the height of the bathroom and the adjacent room was not the same. And yes it make the bathroom less accessible. But it looks pretty. Live and learn!