BEFORE I buy new tub/shower trim - some questions

[Trabaja]

[I think I posted this to the wrong forum before... if so, I'm sorry for the duplicate post]

BEFORE I buy new tub/shower trim - some questions

Questions about upgrading tub/shower trim - will this new trim work?

I want to upgrade our Avante Price Pfister series 09 tub/shower trim and have committed to finding out if it's reasonable. Given the location of our valve our plumber strongly advised we upgrade the valve rather than replace it and we agree. This means we will install a retrofit kit so the old valve can be used with newer trim and Price Pfister told me which trims will work with the retrofitted valve. Now my question:

The picture below is the hole in the wall for the old trim with the valve behind it. The hole is 6 1/4" wide and 3 3/4" high. The surface in the picture is cultured marble. I should mention that there is no back access. The PP model that I think may work is the Avalon R89-8CBC.


The specs say the trim flange is 6.88" diameter (it's round). But there is no information about the size of the gasket flange (see picture below) so I don't know if I have enough leeway there for the gasket flange. Is there a standard thickness for the gasket flange? I need to make sure it is on the surface and not in the hole.


The instructions for the Avalon series indicate a hole of 4 3/4” Dia. or 4” Dia. for Thin
Wall Installation (Picture below).
1. I assume this means we have to make the height of the opening larger. Is this so? And does anyone know if cutting cultured marble is difficult and/or expensive?
2. What is Thin Wall Installation? Can you tell if that applies here?


If we proceed with this, we'll have a plumber do the work. What I need to know is if it is possible (that is the new trim would fit) and if it is reasonable (that is to cut the marble, if necessary). If it is, then I'll figure out about enlarging the opening, buy the trim, and call the plumber

I want to thank you in advance for any help you may have to offer.

[jadnashua]

I have to disagree with the plumber...I think you should replace the valve. While you may have to cut the stud some, it should be doable from within the existing hole. Worse comes to worse, you could use a remodeling plate if the hole needs to be enlarged some. A remodeling plate is a larger plate to cover the bigger hole (yes, it's fairly easy to cut that material), that the new plate then fits on. I don't think that the existing valve has the required anti-scald technology in it, and I don't think it can be retrofitted without changing the valve body. While technically, just replacing the trim might not require upgrading, for your safety, and resale value down the road, it's a good idea now.

Note, unless the new cover plate extends beyond where the old one did, you'll see the discoloration where the old one stopped and be reminded of the remodeling every time you look in the shower. I don't think you can polish that out.

Think wall is something like fiberglass that is literally, thin. Your surround is not that type.