Venting a new basement bathroom

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tollhaus

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Jul 26, 2020
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Location
Crofton, MD
Hello, I'm starting the work on my basement bathroom which was roughed in when the home was built in 1988. I bought it a year ago and am going to start finishing the basement. I'm going to hire a plumber to do all the plumbing work, but before I start the framing, I want to figure out what my venting options are.

There are two 2" drain pipes (shower and vanity) and one 4" pipe (toilet) sticking out of the floor. These all go to the pit that is a few feet behind where the wall will be. From what I can tell, there is not a vent line roughed in. Everything is under the slab and the three pipes converge on the 4' pipe into the pit.

The drain line is easy: I plan on using a pump to get to the main drain line which runs along the basement ceiling right next to one of the new bathroom walls.

Can I vent off of the vanity drain for the shower, toilet, and sink? Or will I need to tear up some of the floor to get a vent line in there? Or is there a way to vent off the "pump stack" (not sure what to call it) so I'd basically vent out right before the drains hit the pump? Or can I vent AFTER the pump, on that vertical run up the main drain of the house? (I'm assuming after the pump is a non-starter, but it'd be the easiest.)

Then as for options of where to vent, I could get right next to the radon remediation system and run a pipe right up along the exterior wall next to the chimney. Or, I could easily get a 2" vent into the garage and out a sidewall. Is either of those options ok? Or, I guess I vent to the kitchen vent, wherever that is. (Basement is completely unfinished now, so I can find it.)

Thanks!
 
tollhaus said:
Hello, I'm starting the work on my basement bathroom which was roughed in when the home was built in 1988. I bought it a year ago and am going to start finishing the basement. I'm going to hire a plumber to do all the plumbing work, but before I start the framing, I want to figure out what my venting options are.

There are two 2" drain pipes (shower and vanity) and one 4" pipe (toilet) sticking out of the floor. These all go to the pit that is a few feet behind where the wall will be. From what I can tell, there is not a vent line roughed in. Everything is under the slab and the three pipes converge on the 4' pipe into the pit.

The drain line is easy: I plan on using a pump to get to the main drain line which runs along the basement ceiling right next to one of the new bathroom walls.

Can I vent off of the vanity drain for the shower, toilet, and sink? Or will I need to tear up some of the floor to get a vent line in there? Or is there a way to vent off the "pump stack" (not sure what to call it) so I'd basically vent out right before the drains hit the pump? Or can I vent AFTER the pump, on that vertical run up the main drain of the house? (I'm assuming after the pump is a non-starter, but it'd be the easiest.)

Then as for options of where to vent, I could get right next to the radon remediation system and run a pipe right up along the exterior wall next to the chimney. Or, I could easily get a 2" vent into the garage and out a sidewall. Is either of those options ok? Or, I guess I vent to the kitchen vent, wherever that is. (Basement is completely unfinished now, so I can find it.)

Thanks!
Click to expand...
Either draw a picture or take a picture., prefer tou to draw what your doing., and I'll be able to assist you easily.

You have to list the size of the vanity sink vent., is it 2 inches? Do you have a vent stack or something? Take a picture first and list the pipe sizes
 
Generally speaking, a 2" vanity drain is intended to be the wet vent to vent the whole bathroom group. If this was roughed in when your house was built, they SHOULD have tucked a vent somewhere. Any capped pipes coming down near there? Any vents off a floor drain or something they left to tie into?
 
1642529368848.png
Thanks for the help. There isn't a whole lot to draw, because I'm (a) not good at drawing) and (b) not sure where any vent stacks are in the house.

Bottom line: the three pipes in the drawing are under the slab, but there are no vents roughed in from under the slab. So I'm looking for options. I will hire a plumber (he's already been over to help me identify the rough ins and understand the layout so I can buy the toilet, shower pan, and vanity). I'm doing the framing now and just want to get a good feeling that we won't need to tear up the framing and put vents in under the slab. I guess I just really want to make sure the plumber doesn't come back and say, "Oh, I assumed there was a rough in for a vent here."

So with that said. Can we (1) use the sink vent as a wet vent and go straight up to the ceiling with it to join a vent stack above or (1a) get out to an exterior wall or (2) vent out of the pit as he installs the ejector pump?

Thanks!
 
Helper Dave said:
Generally speaking, a 2" vanity drain is intended to be the wet vent to vent the whole bathroom group. If this was roughed in when your house was built, they SHOULD have tucked a vent somewhere. Any capped pipes coming down near there? Any vents off a floor drain or something they left to tie into?
Click to expand...

I haven't seen one roughed in or capped. The ceiling is all open right now, so I assume that the plumber would be able to find the vent for the kitchen sink and vent up through that, right? That's about 15' away from where the vanity will be.
 
tollhaus said:
View attachment 33220
Thanks for the help. There isn't a whole lot to draw, because I'm (a) not good at drawing) and (b) not sure where any vent stacks are in the house.

Bottom line: the three pipes in the drawing are under the slab, but there are no vents roughed in from under the slab. So I'm looking for options. I will hire a plumber (he's already been over to help me identify the rough ins and understand the layout so I can buy the toilet, shower pan, and vanity). I'm doing the framing now and just want to get a good feeling that we won't need to tear up the framing and put vents in under the slab. I guess I just really want to make sure the plumber doesn't come back and say, "Oh, I assumed there was a rough in for a vent here."

So with that said. Can we (1) use the sink vent as a wet vent and go straight up to the ceiling with it to join a vent stack above or (1a) get out to an exterior wall or (2) vent out of the pit as he installs the ejector pump?

Thanks!
Click to expand...
I'd use a sanitary tee on the sink and run that vent to either the roof., or to the vent stack, and you're good to go.,

Imo
 
Thanks. I assume I also need to vent the ejector pump pit, right? Tie into the same vent line heading upstairs?
 
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