I heard you could not use a fernco horizontal. If this is true, then what do you do when installing another line to an existing say under a concrete slab. You have to cut the pipe to accept the new fitting, then you must cut the piece for the other end 1-1/2" shorter so you can get it into the hub. Thus when you push it on you wind up with a 1-1/2" gap. A no hub band would hold the pipes together better and prevent sag, but they are only 2" wide which means you only have 1/4" on each end of the pipe. Even if you use a slip coupling you only wind up with 3/4" over each end. What do you do?