: Hello!

: I posted previously about relocating a shower drain and decided to bust out more concrete. Turned out nicely. Thanks for your help.

: The question I have is what is the correct way to install a Fernco coupling? Do the pipes have to butt up to each other and then the Fernco slides over the connection? Or can there be a gap between the pipes (1.5") when the Fernco is slid over the pipe ends? I'm installing a wye.

: I spoke with Fernco and they seemed to think that the gap would be okay, as long as there was a minimum of 1" of overlap onto the pipes. The plumbing supply place thought the same. However, I have read elsewhere that there should be no gap and that the two ends of the pipe should butt together. This would require the use of two Ferncos.

: This is a 3" waste drain line. Does that 1/4" lip in the pipe create a problem?

: Thanks!

: Mike