Sealing a 5-inch CI toilet flange

[Greg Hartley]

I am replacing a toilet for a 5-inch ID (yes, I measured it) toilet flange that is connected to a 4-inch pipe. The depth from the flange surface to the top of the pipe is 2-3/8 inches. I've read about using silicone for the Dutchman fix, but ABS is only 4.5 inch OD - how do I seal the annular gap? This seems too large for silicone. Would a layer of 1/4-inch rubber sheeting (sealed to the ABS OD) work?

 

[Marlinman]

Use oakum followed by lead wool or molten lead. You can find directions on your search engine.

 

[Sponsor]

 

[Greg Hartley]

Use oakum followed by lead wool or molten lead. You can find directions on your search engine.

Thanks! I've never done it before, it looks like you need a lead ladle. I assume that the 4-inch insert should be cast iron.

 

[Marlinman]

Lead wool would be much safer. The oakum is a length of fibrous material that is oiled or tarred. Roll it inside the flange and around the pipe. It needs to be packed in pretty tight. Follow up with the lead wool packing it down as well around the pipe. Most plumbers will heat the lead wool to the point it melts fill any areas that could have been missed and gives it a cleaner appearance.