Our plumber wants to install a cleanout for the washing machine drain vent pipe.
How do I do this?

If it's a vertical run of cast iron, you have the problem of tremendous weight coming down from above. Talk to your plumber.


Horizontal you can generally just sawzall out a section and add 2 short pieces of PVC with the cleanout and the washer drain in the middle, and attach it to the iron with 2 steel-clamp rubber connectors (Fernco is the typical brand) Then you want metal strap hangers to hold up the iron on either side.

If the plumber wants to do it let him. You need to support the heavy piping, cut it and add a cleanout section. Cast Iron is not easy to cut without the proper tools.

Your plumbers biggest problem will be supporting the cast iron stack after he makes a cut. This can be accomplished with a raiser clamp and two 2X4s cut to size, (see image) I make my cuts with a set of ratchet cutters. Good luck Tom