1st post here, been searching but I can't find my answer.
Our house is in WI, ranch, 1 bath, kitchen, and laundry.
Currently has 4" cast iron into the basement, previous owner converted to 4" pvc right where the sewer line enters the house. The 4" is continuous up through the roof. This is the only roof penetration for venting
We are moving the location of everything in the house so all the pvc will be replaced. I want to use 3" for this but the cross sectional area of the main drain requirement for venting is throwing me for a loop...
Can I reduce to 3" where the previous owner converted over to pvc, including for the vent through the roof? I would keep a 4" cleanout at the floor level in the basement right above the conversion from cast iron to pvc. I would then convert to 3" for inside the house, including the vent through the roof.
Or do I need to use 4" because that is what is going out to the street/sewer?
Thanks!
Our house is in WI, ranch, 1 bath, kitchen, and laundry.
Currently has 4" cast iron into the basement, previous owner converted to 4" pvc right where the sewer line enters the house. The 4" is continuous up through the roof. This is the only roof penetration for venting
We are moving the location of everything in the house so all the pvc will be replaced. I want to use 3" for this but the cross sectional area of the main drain requirement for venting is throwing me for a loop...
Can I reduce to 3" where the previous owner converted over to pvc, including for the vent through the roof? I would keep a 4" cleanout at the floor level in the basement right above the conversion from cast iron to pvc. I would then convert to 3" for inside the house, including the vent through the roof.
Or do I need to use 4" because that is what is going out to the street/sewer?
Thanks!
Last edited: