View Full Version : basement bathroom

12-30-2004, 05:56 AM
I am planning to remodel my basement in a new house (2 years old). The basement has plumbing stubs for a full bath. My question is regarding venting each fixture. There are 4 PVC pipes in the basement floor. 3 are for the shower, toilet and sink drains. The 4th, a vertical 3" pipe that has a flaange on it just above the floor, and has a cover that is screwed into the pipe. I thought that this was a cleanout, but now am wondering if this is a vent for the shower and toilet.

The location of this 4th pipe is located within about 5 feet of both the shower and toilet pipes, but is also right next to the main incoming water line. If this is a vent pipe, than there is no seperate cleanout pipe.

I have two main drain lines that go into the basement floor. Each one has a Tee in it near the floor with a plug screwed into the Tee. Would these be considered the cleanouts?

There is also a 1 1/4" PVC pipe that extends through the basement celing from the first floor that is not connected to anything. It is capped with an orange slip on cap. I believe that this is extended down from the vent pipe for the sink in the first floor bathroom.

Can I connect the basement bathroom vent pipe to this? The reason I ask is that every diagram I've seen shows that you should tap into an existing vent pipe above any existing fixtures. If I connect to this pipe, I think that I would be tapping in below the first floor bathroom sink.

I know there is a lot here, but thanks in advance for any help anybody can give me.

12-30-2004, 01:44 PM
I'm not a pro, but I think that 1-1/4" is small for a vent line...not sure what it is. If it is a vent, it may be a tap off of the vent system from above - it should tap off of that system above the water line of the fixtures in those rooms, and if it does, other than the size, it should be okay.

01-05-2005, 06:59 PM
The cap on the floor is probably the access for a backwater check valve for the basement fixtures. Take it off and see. There should not be a stub up for the shower. We don't know where they will exactly be located so it's usually a horizontal pipe capped under the floor. Should be a sand box right under the concrete. Pour water in the pipe to see if it has a trap. If it doesn't hold water then it's a vent pipe for some of the basement fixtures. The pipe coming down from the upper floor with the orange cap is to tie the basement vents into. Check again. It should be a 2" interior diameter pipe.

01-05-2005, 07:20 PM
A picture's worth a thousand words.....

I'll bet we could figure this out alot faster is you could post a picture.
Some locals allow a 1-1/2" vent for a bathroom group, but not 1-1/4 and I do not believe that they even make 1-1/4" DWV PVC and fittings.
The Pipewench

01-05-2005, 07:37 PM
Deb I think they do make 1 1/4" DWV/PVC. Most sump pumps have 1 1/4" outlets and I have pipe and fittings in 1 1/4".

01-06-2005, 06:01 AM
I remeasured the vent pipe. It is 1 1/2" ID. There was a small puddel of water on the floor under the vent pipe. It has been snowing a lot here. Not sure if snow is making its way down the vent to here or if it is coming from somewhere else? Should I be concerned?

Pictures are attached. I did not try pouring water into the pipe becasue I could not easily remove the cap on the pipe. The pipe in the corner with the orange cover is 3". I assumed that was a drain for a shower.

For reference, the picture showing the pipe behind the shelves, is located on teh right side of the picture showing the general layout of the plumbing.

01-06-2005, 07:49 AM
The water from the vent pipe wouldn't concern me. I usually get some and presume it's from condensation but it could be from the roof. I'm still inclined to think the cross plug is an access for a backwater valve that needs to remain accessible. I will be interested in what you see when you take it out.
You could be right about the orange cap being a shower opening. We do not rough them in that way in my area but it could be possible. We usually rough in tubs unless it's specified for a shower. Tub boxes are usually a foot and a half or two foot off an exterior wall. Yours looks in quite a bit. You can cut off the cap and then reclose it with a rubber cap with clamp.
I have no clue what that 3" pipe is stubbed up in the stud wall under the gatorade. I would like to know what it is. Plumbing mysteries.

Dale's Plumbing Service,
01-06-2005, 05:04 PM
The 3" pipe (using the UPC code is probably a wet vent as it will probably pick up the lav. But the UPC calls for a 2" vent on the toilet. so then that means the 1-1/2 vent from the ceiling is too small. But the IPC code says it is OK. so in any event it will all work.
That 3" in the floor may be a clean out but as the other folks say it may be a back water valve.
You may have to ask the plumber who roughed this in what shower base he intended to use. hope you find the one to fit that rough-in
Dale :) :)

01-07-2005, 03:18 AM
To clarify. The pipe on the left with orange cap (in the general layout picture) is a 3" pipe. I took of the cover and there is standing water in it about 10" below the level of the floor. I probed around with a stick, and it feels like a trap at the bottom.

The pipe in the stud wall with orange cap (under the gatorade) is a 2" pipe. I took the cap off. There is no standing water in is. The is an elbow at the bottom that heads in the general direction of were the pipe that may be the backwater valve.

I did not open the cover on that yet. Will try that today, and let you know.

01-08-2005, 06:03 PM
I was not able to get the cap of the pipe by the water line. It looks like it takes a special tool to unscrew the cap. There are slots in the cover in a cross (+) configuration. Both the flange and the cap say "4 rectorseal tomcap". Maybe that means something to someone.

Based on the pipe by the water line being a backwater valve, here is how I figure I need to plumb everything. The shower pan goes on the 3" pipe on the left side of the picture. The toilet goes in the middle. The sink drain attaches to the 2" pipe in the stud wall (under gatorade). Connect the 2" pipe in stud wall to the 1 1/2" vent pipe down from the basement ceiling.

I plan to make a closet in the bathroom to enclose the main water line/shut off, and the backwater valve cap. Depending on the size shower I end up with, I will need to build the closet wall very close if not on top of the backwater valve cap. Any concerns about building a wall close to or on top of that cover? The inside of that closet would not be finished.

Thanks for all that helped out!

01-09-2005, 10:57 AM
Do not build a wall on top of or extremely close to the access for your backwater valve. You will almost certainly need access at some point in the future.
The Pipewench

01-15-2005, 11:39 AM
On another forum about the shower only the poster has talked to his inspector and the plumber and they say the 3" PVC pipe is a tailpiece and has a trap below slab and thgis pipe is for the shower. That the poster can install a 2" shower drain with tailpiece and just stick it down into the 3" pipe without sealing. That this is okay and is an indirect drain. The poster is in a town in Wisconsin.
What am I missing here? How can you have an indirect drain you cannot see?