Plumbing in the Home/Replacing copper 3/4" T in cold water supply line
The home we bought was built in 1963, and is entirely plumbed in copper, (except for some recent drain traps.) After the whole house water shut off, the water line T's off into the hot water heater, but about 12 feet away, the 3/4" water line T's off toward the master bath, running along the bottom of a joist. A few inches further, the line turns left and angles down to another joist where it feeds the guest bathroom, etc.
The T that feeds the master bathroom line is corroding...and produces a drip once an hour. this has discolored the linolium flooring directly underneath the drip, in the basement. This must have occurred for years, as there is a small crater under the drip. (Maybe it melted when someone sweat soldered the joint years ago? Who knows.)
The wife wants this fixed. I'm afraid of bringing a torch to bear, as the wooden joist is immediately above the line. However, I am toying with a "Shark-tooth" push-on replacement. Is this a good idea? The location is VERY accessable, well lit and in the center of the house. (Can't figure out why someone has not solved this before!)
Second, if I do replace this T, breaking the line while the water is turned off, I might consider installing some sort of ball valve shut-off lever. This might allow shutting off either the main bathroom or the guest bathroom water. Can you think of any reason why this would be a good idea? I have no plans on remodeling either.
Corrosion and green crud on a fitting indicate a poorly soldered joint. It was probably not properly cleaned prior to soldering. Shark teeth fitting work great for those who do no wish to solder. As for the shut off valves, unless the fixtures in the mentioned bathrooms do not have shut offs on the supply lines in the cabinet or under the toilet, I would probably not install them BUT keep in mind if there is a tub or shower in the bathrooms, they most likely won't have valves and you will have to shut off the main to replace faucets.
If you decide to solder , replace the fitting It's not worth the trouble to try and reuse.