I need some help, I am installing a toilet and sink that is about 20 feet from the stack in a basement. Main drain is under concrete floor. There is no rough in so I need to break the concrete. My question is how do I vent the system. Can I just run a vent over to the stack?

Nope, you will need to run a vent up and tie it into a two inch or larger vent at least six inches above the highest fixture, or take it all the way up and out through the roof. If you are only installing a toilet and sink, you will be able to use the toilet vent for sink drain, and then continue the vent up.

Does this mean the highest fixture in the house or in the basement?

Hi all...

Here's a quick visual to back up what MGD77 suggested therenovator... see image.

You asked if this meant the highest fixture in the house or in the basement. Depends, the vent cannot connect back into the stack if any fixture connects into the stack above this 1/2 bath.

Let us know what you think...

MARK

Thank you both for your help, I understand it now. I have to bring the vent up because there is 2 baths above on that stack, I think the easiest is to bring it to the attic and connect up there. Thanks again!

All right, sounds like you have a plan,, Marks drawings help immensly don't they... Lee.