I'm installing a double sink. The basins are 20 gallons each and the
drains are about 8" apart. I will be installing a 1.5" PVC vent
around the room near the top of the studs to serve all the fixtures.
There are two ways to connect the sink drain--a single trap or
separate traps for each basin. If I install separate traps, I could
install a separate vent for each trap. I want to eliminate any
possibility of waste water draining from one basin to enter the other
(empty) basin. What is the best configuration?

On Dec 22, 11:35�am, Phisherman wrote:
I'm installing a double sink. �The basins are 20 gallons each and the
drains are about 8" apart. �I will be installing a 1.5" PVC vent
around the room near the top of the studs to serve all the fixtures.
There are two ways to connect the sink drain--a single trap or
separate traps for each basin. �If I install separate traps, I could
install a separate vent for each trap. �I want to eliminate any
possibility of waste water draining from one basin to enter the other
(empty) basin. �What is the best configuration?

seperate traps always better. are you certain a 1.5 inch vent is
enough?

On Sat, 22 Dec 2007 09:07:42 -0800 (PST), "
wrote:

On Dec 22, 11:35?am, Phisherman wrote:
I'm installing a double sink. ?The basins are 20 gallons each and the
drains are about 8" apart. ?I will be installing a 1.5" PVC vent
around the room near the top of the studs to serve all the fixtures.
There are two ways to connect the sink drain--a single trap or
separate traps for each basin. ?If I install separate traps, I could
install a separate vent for each trap. ?I want to eliminate any
possibility of waste water draining from one basin to enter the other
(empty) basin. ?What is the best configuration?

seperate traps always better. are you certain a 1.5 inch vent is
enough?


Not sure. The area is already plumbed with a 2" drain and 1.5" vent
(for a bathroom). My intent is to install a large shower and laundry
hookups as well. This house was built in 1992--does current plumbing
code require 2" vents? If so, I'm concerned about drilling holes
through the studs which are only 3.5" wide. 2" PVC will require 2.5"
holes through these studs.

On Dec 22, 2:02�pm, Phisherman wrote:
On Sat, 22 Dec 2007 09:07:42 -0800 (PST), "

wrote:
On Dec 22, 11:35?am, Phisherman wrote:
I'm installing a double sink. ?The basins are 20 gallons each and the
drains are about 8" apart. ?I will be installing a 1.5" PVC vent
around the room near the top of the studs to serve all the fixtures.
There are two ways to connect the sink drain--a single trap or
separate traps for each basin. ?If I install separate traps, I could
install a separate vent for each trap. ?I want to eliminate any
possibility of waste water draining from one basin to enter the other
(empty) basin. ?What is the best configuration?

seperate traps always better. are you certain a 1.5 inch vent is
enough?

Not sure. �The area is already plumbed with a 2" drain and 1.5" vent
(for a bathroom). �My intent is to install a large shower and laundry
hookups as well. �This house was built in 1992--does current plumbing
code require 2" vents? �If so, I'm concerned about drilling holes
through the studs which are only 3.5" wide. �2" PVC will require 2..5"
holes through these studs.

could transistion thru studs to copper or other thin wall material
just thru studs.

we need a plumber here, with all the new stuff your adding 4 inch main
vent might be necessary.


venting prevents siphoning of traps.

with such a small vent diameter showering while doing laundry might
suck the other traps dry, allowing sewer gas into home. I have a old
friend who found natural gas in his home, after a leak a quarter mile
away got in the neighborhood sewer line and somehow found its way into
his home.

he opened door and left. smart fellow a retired fireman.

he had a cracked main trap and a leaking sink trap, leaving a nice
escape path for the natural gas. his home could of exploded.

you getting a permit for this work? if not it might come back to haunt
you at home resale time.

On Sat, 22 Dec 2007 12:54:38 -0800 (PST), buffalobill
wrote:

On Dec 22, 11:35 am, Phisherman wrote:
I'm installing a double sink. The basins are 20 gallons each and the
drains are about 8" apart. I will be installing a 1.5" PVC vent
around the room near the top of the studs to serve all the fixtures.
There are two ways to connect the sink drain--a single trap or
separate traps for each basin. If I install separate traps, I could
install a separate vent for each trap. I want to eliminate any
possibility of waste water draining from one basin to enter the other
(empty) basin. What is the best configuration?

buffalo ny: who/what/where/when/why/how:
who is stopping you from reventing to the 4" soil stack?

There is no 4" soil stack.

what is the trap size don't go bigger than the kitchen 1-1/2" or the
draining will fight an oversize trap.
where are we, in the kitchen?

Basement.

when you run all the fixtures simultaneously in the house thru a slow
sewer
why not check the local requirements, sometimes for the cost of a
plumbing inspector will get you amazing info to help you.
how far above/below grade, how much water is pumped out so much faster
on many of the newer machines, how much pitch is needed on your
upcoming addons and so on.
first look at:
http://www.free-ed.net/sweethaven/Bl...p?iNum=fra0309
second, see good vent specs at:
http://www.oatey.com/apps/catalog/in...tion_Sheet.pdf
general description info and links at:
http://en.wikipedia.org/wiki/Plumbing_drainage_venting
and see:
http://www.theplumber.com/index.html

Thanks for these links.

wrote:

On Dec 22, 11:35�am, Phisherman wrote:

I'm installing a double sink. �The basins are 20 gallons each and the
drains are about 8" apart. �I will be installing a 1.5" PVC vent
around the room near the top of the studs to serve all the fixtures.
There are two ways to connect the sink drain--a single trap or
separate traps for each basin. �If I install separate traps, I could
install a separate vent for each trap. �I want to eliminate any
possibility of waste water draining from one basin to enter the other
(empty) basin. �What is the best configuration?


seperate traps always better. are you certain a 1.5 inch vent is
enough?
Hi,
When I look at ours in the kitchen one trap with 2" vent.
We have a dish washer and garburator as well draining into it.