Is that sheetrock? Unless you're going to put Kerdi over it, it should be cement board.

Do you have any pictures of the trim pieces?

Geoffrey, I am indeed going to use Kerdi, as I have on a previous bathroom remodel with good results. However, I can't do anything until I determine how to get the plumbing part. Do you know the brand of this rough-in, or any other identifying information?

zmith, I'm trying to determine the brand of the rough-in. I don't know what trim pieces you have in mind, but they are fairly typical. They won't help us identify the rough-in. Thanks.

When I was trying to identify some plumbing parts I took a bunch of pictures to a local plumbing store and had them look at it (not a big box store, a real plumbing supply place). They were able to figure it out. I had a little more to work with because something had numbers on it that they were able to identify.

Hope this helps- Lisa

I would second Sophie. Get a new valve with thermostatic control.

Sophie, are you referring to the rough-in? The reason I'm not replacing the rough-in is because there's nothing wrong with it. It would be far more expensive to replace the rough-in than to replace a cartridge. Cartridge replacement is fast, easy and cheap once you know what to buy. I don't know what either of you mean by "valve", but the closest thing to a valve, would, I suppose, be the three cartridges.

Please let me know if you have an answer to the original question I posted. Thanks.

AFAIK in almost every country in the US, requires thermostatic valves in new construction and remodels. Looks like a 40 year old valve body. I'd replace it.

Sample Thermostatic Valves

I agree that if it is not a thermostatic valve-it should be replaced for safety sake alone.

I replaced my 1990 bathrooms a few years back and I love not having to worry about being scalded when someone flushes a toilet anymore.

Plus, as already stated, they are required now by code.

Whatever brand your trim was will tell you the rough in brand to help you narrow it down if you decide to not replace it. I didn't realize this and bought delta trim for a moen valve (a year went by between rough in and finishing). I had no idea that valves weren't universal and now I have an extra trim kit in my garage after buying the proper brand for the rough in.

I used this shower for about 6 years, prior to this remodel, and never had a problem. The temperature doesn't change significantly when there is a toilet flush. It's a barely noticeable temperature change.

Id replace with a pressure balanced valve.......and regardless get that drywall away form the shower Even though the knuckleheads at orange say its OK and a few of the other Tile mechanics here on Houzz .....:):) promote it..

You are about to spend a lot of $ and leave an old valve in there. One slight plumbing leak from BEHIND the drywall will cost you an arm and a leg to Redux it again. I have replaced multiple orange showers from drywall that was exposed to water from the wall cavity. Only then do people "get it" and they are never happy about it. "The orange MFG say its ok to use drywall" but they arent going to pay for replacement, they do however love to sell product 2, 3 times until it does work........

If you are persistant to move fwd. Take that Valve picture over to Terry and you will get an answer quickly, hes got a guy named HJ older than dirt that knows every valve from say the 20's !

Grhoe Rough-in - other makes have similar. Valve bolts into rough-in

I agree with Tundra - use cement board. Kerdi and drywall.... I've never depended on a condom either.

Either do the job right, or don't touch it at all. Replace every single thing that you see behind that wall. And the wall. Drywall is just nuts. Because you have a guaranteed leaking situation here at some point. Really really soon if you don't replace the valve.

This kinda half informed halfassed work is what gives DIY renovations a bad name and an eventual really cheap resale value.

And cement board with taped seams and Hydroban is less work than Kerdi.

Does anyone want to answer the question I asked? You're not obliged to, but it's counterproductive to answer questions other than the one I asked. It fills up the thread with information that doesn't address the question, and ultimately makes it less likely that I will get an answer to the question I posed. In general, I think it's good etiquette to answer the question that's been posed, or move on. If anyone has any information that will assist me in locating a cartridge replacement, as per my original post, please let me know! Otherwise, and regardless, have a good day!

Looks like you have PVC, the rough in/drain rough is the part your drain cover sits on. You'd be good to go with all major brands, we actually have a 40% off right now on our full shower drain kits, like this kohler below.