Can I raise bathroom sink drain 4"?

Users who are viewing this thread

Flintluck

New Member
Messages
4
Reaction score
0
Points
1
Location
Georgetown, TX
I have a single vanity we're converting into a double. The full size is only 60" with the two drains being about 30" apart, so shorter than 3 feet. The plumbing is installed on an outside wall - so it's load bearing. I don't think I can run a T behind the wall through the studs for this. So instead, I am planning on using a single P-trap on the left side near the drain while drilling a hole through the back of the vanity to go to the right drain as well as install T shark bites to get water to the right side.

The drain location in the wall is about 4 inches too low for our vanity. What would be the best method to raise it 3-4" inches? Here were some ways I thinking I could do it but wanted your advice.

1. I cut out the drain knuckle behind the wall and install a new piece moving it up 3-4 inches. No cuts made to vanity shelves. Would this be okay?
2. Use two 90 degree elbows to give me the extra height I need for p-trap clearance. One cut to back of vanity shelf for current drain height. (updated below)
3. Least preferable, leave drain at current height and cut a channel through the shelve for the P-trap.

Appreciate the help!
 

Attachments

  • Drain 3.jpg
    Drain 3.jpg
    92.5 KB · Views: 52
  • Drain 2.jpg
    Drain 2.jpg
    95.6 KB · Views: 49
  • Drain 1.jpg
    Drain 1.jpg
    80.5 KB · Views: 52
Last edited:

Flintluck

New Member
Messages
4
Reaction score
0
Points
1
Location
Georgetown, TX
Just finished editing a schematic. I think I could also do a p-trap close to the wall like this if raising the drain behind the wall would be an issue. This could replace option 2 as an alternative as I think that one makes an S-trap.
 

Attachments

  • jWr38.jpg
    jWr38.jpg
    39.4 KB · Views: 53

Tuttles Revenge

In the Trades
Messages
3,138
Reaction score
1,011
Points
113
The best way to go would be to install a double fixture cross and drill through the studs with the smallest appropriate drill bit. Most load bearing walls are 2x6 only for purposes of insulation and are oversized for the load part of their job.

Not sure about your local area, but the space between sinks that share a trap maxes out at 30 inches center to center.
 

Flintluck

New Member
Messages
4
Reaction score
0
Points
1
Location
Georgetown, TX
Ah, okay. Center to center for sinks is 32” actually, and I just checked code is 30”. Seems like drilling through studs is the way to go. I can redo my water lines back there too then.

Does a double fixture cross work okay so off center? The drain is 3-4” from the left sink and would require pipe run ~28” behind the wall to the other sink?

And I need each arm to fall still behind the wall at 1/4” a foot, correct?

Also there might be an additional wall behind the bathroom wall as the studs are 2x4s. Is it safe to drill those?
 

Attachments

  • 30B3AC7C-A9D3-4155-956D-A13448E73FDC.jpeg
    30B3AC7C-A9D3-4155-956D-A13448E73FDC.jpeg
    148.9 KB · Views: 51

Flintluck

New Member
Messages
4
Reaction score
0
Points
1
Location
Georgetown, TX
This might be overkill, but I removed the rest of the drywall, and they are definitely 2x4s. I also obtained a copy of my blueprints from the city, and I've attached the page with the stud layout. You can see I circled in red where I've opened the wall. It doesn't show a double stud there for some reason.

So load bearing or not, can you drill a 2" hole through these for a drainage pipe? I read as long as they’re not bigger than 60% of the wood & at least 5/8” from the edges, I should be okay. I’d be right at 59% with one of the studs, so I think I’m okay. But can I also drill smaller holes (center stud) below or above that for the two water lines?

I was thinking I'd buy this 2in pvc pipe couple for the bottom where I'm raising it. Then I could use the 2 in. x 2 in. x 1-1/2 Double San Tee for the two drains. Would I then just use two 90 degree 1-1/2" pipes for where the drains come out of the wall?

EDIT: Link to higher res blueprint
 

Attachments

  • drwall cutaway.jpeg
    drwall cutaway.jpeg
    72.7 KB · Views: 49
  • Blueprint.png
    Blueprint.png
    157.1 KB · Views: 49
Last edited:
Top
Hey, wait a minute.

This is awkward, but...

It looks like you're using an ad blocker. We get it, but (1) terrylove.com can't live without ads, and (2) ad blockers can cause issues with videos and comments. If you'd like to support the site, please allow ads.

If any particular ad is your REASON for blocking ads, please let us know. We might be able to do something about it. Thanks.
I've Disabled AdBlock    No Thanks