This is my first post, hopefully I am posting in the right section.
I recently bought an old condo with all steel pipes and cast iron drains. I have a first floor and second floor bathroom, and the vertical drain goes down through the basement floor. I would like to replace all the drains with PVC. I've read with more than one toilet, you need a 4" drain, and currently, both toilets are draining into the single 3" cast iron. My question is, unless I'm breaking up the concrete to get to the junction below is there any point to going to 4" PVC? Would replacing the 3" cast iron with 3" PVC be a code violation? Thanks.
I recently bought an old condo with all steel pipes and cast iron drains. I have a first floor and second floor bathroom, and the vertical drain goes down through the basement floor. I would like to replace all the drains with PVC. I've read with more than one toilet, you need a 4" drain, and currently, both toilets are draining into the single 3" cast iron. My question is, unless I'm breaking up the concrete to get to the junction below is there any point to going to 4" PVC? Would replacing the 3" cast iron with 3" PVC be a code violation? Thanks.