ok..im pretty handy but b4 i dig into this one, i want to find out the least destructive way to get this done.
my whole valve inside the wall needs replaced, i warped the valve housing awhile back trying to remove the large circular ring that holds the cartridge in, and i know what i did wrong but even putting in new cartridges, it leaks as it ends up tearing the orings, i have tried several times, so....
this is a newer home, has a delta monitor, single pull knob shower valve, and this is in a wall that is in the exterior of the house, main floor, vinyl siding on the outside. the shower is a single piece acrylic or whatever, like what they put in almost any knew home i guess, its a shower/tub, all in one. on the wall where the valve is, there is a small bumpout from the exterior wall, i guess which makes it so they can accomodate room for the valve and insulation and whatever, pretty sure this is a basic and common setup, and by bumpout, i mean if you look at the end of the shower that has the faucets, the sheetrock comes in maybe 10 inches or so just right at where the shower insert starts and therefore making the thickness of the wall cavity between the shower on the faucet side and the outside of the house slightly larger than say anywhere else in the house between the sheetrock and the outside of the house,
when i damaged the faucet in the beginning, i had cut out that little 10 inch bumpout if you will call it, to where you could reach your arm in sideways right at the level of the valve and get to it, kind of around the framed 2x4's in that area. so you can see directly in to the valve exactly because they had to frame for that 10in. bumpout but you can reach your arm behind that framing and touch the valve, although its a reach and somewhat awkward, not great acccess is what im getting at.
the valve is currently installed with pex plastic tubing, and i forget the name of the bands, but they pex is connected to the valve with those plastic rings that you use a tool that stretches them for a few seconds to let you slide them over the spot where the pex is pressed onto the valve and then they shrink back to make a water tight seal.
so, long story short, there is a sheetrock ceiling in the basement under this and that would be quite a distance up to the valve, so that would be hard to get to from there, once you take the valve "handle (hot cold)" off, you have the large circle that is cut in the liner that you have access through and of course the valve is right there, and you have some access, but hard to put any large plumbing tools through there very well, you can but dont have a lot of working room and definitely hard to have a hand/arm and a larger plumbing tool stuck through there at the same time. and the other option for access i guess would be removing the vinyl siding from the outside in that area, and cut a hole in whatever type of paneling is under the vinyl siding, plywood would be my guess.
the problem i see with getting tools into the shower on/off area, is that although the hole in the liner is big enough to see the valve well, the nibs that you hook your water lines onto the valve are on like top bottom left and right and they arent centered in the hole, they are kinda off to the side, which is why its kind of awkward to get plumbing tools to them, you can at an angle with the crimper style, but once i have to cut the lines off the old valve my water line(pex) is all going to be a little shorter now, am of course my concern is that they will still need to be long enough to reach and connect to the new valve, meaning maybe i cant cut these off, and need to find a way to get the bands off to relase them, and to make it more intersting, one of the lines isnt attached to the valve with the plastic rings/bands, but rather has the metal crimp styple band, so 3 plastic ones, and one metal one, lol.
my only idea would be maybe add a short piece of pex to each of the 4 connections on the new valve first, put it in wall, and then use some of the quick connect compression couplers to attach the old pex in the wall, to the new short pieces i just put on the new valve, i know those connectors arent probably the best recommendation to put "in wall" as they simply wouldnt be considered as reliable, but it would aleviate having to cut holes in the wall and could turn this into a very easy fix..if i were to trust the reliability of those connectors, i have used them in my basement for a utility sink which have been in place for like 4 years, not so much as a drip from those ever, but how much of a risk is it really? i know there is always a chance they could act up, but what are the odds?