What is the building code for cleanouts which extend through a fire wall into a garage area? My inspector came out last week and indicated I should change a 3" ABS downswept Y from the 2nd story, to a cast iron one. Can I just use a 3" cast iron/galvanized nipple with a 3" cast iron coupling and thread them into the 3" ABS cleanout? I will have to fur the wall out for this extension before drywalling, but I would have to fur out the wall anyway if I replace the ABS Y with cast iron, since CI fittings are larger dimensions.

I can provide a picture if it is necessary for clarity, Thanks, Iggy

 

Call your inspector he will tell you one way or the other, he is there for guidance and will be happy to let you know.

 

Plumber 2000,
Thanks! I did call him and I can do it as I described. I guess the code says that the fire rated drywall must have cast iron at the point of penetration, which is what I thought was the point of his directive while on the job site. And your right, he was "happy" to help me.