I appreciate all the information. By way of conclusion, we've hired a plumber with whom we've worked before who will replace the valve (I am afraid of copper!) and is also giving us a bid on rebuilding our very badly cobbled together drains. I like working with this guy because he's very experienced, very straightforward, and he will let me help him with some of the grunt work. I write the checks but he's the boss, and if he says something should be thus and so I say "yessir". Works real well! Thanks again. ps- we're putting in a much better valve than the one we're removing.

They now make the both the conventional style angle stops and 1/4 turn angle stops which have exactly the same appearance but they are a ball valve that will turn the water off by just turning the handle 1/4 turn. Typically there is a slight increase in cost for the 1/4 turn valves but the difference is so minor as to generally go unnoticed.

I would also get a plumber engaged. I'm not sure you want have a sprinkler guy do this kind of work since there is a risk of contaminating the public water system if the valve is installed wrong. The threaded fittings on the valves would only be useful if you unsoldered one end and then unthreaded each joint in sequence. However, if they were unions you could take each one apart and just take the valve out without any soldering. Bruce

Bob, compression fittings are allowed for installing shower valves. Moen even has a video showing exactly how to do it. Shark bites are allowed too. .....In the U.S. The fact that something is or isn't allowed in the colonies doesn't really concern Mr. Nobel. If you aren't versed in what's acceptable in his locale , you should say so and take a pass at dispensing advice especially if you fundamentally disagree with the local custom. You may not like people who drive in the left , but have to accept it in places answering to the Crown. geoffrey, im sure you mean well - but a vapor barrier doesn't really enter into the equation since Matt has made no mention of a steam generator. Waterproofing on the other hand is part if the conversation - but that's different than vapor management. Now, value , and what you might do in your own home certainly have a place in this conversation (* sort of) but don't force YOUR bias onto someone else under the guise of "it's not to code" or "it's only for hacks" or "it's too expensive, or you can do it cheaper". * what you'd do in the States really doesn't matter a hill of beans in London . So, maybe some of you guys oughta pipe down a bit. It's OK if you don't want to help or are ignorant when it comes to UK plumbing. Hell, y'all don't even have an accurate handle on what's allowed in your own back yard. Please don't confuse allowed with your preference or good value or wise . You're allowed to smoke. You may not like it, it's cheaper if you don't on many levels , and most will agree with you if you feel it unwise. But, it's allowed and some will choose to do so and think it fine. And who are you to say their choice is wrong ?