Drains, grey water, and expansion issues.

Tested draining a bath full of hot water last night and had a fair bit of creaking from the drain pipe. Unfortunately, one run is 3.4m long in 50mm ABS, solvent weld.

Issue 1: The pipe wasn't totally comfortable in the space allocated and went rather tight wedged between the hole in the wall at one end where there's an elbow joint, and the stack at the other end. I can *probably* sort this out if I can open the hole out sideways a bit and give the pipe some more wiggle room.

The other option is some sort of expansion coupling, even a universal rubber washer coupling so the pipe can move into that. Would one normally expect to use an expansion coupling on 3.4m?

I ask, because the kitchen drain is also 3.4m and has more crap jointed on the end, so I don't want to risk redoing that.

Issue 2: Not so important, but slighty irritating. The pipe squeals in its clips rather during movement. What might be a good lubricant? Vaseline would probably work, but is likely to collect mank, ditto silicone oil. Wondered if PTFE spray might work?

and 3: Is there any such thing as a "slip coupling" for waste pipe, for when you need to insert stuff on a pipe that cannot be slid apart because it's fixed at both ends? Google turns up nothing for me...

Tim

I can't help with the first two, but yes, you can buy slip couplings for waste pipe - or in an emergency make one by removing the central stop from a normal coupling. As it happens I did this today (for a larger pipe). I found I was short of a slip coupling for 110mm underground pipework that I was adding a branch to for an extra gully - I totally abused my tools ('cos it was all I could find at the time and I hadn't time to nip out), by putting a parallel reamer in my bench drill, with the "reduced" section level with the seal on the coupling and just held the coupling on it's end on the table and against the reamer, using it as a milling tool. It worked perfectly and only took a few minutes. The extra area in contact as the reamer reached the coupling wall, stopped it digging in any further, leaving a smooth coupling, ready to use.

SteveW