Plumbing – Help me remove kitchen sink cabinet plumbing

kitchen-sinkplumbing

I am removing a sink cabinet temporarily to demolish the tile floor under it. The cabinet is going away in about a month when new kitchen cabinets arrive, so after demolishing the floor, I need to put it back temporarily to have a functioning kitchen sink.

The hot and cold water pipes are 1/2" copper with sweated Ts for the taps for dishwasher and icemaker. The hole at the bottom of the cabinet is hard to get to due to cover but looks 1.5" in diameter. The drain pipe is cemented as shown.

What is the typical procedure for removing these fixtures to swap out the cabinets? I don't mind hacking up the back of this cabinet just so that I can easily remove and put back the existing sink but when the new cabinets arrive, I'm thinking I could heating up the reducing coupling (circled in red), cutting it across (shown in green) and peeling it from the drain pipe. Then I could remove the compression fittings on the copper Ts, Pull cabinet forward a bit to clear the drain, and lift the cabinet up, hoping the Ts will clear 1.5" hole. This would avoid me doing unsweating of those T's. Anyone has better suggestions? I have done some limited sweating (actually I added a pressure regulator to my water main and other minor jobs), so I have some experience. Should I just do that? Or since I need to put it back temporarily, should I just cut at the tees and go with Sharkbite fittings that I can remove and pit back at will?

Thanks, David
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Best Answer

Shut the water off to the house, drain the water from the copper lines, cut them below the Ts leaving enough for a sharkbite to grab back on, put sharkbite couplings on. For the pvc drain line I'd flush cut that to the fitting with the green line and get a furnco with a worm drive to attach them back together.

You can then remove the sink and all supply lines and drain lines when you need to remove the cabinet. You should get the sharkbite disconnect tool.

Un-sweating copper under a sink cabinet isn't a job I'd sign up for - cutting seems easier. After you have your new sink and new cabinet you'll probably want to go with new shutoffs and supplies anyway so I wouldn't be looking to keep that portion of copper. I'd convert to pex and go with 1/4 turn ball valve shutoffs - the shutoffs in your picture I find stop working, leak when turning and are harder to use. You might as well just replace this portion of plumbing the last thing you want after you get a new sink / cabinet is for old plumbing to leak and ruin it.

Shark bite fittings have an integral o ring which probably has a shorter lifespan than a sweat fitting - I only use them in exposed plumbing applications. A lot of plumbers actually use them all the time even in concealed plumbing because they are a 100 times easier than soldering.

Furncos are used in commerical plumbing all the time - this is how you join cast iron (quiet pipes, etc). They are made of some kind of flexible rubber like material again the rubber isn't likely to have the same lifespan as the cast but in exposed plumbing and under the sink I wouldn't be afraid to leave it.

When you do your final install you could leave out the furncos and sharkbites if it makes you feel better. They are more expensive than standard fittings and maybe you have another job waiting to use them.