Extending shower/bath supply lines

[moobiker]

I need to extend the 1/2 " copper supply lines that exist for the shower to accomodate a new bathtub, that will be in addition to the shower. In looking at the current plumbing, it seems to me that the cleanest way to do that would be to remove the old ell's where they go up through the stud wall and replace them with tee's to run the new lines along the floor joists. Are there any issues with heating up the old fittings to remove them, then sweating new fittings in their places? Thanks, Mike

[Mikey]

A) make sure ALL water is out of the lines
B) don't burn the house down

[prashster]

The ends need to be clean and free from any oxidation. It is possible to do it, but you MIGHT find it easier to just cut the pipes b4 the els, emory the bad boys, reflux and solder the tees on.

[Gary Swart]

Removing soldered fittings is not impossible, but it is hardly worth the time and effort. You have to get all of the solder cleaned off the pipe ends or the new fittings will not slip on, and to reuse fittings, it is even more difficult to clean out the solder from the inside. Cutting the old fittings off will of course result in a loss of a few inches of pipe and probably require a few couplers and short pipe pieces to makeup for what was lost, but it will be the quickest and easiest way.
Of course, all water must be removed before doing any soldering.

[moobiker]

See, this is why it's good to ask. I had not even considered the thermodynamics of heating up the water inside the pipe. Whew! Thanks

[Mikey]

I've never had any problems reusing a pipe end, but never even attempted to reuse a fitting. Depends a lot on how accessible the joint is, and how adept your helper is. If the end is right out in the open, one of you can yank the fitting off and the other can wipe the pipe end with a cloth before the residual solder knows what happened, and you've got a nice clean pre-tinned pipe to work with. If the original solder joint was poor, you'll see gaps in the solder film and really ugly pipe exposed. In that case, cut the end off and start anew.