Basement Bathroom Venting Questions

[Glimmerman]

New to this, and looking forward to learning lots as I slowly tackle the installation of a bathroom in my basement.

There is no rough-in, everything will be from scratch. The location I have chosen I think is ideal because it is accessible for water supply lines easily, and the drain line is in the floor, in fact the main stack is in the room.

It will actually be a large washroom with the washer & dryer in behind closed doors, so I need to plumb that as well.
The washer is currently in the room, the drain just runs to a floor drain, it is not vented and has been this way for 60 years.

The reading I have done so far is that venting will be a major issue for me, as far as I can tell the only vent going through the attic out the roof is the main stack. There is only 1 bathroom currently in the house, it is just above the main stack.

So my first of many questions is, how do I go about venting my bathroom basement? Is the only choice to run a new vent up by where the main stack is, through the attic and then punch through the roof? I play to have a tub, closet, and vanity downstairs, can they all tie in together, how big of a pipe do I need?

Thank you in advance!

Rory

 

[Jadnashua]

Depending on the size of the existing vent, it may be big enough to add other things to it before it goes through the roof.

The vent line needs to attach to the existing vent (unless you make a new hole in the roof!) at least 6" above the flood plane of the highest drain. That would probably be the top of the vanity sink +6". It could be T'ed in in the attic, if that's easier.

 

[Sponsor]

 

[Glimmerman]

Oh, that sounds promising.

I could get a 2" pipe (I believe this is good enough vent size to handle toilet, sink, tub, and washing machine) and get it up into the attic fairly easily by following alongside the main stack. Does the vent have to be secured every so often? What with?

Then I could get up into the attic and tie my new 2" vent into the 4" copper vent/stack before it exits the roof. What kind of pipe do I use for a vent, and what adapters would I use to tie it into a 4" copper pipe?

The current 4" vent/stack is being used to vent a tub, sink, and toilet right now, nothing else.

 

[Jadnashua]

The 4" is plenty big enough for what you want to do, as (I think) is a 2" for the new stuff. I think you could put some hangers on the pipe in the attic and basically hang the vertical run off of a joist. Horizontally, it needs support, but I think you can go a ways vertically. They make no-hub connectors that can attach copper to pvc. You'll probably have to go to a plumbing supply house to get the right size...the big box stores typically only carry those for pvc-pvc. Since copper costs so much these days, I'd cut a chunk out of the copper in the attic and use no-hub connectors to put in a section of pvc with some stubs and the y to the new stuff. I'm not a pro, so see what they say to confirm I've not overlooked something important. Copper scrap is around $4/pound, so you get the idea what new stuff must be worth.