You can use a Finpan to recess the shower area some into the joists, and raise the rest of the room some. But you will be doing a full wetroom, no matter what.

IMO wet rooms are just plain silly and a curbless shower is a must if you need access for a wheelchair or walker but if you are able boddied do a curb and a nice shower screen and put the tub in the bathroom not in anyway in the same space as the shower .In that size bathroom you should be able to fit a tub but maybe not free standing.

Do the curb. Aesthetic over function never pays off.

You can't do it without lowering the floor of the shower.

The aesthetic advantage in so many of these online images , does turn out to be a day to day nightmare.

" Sweeping" shower floor water, out into the vanity area, via a door makes no sense either.

Unless you are in a wheel chair, can't lift a foot, and severely mobility restricted? Need full ADA capability in the bath? A low/shallow curb hardly ruins the look of a well designed bath.

You can cut out the subfloor only in the shower area and use a TI-ProBoard which is a structural panel designed to replace the subfloor and can be used in your situations... just follow the manufacturer's instructions and create a 1/4" per foot slope leading to a linear shower drain and put the door after the the drain and you have your shower without the curb.

True that........but it's not much of a drop: )

This is an existing bathroom -- a remodel? Then it's almost impossible to change to a curbless shower. You'll spend money, money, money and likely end up with a leaky mess.

What is your reason for wanting to go curbless?

Consider you can go with a minimal curb -- 2" -- and that's pretty low.

A true accessible bathroom is much more than a curbless shower. Wide doors, blocking for grab bars, a wall hung type vanity, with chair space under it. And located on the ground floor, adjacent to a ground floor bedroom, so stairs are not involved in accessing it. Then there is the matter of getting into the home itself, and that being an accessibility issue. ramps or lifts, and wide doors are the start.

We considered it, but our contractor talked us out of it, even though our entire master bath is waterproofed. He said sooner or later something will happen and you'll be glad you have a curb.

As DeWayne said, our townhouse would not really work for a disabled person, so why sacrifice a leakproof shower for something you don't need.

Have you ever used a curbless shower? I have, in several different hotel rooms. What a nightmare mess. Who wants to squeegee an entire room after a shower? Soap and hair everywhere.

This is a remodel. The toilet is being moved to the opposite end of the shower area, thus leaving 11 feet in length for a double sink vanity and then the shower. We have been in a hotel rooms which were wet rooms, especially popular in Europe and most recently in an ada room in the states. I agree everything getting wet is not to our liking. We are considering a wetroom with tub against the wall, then 5x4 foot shower, enclosed with a curb and shower door. Skipping the curb is just an aesthetic want. Our current curb is a 4" box, the same size our contractor said is needed for CA code, not the 2" size mentioned above. We are doing a traditional wetmop for the shower (possibly adding a tub so this is when it would become a wetroom). We are considering no door if we skip the tub as the shower heads would be 4 feet from the curb and vanity would follow. This photo is the option with built in or freestanding tub. Thank you all for your help!

Get a shower pan - super low - I have a Kohler Ballast. The step height is 1 5/8" tall. It's a better solution (cheaper, less likely to leak, less likely to have someone muck up your floor / joists) and gets to close to the look you want.

Just say no to wet rooms.

https://www.us.kohler.com/webassets/kpna/catalog/pdf/en/K-1935_spec_US-CA_Kohler_en.pdf

https://www.kohler.com/en/products/showers/shop-shower-bases/ballast-48-x-36-shower-base-with-center-drain-1935?skuId=1935-0

Wet rooms with tubs inside them are horrible, and mot will be guaranteed to leak. Hot mop for sure will. Build a giant shower pan, and then cut holes in it for plumbng pipes. It makes zero sense for either a shower or a tub. No one ever uses the tub anyway, so just get rid of it.

" Our plumber says he has seen them and there is a "trick"

This is it. Sister 2x4's 3/4" below top of joists. Fill with 3/4" subfloor. Use a pre-fabricated base for tile. Your qualified installer will do the math determining underlayment's, uncouplers, waterproofing or which combination is needed for the specific project.

I've used this method often.

GN Builders is suggesting the same method above.

My husband put in curbless shower 2 years ago. Love it. No door and no water escaping outside shower. No cutting joists.

After 3/4 inch subfloor was removed from our floor a 1 inch thick FASTDEK base was used. Our remodel was on first floor but a friend of mine used the same base and method on her second floor.

We remodeled our bathroom using the described method above. We went a step further and used a wall hung Koehler toilet and a floating vanity. We love it. Total open floor on one level. Super easy to clean. You CAN have ascetics AND function.

We wanted a curbless shower for our 2nd floor bathroom remodel for the aesthetic appeal. Our contractor refused this for our remodel and stated it could be done on a new build. What we did as a compromise was have a short curb, 1-1/2 inches. We exactly matched the color of the floor tile both in and out of the shower to the shower jamb color and when the bathroom was finished it looked great. One's eye just took in the entire floor as one piece.

Ours wasn't on the 2nd floor but we had two installed in our last house (after having cared for aging parents and realizing that no matter how low the step, if you can't do it, you can't do it.

Anyway, we had two installed and the "trick" is that the tiler has to know how to *gently* create a slant toward the drain so the water is running toward the drain. We never had a problem. I don't understand what the contractor thinks is magic about the curb. ? Anyway, that "trick" does require a stellar tiler who "gets it". We found one and it was all good.

Hope this helps and good luck!

We are just finishing our 2nd floor bathroom remodel without a curb. I didn't want glass to clean and have a large bathroom. Just started showering in there and water does not go all over the place, it flows towards the drain. I can't think of what they called the process and materials used to make this happen tho. Our tiler made it happen like the post above says. I love it. Good luck getting what you want!

" we had two installed and the "trick" is that the tiler has to know how to *gently* create a slant toward the drain so the water is running toward the drain. "

Which is why the earlier answers all state lowering the pan into the floor joist system using one of the methods above. That is really the only way to achieve that "gentle slope".