Home>Discussions>PLUMBING>toilet drain to vent pipe distance
3 posts / 0 new
Last post
wwchang
toilet drain to vent pipe distance

I'm plumbing in a new bathroom (toilet/sink/shower). This bathroom backs up to an existing bath so most of my plumbing is pretty clustered. I have the sink going up a 1-1/2 inch vent and the shower with a 1-1/2 inch vent with the drain headed towards the toilet.

My question is: The new toilet is using a 4 inch drain and is 7 feet away from the the main vent stack which is also 4 inches in diameter. Is this vent sufficient or is it necessary to get a smaller vent closer to the new toilet drain?

My book says that with a 4 inch drain, the max distance to the vent is 10 feet, but I'm trying to make doubly sure as a 2 inch vent would end up swiss cheesing the (non-load bearing) 2x4 wall that separates the 2 bathrooms.

Thanks inadvance for yer help.

hoffz31
Re: toilet drain to vent pipe distance

Hello,

I am also in a similar situation. My wife wants to relocate a shower and swap locations of the sink and toilet. Can I reuse the existing vent pipe? The vent pipe now handles all 3 fixtures, and is located right off the toilet. Currently, the sink and shower drain past the toilet.

Thanks!

MSSP
Re: toilet drain to vent pipe distance

If you are reading the Uniform Plumbing Code I think what you are refering to 10' is the max distance of a 4" trap arm. The max allowable distance from a toilet to it's vent opening is 6'
Depending on waht code you are using. The International Residential code states that you can put in a studer (quick) vent as long as you have a stack vent going through the roof some where in the house. Hope this helps

TV Listings

Find TV listings for This Old House and Ask This Old House in your area.