Would you reuse old copper pipes and fittings?

I will be working on my hot and cold supply copper pipes in the bathroom (3/4" and 1/2") and was wondering if there are any concerns re-using old/exisitng pipes and fitting. Would you reuse or would you install all brand new pipes and fittings? The old pipes seem to by heavier/thicker, and the new ones I am planning to install are going to be Type M copper pipes. What would you recommend?

Thanks,

Type M is the thinnest recommended for interior work...I wouldn't have any trouble using the older stuff unless your area has problems with overly aggressive water, and if that was the case, maybe think about either pex or cpvc instead of copper in the first place. Type M nominal wall thickness is 0.028", while K is 0.049, nearly twice as thick. If you heft a stick of each, it is quite easy to tell the difference.

I would recommend type L and use new piping for all the new work. Existing piping outside the scope of the work can stay.

Cut out what you have to, but there's no reason to arbitrarily cut out everything and replace. Reusing fittings themselves is not worth the effort, but possible in a pinch.

We are not sure what you mean by "reuse". You can keep, or "reuse", any copper piping that does not have to changed or removed. But I would not waste the time trying to take the old stuff apart and use it to install in a new location.

If you are working on a project late at night and you find you a one or two new elbows or tees short of finishing the job, then it is worth the time and effort to clean up a used fitting or two. Otherwise, just use new. I keep a few extra common fittings on hand so if my well planned project wasn't so well planned after all, I can avoid reusing fittings. With copper pipe priced as high as it is now, I will save the straight pieces for possible future use. Pro can't mess with that because it take too much time and the customer will pay for the new pipe anyway.

quote; Pro can't mess with that because it take too much time and the customer will pay for the new pipe anyway.

IF they didn't pay for the new copper, they would pay for the time it took to "reuse" the old stugg.

HJ, I think we are on the same page here.

Moved 90% of my Monoflow heating loop to make room for a finish ceiling in the basement, reused all the Monoflow tees and 80% of the 1" copper. Saved a ton of money, did not take long to clean up the 1" fittings and the pre tin made it easy to sweat.

I will never reuse a fitting unless I'm in a situation like Gary said, or sometimes if I can cut out an elbow and sweat the fitting with stubs into new fittings (if that makes sense... its been a long day). In other words, I won't remove pipe from a fitting and reuse the fitting, but I will sometimes cut pipe with fitting still attached and sweat pipe/fitting assembly into another new fitting.

I'll only do this if I know the pipe to be reasonably new. Around here, most old pipe I run into is like 50 years old, so I don't bother... I try to cut out as much of that as I can while I'm at it and replace it, even if it wasn't in the scope of work. The cost now is worth it compared to a leak and all its costs later.

All that said, if I have to do that much work, I just chop out the copper, sweat on an adapter, and run pex. These days I only bother sweating copper for very small repairs/changes, or for certain specific situations (my radiant floor heating manifolds, for example).

In response to Kevink 1955 comments. You save money because you weren't paying a plumber $100 or more per hour to clean up the old fittings. Sure, we DIY folks can save some money by recycling fittings because we are on our own time, and there's nothing wrong with that. Just realize a plumber can not spend that kind of time. If he did, it would probably end up costing the customer more money than new fittings.

I have a landlord client who is notoriously cheap, but in many of the wrong ways. This guy keeps all the old stuff he takes out, and years later when he finds it during another project, will reinstall it. Can't tell you how much money I've made off of him fixing this crap. The annoying thing is, I get so frustrated with him, I'd rather not even have the job/money... but gotta do the stupid crap to keep getting all the good jobs I get from him.

One job we did, we had all the plumbing done, tub installed, etc, and turned on the shower head to test the diverter. There was an unintended body spray coming out of the old copper riser pipe that he had found in the basement and reused. What a PITA... had to tear it all apart and redo it. Not only did he not save any money on materials, he wasted a ton of time and money on labor to redo it.

Scrap old copper... you get good money for it. Its worth the cost to do the upgrade while you're messing with it. I actually have a couple of neighborhood guys who do manual labor for me from time to time, and when I have some of this old stuff around, I'll pay them with it. Saves me the trip, and they like scrapping. Just today I pulled out an old lead water line... set it aside along with some old cast iron waste lines for the next time I have one of these guys help me carry drywall or something. Works great.

We are renovating one of our two existing bathrooms. While the walls are open, we are also providing plumbing for a new basement bath.

The existing cold water supply starts with 3/4" copper. A 3/4" x 3/4" x 1/2" tee then provides water to the kitchen and laundry in one direction (3/4") and the two baths in the other direction (1/2"). The hot water supply is similar except that the tee reduces to 1/2" in both directions.

Figuring that the 1/2" lines to the existing bathrooms is not adequate to supply three bathrooms, I have upgraded the main lines to 3/4", with 1/2" branches to individual fixtures. I'm now ready to tie the new lines back into the old.