"I am doing a free standing tub with a deck around it "

That sounds contradictory.

Why do you need a control valve? Why not just put your hand into the water as it spills out to test its temperature?

Mark, I did not clarify properly. I meant to say the tub is not adjacent to a wall to install the plumbing valves. It is a "drop in" tub with a tub surround to be built around it, under a window. The faucet will have to be on the tub deck per a plumber. Theresa, I am doing this for ADA reasons for someone that needs assistance with getting the proper temperature.

https://support.deltafaucet.com/s/article/Roman-Tub-Scald-Prevention

DeWayne, thank you. I discussed this valve with Delta this morning As I understood it, this valve is built in and the water temperature cannot easily be changed once set. This project needs the thermoststic valve used in shower walls that evidently cannot be installed on a horizontal plane, just a vertical

one

Can't one end of the tub surround be a short wall, to house the valve? It doesn't need to connect to another wall.

That's an interesting idea and I will play around with it. The tub surround will abut a window sill without any extra room height wise, so it can't be at that end and the other three sides of the deck are open all the way around and several feet from a wall. It is a weird layout

"The tub surround will abut a window sill without any extra room height wise"

Sounds dangerous.

Can you share images or drawings?

Normally, people who need assistance do not do tubs. If they do, they have a Hoyer lift, with the assistant running the water, making sure of the correct temperature, and then operating the lift. Those who are able to manage mostly on their own do not use tubs. They use larger curbless showers, with seating.

I'm pretty sure our tub has a temperature control valve- but it is wall mounted not deck mounted. We used California Faucets for our fixtures - lots of options.

ADA would be no tub. But if the person is still physically able, but lacks touch sensation to judge temperatures, the obvious solution is to find a sturdy thermometer to use under the spout, and in the tub.

"ADA would be no tub."

??

We don’t know the user’s needs, other than that they need assistance adjusting the water temperature. So, perhaps a higher wall somewhere around the tub might be the answer. It wouldn’t have to be at the end, but it would have to be near a corner on the end opposite the window, for easy reach.

But, where will the spout be? I don’t think I’ve seen one with the water spout below, only a showerhead above, although I suppose it could be to the side? I don’t think the spout can be above in this case, as it would splash. My shower control is on the wall adjacent to the showerhead wall, perhaps that might work here? Or the controls can be on the outside surface of the tub deck with the spout on the inside?

Lomo, thank you for explaining so clearly why the valve wouldn’t work. You explained what the Delta and Moen reps could not. I’m going to just use a traditional tub filler.