Need help with shower valve replacement

I'm a fairly capable DIYer, but have never been exposed to much plumbing. I'm remodeling the bathroom and my wife picked out a new trim for the shower. It is a delta set that came with a rough in valve (this is a good thing since it wasn't compatible with the current valve). I thought that when I opened up the wall that I would see something similar to the new one since the house is only about 10 years old. I was surprised to see plastic tubing (I think it is PEX) and no threads on the valve. I was hoping for some suggestions as to what parts/tools I need and what route I should go for making this switch. Thanks

The pictures do not open, so we cannot tell what you are working with.

You did not get the right version of the rough in valve. But you could get a PEX to female IPS adapter, or sweat a piece of 1/2" copper and sweat a pex adapter on it.

You will of course need a crimper for the pex.

The pex connection looks more like the Uphonor expansion fitting than a cinch clamp. Not sure how well that pex works with cinch connections. In either case, you could install the proper adapter into the rough-in and adapt to the pex. An alternative that the pros may not like, but does meet code, would be to use a Sharkbite fitting - this would allow you to just push in the pex. I think U072 from this page would work http://www.cashacme.com/prod_sharkbite_pushfit.php. You will want to keep the copper for the tub spout and shower head, as the use of pex, at least for the tub spout, will cause problems. If the ends in the wall aren't drop-ear el's, then you'll want to rebuild it with those to provide a solid support (to blocking) for them. This way, the tub spout and shower arm will be sturdy and not flop around.

Thanks for the ideas... I plan to keep the copper, but wasn't sure how to deal with the PEX. What do you all use to protect the fiberglass when sweating the pipes (or is it something that I should worry about)? Also, the copper that goes up to the shower will need to be cut to get the new valve in. Do I just splice to the old piece so that I can get the level correct for the handle? I assume that there is a sleeve that just fits over the outside of both of the pipes. Thanks again.

what is the major hesitation with the sharkbite connectors? They seem like a good idea, and easy for the DIYer.

From a plumber's viewpoint, they are expensive since they typically have the tools to use a simpler fitting and already have either the expansion tool (Uphonor tubing) or a crimping tool (all of the others - I prefer Uphonor and I think that's what you have there now). So, maybe a buck for the fitting verses five for a sharkbite...it adds up quickly. But, you can't buy the tools needed to either crimp or expand to use a conventional fitting for what you'd spend on a couple of sharkbites. Then, the seal is dependent on o-rings - there are teeth that hold the pipe in the fitting for the o-ring to seal. If you don't use the tool to deburr the edges (about $10), you could slice the o-ring and the fitting will leak (a little twirl around the end with some sandpaper should take the burr and sharp edge off - this puts a microbevel on it that protects the o-ring during installation - the tool does it quicker with a small metal cutter). While not an issue here, since the fitting is sealed with an o-ring and teeth in the soft plastic, the fitting can rotate a little (you can rotate it on a barbed crimp or expansion fitting, too). If the pipe moves, a crimp or expansion fitting may be better, but it's a good idea to anchor the pipe regardless of the method of installation. Bottom line, is first cost, then the 'fraility' of the o-ring. Now, the things are code complient, and work...but, there's more room for error. If you make sure you have the tubing anchored and you don't mess the o-ring up during insertion, it should last forever.