Plumbing in Kitchen Sink Base Cabinet

[stuman1974]

I should be receiving my kitchen cabinet order in a few days. Trying to leave the kitchen somewhat functional as long as possible, I have not yet removed the dishwasher, sink, and sink base cabinet. I believe these cabinets are original with the house which is 29-30 years old.

Unfortunately, the hot and cold copper pipes are not in the back wall like the PVC, but come through the floor of the cabinet. Removal of the existing cabinet I'm not too concerned with (I can cut and hack the floor to get around the pipes). But I am concerned about the installation of the new sink base cabinet. Assuming the PVC Y is fused to the back, I'm going to need to be real creative in cutting and placing the new base cabinet.

I'm not clear why the vertical copper pipe is so tall past the two valves...maybe a water hammer suppressor? If so, they definitely do not work since I get a bang every time I turn off the sink faucet. Do I disconnect and remove the dishwasher valve (at bottom of left hot pipe) and then cut the cold right pipe near the bottom as well while leaving a couple inches to attach a new valve?

I know I'll need to at least cut a couple of holes in the bottom and likely a slot in the back of the new cabinet. But due to the darn vertical pipes, I can't just slide it in towards the wall along the kitchen floor. Maybe somehow cut slots in the floor of the new cabinet to clear the 2 water pipes and then tip and slide the cabinet? I'm just trying to prepare and any ideas you have would be very helpful. Thanks!

 

[Terry]

Old school air chambers for the water supplies which can be eliminated. Now we use a hammer arrestor for the hot (dishwasher) and the cold if there is an icemaker.
You can cut the pipes lower and add on after the cabinet is in place. You will want new shutoffs at this time. The old stuff won't last forever, and the rubber on the multi-turn shutoffs can break up on the hot side and float up into the faucet cartridge.

 

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[stuman1974]

Thank you for the reply. I have a couple of AA hammer arrestors on the back of my clothes washing machine and they worked great in eliminating the constant banging. Great devices and I'll likely add them under the sink as well if the banging persists after the new cabinet is installed.

Does it matter how high or low the valves are on the hot/cold pipes? If I cut low, I could keep the dishwasher valve near the bottom or replace it with a 3-way (to supply the sink faucet and the dishwasher). The cold I'd suppose could be a few inches or so from the cabinet floor as well. Just as long as all are accessible. Eliminating those tall air chambers will be nice too.

 

[Terry]

Many new kitchen sinks come with their own supplies. You may want to have the shutoffs for the faucet high enough for that in the future.

 

[Dj2]

When you have the old cabinet out, why not re-route the hot/cold supplies into the wall and up a little closer to the sink?

 

[Ladiesman217]

I know I'll need to at least cut a couple of holes in the bottom and likely a slot in the back of the new cabinet. But due to the darn vertical pipes, I can't just slide it in towards the wall along the kitchen floor. Maybe somehow cut slots in the floor of the new cabinet to clear the 2 water pipes and then tip and slide the cabinet? I'm just trying to prepare and any ideas you have would be very helpful. Thanks!

That is the way my pipes run.

In my house I had access to the hot and cold pipes from the basement. I cut the pipes off down below in the basement and temporarily capped them in order to get the base cabinet in. Then I installed new pipe extensions after the cabinet was in place.

Can you work from the level below the kitchen?

The right pipe has a coupling down fairly low, so you could cut the pipes in the cabinet at that level.

The left pipe shutoff is low, but looks to be a threaded valve. Remove the valve and cutoff the pipe at a convenient level above the valve fitting.

Drop the cabinet in over the short pipes, then do a minor pipe job in the new base cabinet.

 

[Ladiesman217]

When you have the old cabinet out, why not re-route the hot/cold supplies into the wall and up a little closer to the sink?

It gets cold in Illinois. No water pipes in outside walls.

 

[stuman1974]

Thanks for the comments. Very helpful. Yes, being in IL, I think it's best to not put the pipes in the exterior wall. Likely will leave in the position they are in, even though inconvenient for the cabinet install.

Here's my current thoughts for the steps I'll take.

1. Remove current base cabinet. Not going to repurpose it, so I'll be cutting it wherever needed to allow for removal. Sink and PVC fittings removed and disconnected first of course. Probably cut and cap the vertical copper pipes at about 2-3 inches above the cabinet floor.
2. Clean up whatever mess is below the cabinet. Probably hasn't been exposed in 30 years.
3. While leaving about 2-3 inches of copper pipe above cabinet floor level (will verify against new cabinet if same height), cut out a large enough hole in the cabinet back panel to accommodate the electric cable, bonded PVC wye and the rough out below. Also cut holes for the copper pipes that are large enough (or oval) towards the wall.
4. To install the cabinet, slide in close to the copper pipe, rock the cabinet forward (lift wall side with door side against floor) and carefully lower over the vertical copper pipes through the holes. Then slide the small remainder of the way to the wall.

Will be a bit tedious, but think that could work? I'll have to check it probably 10 times and hopefully not cut any cabinet holes larger if I can help it. But definitely open to better ideas!

 

[Jadziedzic]

Assuming you have a basement, why not just cut the copper lines there, place your cabinet, drill holes in the cabinet bottom from the basement (using and long drill bit through the existing holes in the subfloor), and then run new copper from the basement up into the cabinet? MUCH easier than trying to slide/rotate/rock the cabinet into place.

 

[stuman1974]

Hi, to be honest, I've never welded copper before and was planning on using compression ring fittings and shut offs in the cabinet under the sink.