Tricks of the trade for vanity replacement?

[atgcpaul]

I need to replace our old double sink vanity with one I made.  My wife wants a back on the vanity so you don't see the wall, and I'd like some kind of back to help keep it rigid, and who knows what the wall looks like back there.

Anyway, the existing vanity was obviously installed before the final plumbing tidbits like the hot/cold shutoffs and P-trap to drain pipe connections were made--there's 2 separate supplies and 2 separate drain pipes.

So what is recommended here?  House is plumbed with CPVC so it would be easy to remove the existing supplies and probably replace with Sharkbites, and I could cut back the PVC drain pipe, and glue on a new one after the new vanity is slid in.  However, that's seems like a waste and a lot of work.  Maybe the happy medium is to cut out a square section of the back so most of the wall is covered?  I still get the rigidity I want and most of the back wall is covered.  And who goes looking in an enclosed sink cabinet anyway, right?

[CLETUS]

   Maybe the happy medium is to cut out a square section of the back so most of the wall is covered?  I still get the rigidity I want and most of the back wall is covered.  

That is a hack job. 

Your house, do it anyway you want... However, I think you should unhook the plumbing and install it correctly.

[fredhargis]

I don't consider the square cutout a hack job, personally. What I did (bath vanity) was measure the rough size needed for the drain and supplies, then cut that out cleanly using a router and template so it looked nice and clean. I'd do it that way again if I need to. My opening was rectangular, and probably 8" tall and 10-12" wide.

[crokett™]

I'd do the square cut-out, but then I hate plumbing and I know that even if I kept all the parts I took off, something would mutate and they'd be the wrong parts when I went to put them back on. No one ever looks under their vanity, and if you look in any vanity in my house there's too much crap there to see the plumbing, let alone the wall behind it. I'd just cut out the smallest size possible, and make it a neat square, and not some random cut out.

[Snipe Hunter]

CPVC... is about the easiest and cheapest product to work with. Not a huge fan but it's what a lot of builders are using. Why bother with shark bites? Just use CPVC. I like neat construction. Cut the holes with a hole saw and slide the new vanity in. Slide flanges over the pipe to hide the hole and put on the new valves. It takes no more time than cutting corners and looks nice. It just takes a tape measure and a 2" (assuming this is a (1-1/2" drain pipe) and 1" hole saw

[Trusty Rusty]

Get it down to the base lines
Put red lipstick on them
Slide in place for a perfect center
Drill thru from the back till the hole saw just marks the back
Go to the front & drill thru
Perfect fit every time
Rusty

[daddo]

Get it down to the base lines
Put red lipstick on them
Slide in place for a perfect center
Drill thru from the back till the hole saw just marks the back
Go to the front & drill thru
Perfect fit every time
Rusty

 Believe me- your wife is going to know you used her lipstick. Be sure and get a written waiver of responsibility of damages signed and notarized.

[Snipe Hunter]

I use lipstick for this very purpose too. Also for marking wall boxes when hanging sheetrock. I've yet to find anything better.

[museumguy]

As some of you may remember, I do this for a living. We hate to cut a square/rectangle in the back. Most of our jobs are remodels, houses 20 to 30 years old. Sometimes we have a difficult time getting the water to shut off properly. The shutoff valves are shot. We recommend that a plumber come out (for company liability issues only) and remove the existing shutoff valves and cap the lines. Sometimes, the plumber will use sharkbites, sometimes he will sweat copper caps on the lines. Keep in mind, it can be a week to 10 days before the counter tops arrive which is why the lines are capped off. If we happen to have the tops and the plumbing is scheduled for an immediate re-hookup, the lines are left uncapped and we proceed. As for the drain lines, we try to cut the drain line as close to the wall but with enough original pipe left to glue a connector back on. We drill a 1" hole for the water lines and a 2 1/2" hole for the drain. All are covered with trim rings later.

Take your time, measure carefully and you'll be fine.

[atgcpaul]

As for the drain lines, we try to cut the drain line as close to the wall but with enough original pipe left to glue a connector back on.

So what about the next guy?  Are they SOL?