Basement Bath & Kitchen Venting
Posted by Ed P. on May 21, 2003 at 17:19:35:
Hi everyone. This is a great board! Thanks to all who respond!

Here's my challenge.

We want to install a basement (full) bath and a kitchenette with sink.

#1. May I use Air admittance Valves for each of
these fixtures instead of running separate vent
line(s)? (AAVs are code compliant in Ohio)

#2. Re-drain lines. Which of the following would work

Running separate branch drains - 1 (3") for the
closet and another (2") for the tub, and
lavatory. This method would place the water
closet downstream from the other fixtures.


Otherwise all fixtures would need to be
rearranged on the floor plan, to keep the
watercloset downstream from the others.

The third option (sorry I have not done my
homework - probably NOT an option -thought I'd
ask anyway)

Keep the watercloset according to plan but
use a wall-mounted fixture and use four
closets bends and about 22' 3"inch pipe
keeping drain pipe sloped above the floor
running the perimeter behind a wet wall
until the tie-in point in the floor drain.

This would keep the watercloset
downstream from the other fixtures.

This sounds so far-fectched, it
probably is not permissable. Doesn't
hurt to ask does it?

Current stats: Bath and Kitchenette would
be tied into 3" basement floor drain.
This existing drain receives wastes
from main floor Kitchen sink,
dishwasher, washing machine, laundry
tub as well as a lavatory, shower
and water closet.

This (existing) 3" drain system is vented
above the watercloset 3" to the
roof and the washing machine also has a 2" vent
to the roof.

Would the 3" basement drain handle the new four
fixtures described above along with the present

Or would it be better to run a new (3")
branch drain to the main cleanout
(4" pipe)?

Thanks again. Much appreciated!

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