View Full Version : venting a double vanity with windows above

12-18-2008, 08:52 AM
Hi all,
I am building a new bathroom and have a question on the vanity
It will be a double vanity. The problem is there is a window 8' wide on the back wall of the vanity.I will not be able to run a vent up to the roof
I was thinking of using a loop system as opposed to a aav valve
Can I put the loop in the wall as opposed to in the vanity? I saw a pciture of the rough in for a double vanity on this site/ it looked pretty straight foward

12-18-2008, 09:48 AM
You could use an island vent if there is no other option.
Instead of a santee for one lav, you would use a double fixture fitting.

12-30-2008, 12:37 PM
thanks for the reply is it ok if I put the loop in the wall
the bottom of the window is about 5 feet from the floor
can I run a vent horizontally approx 5 feet to the end of the window and then up to the through the roof
which way would you go with
horizontal vent


12-30-2008, 04:25 PM
A proper vent would be better than a loop vent. If you are able to run that vent horizontally until you can clear the window and then run the line up through the roof, then that would be the way to do it.

A picture of your proposed route would be good.

01-02-2009, 05:31 AM
thanks for the reply
I measured the window and the bottom of the window is 45 inches up from the subfloor
the total width is approx 8 feet with vanity centered under window. i would be traveling approx 4 1/2 feet to right of the window and then up
if i go horizontally from the center of the window. am i usuing 90 degree elbows to the end of the window or 45's and then the pipe would be pitched verticaly towards the end of the window and then up
I am not sure if i have enough room to go with 45's
also at what height should th waist and water supplys be
thanks for the help

01-02-2009, 06:48 AM
you have enough height to do a standard vent. The window is high enough. Since you have the room to route a vent 6" or 7" above the flood rim of the bathroom sink. Just route the vent horizontally (with a minor slope to the drain) over to where you Can go vertically.


01-02-2009, 07:32 AM
thanks for the info
am i assuming correctly that i would use a 1 1/2 pvc for the vent ubove the 4way tee?

i am mounting a toilet to the right of the vanity
Does a toilet need a vent and if so can I tap into the 1 1/2 vent line or does it need a larger vent size of 1 1/2