I need some assistance and advice on opening up a wall preparing for a plumber to move a drain and 2 water lines for me. I'm not going to be doing the pipe work, too advanced for my lack of plumbing ability. That said, I am looking to cut the drywall and have the space ready for the plumber to save time and cost.

The current drain is in the wall and roughed in, and I have decided to change the location. It will need to move 5 feet, take a turn, then 7 more feet. Total of 12 feet. The plumber estimated that with the allowed drop per foot this was possible. We plan to put the drain and water lines at around 21 inches high at the location in the second photo below above the central vent on the wall in (following the red arrows).

I'd like to cut enough drywall out with a dewalt multi tool (hoping that works, never done this before) starting above the baseboard and up to a height that will work. There are 2 layers of drywall (double thick for sound insulation) and 2x6 behind.





I do have photos of the wall opened up (during initial construction of home) as well I can share. I just misjudged where I would want my bar sink. Sadly.

I was also told I should ask for a "studor vent" due to the distance of the run, does that make sense to everyone?

I appreciate any advice, love this forum!

 

studor vents, or air admittance valves (AAV), may not be allowed in your area. Your plumber will know for sure.

Just be aware removing more drywall will be just as easy to fix than a small one. It may also look better as it is easier to feather out the seams. An oscillating saw will work but it will go slowly. A reciprocating saw will be faster but may cause more dust. (Run a shop vac while cutting)

Are you putting cabinets (uppers/lowers) on the wall where you will be cutting and will you be putting a tile backsplash? These may help hide where you are cutting.

 

Thanks. Unfortunately the first wall (where the current pipe is located) I will have to patch, the second wall after the turn, most of it will be covered by cabinetry for the bar except the first couple feet. Both areas will need to be patched.

I was expecting to have to patch and repair the drywall, which I will do at the end. My key focus now is to determine how low to start (I am thinking in line with trim) and how high to go, to allow a plumber enough room to work to angle and extend the drain pipe and water lines to the new location. Is 2 feet enough height?

I don't mind going slow as long as I can keep the cut mostly straight and also a way to set depth would be nice to not cut into the studs.

 

Two layers of drywall ?
Is this a firewall between condo units ?
Is there a basement ?
Did you actually have the plumber there ?

It's one thing to move lines several feet but to go 12' and then around a corner.
That means the corner will need to be cut open and if it's load bearing it will be a problem.
The proper way to do it would be to remove the lower trim and make one cut above the existing connection. Remove the sheetrock from your cut to the floor. Only one seam to fix.

You need a 1/4" of pitch per foot of pipe. That would be 3".
So your sink may need be higher than normal.

 

2' will only give you 24" above the finished floor. With your water lines at 20" I would recommend going at least 36". A ven,t I believe, needs to be above the sink level so you might need to go 48" which will likely put you at the drywall seam.

Why don't you call the plumber and ask him what he wants? You're trying to make his life easier right?

 

Thank you guys, really do appreciate your time. I'm going to go up close to 3 feet so there is a lot of room. Never opened up drywall before and I'm dangerous with tools. All the ambition and none of the skill. So yesterday I decided to try and score the wall with a box cutter to help me cut straighter lines with the multi tool which seemed to be jumping all over the place. End result was 5 stitches at the hospital after the box cutter slipped and took off most of the tip of my finger. Good times. So I'm using a pencil today and feeling a lot less confident but would still love to open this wall up before the plumber arrives next week.

For good measure, including the photos I could find from before the drywall went up, of course any additional tips welcome. My goal is still to at least open up the wall (I'm going to try and not have to remove the bullnose corner) and have a space where the plumber can access the 2x6 to run the drain and lines over to the new location. I figure he can cut the drain low at the current location to get the drop he needs.

Looking at the counter height and the depth of the sink drain we believe we need the drain to be under that 21.25 inches.

 

There is nothing simple, neat, and clean when removing drywall, remember the drywall was glued to the studs so it's not likely to come off in one re-usable piece!

 

Can't remember the last time I saw drywall glued to the studs on a wall. Ceiling maybe.

A pencil line is fine for a guide. No need to score the drywall. Depending on what you are using to cut..... you can attach a 1x2 below the cut and allow the saw to follow that as a straight edge guide.

I've used a sabre saw with a blade cut off at the depth of the drywall. The saw follows a guide easily. Makes a 100% straight and clean cut. Minimal dust. Dust can be contained using a shop vac during the cutting.

A vibrating saw cuts with less dust but is hard to guide for a straight line. You could still use the 1x2 method but blade depth must be considered so that the romex doesn't get hit.

 

Sorry to hear about your finger. Ouch!

As mentioned earlier a reciprocating saw works well. The hardest thing is getting started as the blade tends to jump around. You can pre-cut a slot in the drywall with a keyhole saw. When cutting just make sure not to cut too deep and just skim over the studs when going horizontal.

 

Thanks so much everyone. So we figure we can be no higher than the 21 inches off the floor since our countertop will be 36 inches and our bar sink depth to drain, undermount, will get us to the 21.25 inches. We can be lower, not higher.

With the walls opened up the current drain can get cut down so we can get the drop. No reason the current drain needs to be where it is height wise. I am worried the corner will also need cut but will hope for the least damage to need to repair. We opened up the shorter wall more due to need for more electrical lines run.



The blue tape mark is where the water lines and drain need to go.

 

Seriously? I have never built a hose or had one built that glue was not a mandatory requirement. I would hate to think how bad the nail pops would be without!

 

It must be a local thing. Out of all the houses I have pulled drywall out of, I can only recall one having the drywall glued to the studs.

 

Glued or not---the drywall is off.

Reality check:

How do you expect the pipe to be installed? Many short sections inserted between and through studs? Notching studs? Can that be done without compromising the integrity of the wall and still be approved with splice plates, etc.? How is the pipe going to be installed at the corner?

And what is going on above the vent? If it is a wall cavity used as a return plenum, can it be penetrated by pipes and still meet code?

If the space on the other side of the wall is a mechanical room, storage or unfinished the pipes could be run exposed there and only penetrate the wall at the end.

Another option would be to run the pipe on the surface of the wall and cover with a bump out "shelf/counter" and cabinets.



This 6 inch wide shelf/counter covers a main waste line that runs horizontally below. At the lip the bowl sink is recessed into the wall space for additional clearance.

Shelf/counter is on the right.