Hello,

I'm installing a new upstairs bathroom and am considering doing the plumbing myself. Would it be possible for you to take a look at the attached drawing to see if I'm on the right track. My primary concern is venting. I was going to tie into the existing vent in the attic well above any fixtures but think it would be better to vent the upstairs bathroom independently. It will tie into the main septic in the basement so I want to make sure the venting I'm considering will work.

Thanks for any help.

If you can tee into your current vent in the attic you will be better off. If you make a new opeing in your roof you are making more work which may allow a roof leak. There is no pressure in the vent stack, it is somewhat forgiving compared to the other work you are doing. Your drawing labels the top as roof but I think from what you say that is your attic, right?

Thanks for the advice,

The roof is the line in the drawing but I do have a crawl space in the attic where I can tee in to the existing vent stack. It will run horizontal approx 30 ft to get to the new bathroom area. I would like to avoid going through the roof with the new vent but wasn't sure if this would give good venting being so far away from the current vent stack.

Venting through roof is always best but sometimes you might need to use a Studor vent.This vent opens when water flows and closes when not.They are a little expensive but work great.Also make sure you use traps as needed to prevent sewer gas from backing up into fixture.Hope this helps?