[ehoff]

How do I replace the lead toilet flange into a cast iron main stack? Is it difficult? Hesitate to do the work myself, afraid of a leak down the road. Many thanks for your suggestions, directions!

[massplumber2008]

Hey Ehoff:

A professional should cut old lead pipe and then melt out old lead joint, install a PVC manhoff fitting and oakum material into the bell of the cast iron fitting and then pour a new lead joint. From here new PVC elbow, pipe and flange. This can be very dangerous and is best left to a pro.

A homeowner is probably best to cut the lead pipe at the swelled area of the lead pipe (use sawzall with bimetal blade)... just before the lead pipe enters the cast iron fitting. This is a brass fitting (leading ferrule) that allowed the lead to be melted/wiped/joined to the cast iron fitting. For now, cut in front of the swelled area of the lead pipe. Examine the brass fitting and then cut the fitting where the lead best joins so that you can use a shielded clamp (see picture) to transition from this fitting to PVC.

If the fit is not good at the brass ferrule/fitting then you may need to mess around with shielded clamp sizes... may even need to melt the lead off the brass ferule itself and then make connection.

This can be a tricky fit/job to do.. so if want guarantees of no leaks then you may want to consult a pro. Here.

You can also try to cut the lead pipe behind the turn up and see if you can attach a clamp onto the lead pipe itself. Try this first if you have time to mess around. Cut lead pipe at ferrule second and then opt. for the plumber if necessary.

Finally, if you have a small hole in the lead pipe then you may be able to PATCH the lead pipe using a plumber's epoxy or JBWELD epoxy... see this site... www.jbweld.com This can be good option if looking to delay a remodel a year or so... :)

You would order a 4" shielded clamp, a 4" x 3" pvc reducing bushing, 3" pvc pipe, and a 4"x3" pvc closet flange, and cement and primer. Include a new wax gasket, a pair of 5/16" johnnie bolts, and a squeeze tube of caulking to caulk around 3/4 of the base of the toilet if you want a crisp, finished look... ;)

Let us know what you think...

MARK