DIY Home Improvement, Remodeling & Repair Forum

DIY Home Improvement, Remodeling & Repair Forum (
-   Plumbing Forum (
-   -   Question about waste plumbing when adding 1/2 story bath (

swindmill 01-20-2014 12:58 PM

Question about waste plumbing when adding 1/2 story bath
1 Attachment(s)
I am currently remodeling my girlfriend's 1st floor bath. There is a wall between the kitchen and bath that houses all of the home's waste and supply lines. We had a plumber come in and cut everything out and replace it with PVC and PEX. While this wall is open, I was thinking it's worth considering running plumbing to the attic, which is huge, in case we want to add a bath up there in the future. My question is what would have to be done for waste pipes on the second floor? Can the main stack in the attic be tapped into? Does it have to be split in the crawl space? Basically, it would be simple to run supply lines up there but I'm not sure how involved the waste lines would be. I don't want it ready for a bathroom, I just want to be in a position where a full bath can be added without having to rip up anything on the first floor. I've attached a picture to help make sense of my question. Attachment 6037

swindmill 01-20-2014 05:42 PM

Plumber ended up stopping by today. No wet venting here, but he came up with an easy to rough in what we need before the drywall goes up on that wall.

nealtw 01-20-2014 07:37 PM

I think getting the toilet and bathtub drain to fit into the same joist bay. Having a tee built in the wall for the bathtub above may be a good idea.

CallMeVilla 01-20-2014 09:52 PM

1 Attachment(s)
Yes, you can run the waste lines from the attic in the same pipe. You will need to pay attention to the location and avoid cutting floor joists (like most plumbers do) ... this can compromise structure in a very bad way. Better to use bulkheads.

You might give some serious thought to the location of the future bath appliances NOW. Can you cut into the pipe and insert the necessary hub fitting at a later date.

swindmill 01-21-2014 05:33 PM

The plumber, who is actually the homeowners relative, wants to run a separate 3" waste line up there and tie into the main stack (in the picture) from the crawlspace. He said code where we are prohibits wet venting, although it's fine across the river, about 10 minutes from us. He'll run a 2" waste line off the new 3". The joists are only 2x6, so we are hopefully going to leave all the fixtures between the same 2 joists. Otherwise, we will have to drop a hallway ceiling several inches and go underneath them. It seems simple enough that it's worth doing, and putting a master suite in the attic will be a fun long term project.

nealtw 01-21-2014 05:38 PM

Even if you never do it, it would be a plus when selling the house. I wish more people would plan ahead like this.

swindmill 01-25-2014 04:05 PM

1 Attachment(s)
It's great that she has a plumber in the family. He put this in before finished hanging drywall today. Attachment 6056

nealtw 01-27-2014 06:05 PM

The short stud is neet but a block and a scab might have looked better.

swindmill 01-27-2014 06:30 PM

I had torn the existing stud out because it had some rot. The plumber put that up when he was running the new lines. I'm guessing he grabbed the wrong size. I didn't want to make him feel bad, so I left it (gf's cousin). It's covered now, but it will be a head scratcher for the next person to gut this room.

All times are GMT -6. The time now is 11:29 PM.