We want to Limit the number of Roof penetrations and want to combine some of
What are the rules for taking say, 1.5, 1.5 and a 2" line and upsizing them
to a 3" and venting the 3" out the Roof?
From what I've read you can downsize your Vent one size for your Drain. So a
1.5 Drain you can use a 1.25 Vent? So for most of ours we have vented the
Same Size if that makes a difference when we upsize in the Attic.
Our Exit line to the Septic Tank is 3". We do not have a 3" from the main
trunk line drain to a vent, they are all just the vents from sinks, showers
and Toilets. 2" and Smaller.