Expansion noises with plastic pipes

RonV_2

I would like to know what works well for you guys for this problem. I have a boiler vent flue pipe (CPVC, system 636) that passes vertically from the basement up through a main floor 2x6 partition and into the attic. The vent pipe is contacting the wall plate as well as the backside of the drywall (at a joint in the pipe where it is thicker) and the points of contact are generating expansion noises. The most convenient way of eliminating the friction that causes these noises would be to install some sort of sheet material in between the pipe and the wood. Access to the problem is fair, we've cut the drywall open to get at it, but it will be difficult to cut the hole in the wood any larger and the pipe is tight up against it on one side. I have removed the expanding foam firestop to get a clear view of the hole and the pipe passing throught it. I've tried some metal strapping to hold the pipe in a better position in the hole, but the hole doesn't leave much room for this to work well.

I'm wondering what kind of materials would be good for this. I imagine that perhaps a thin sheet of teflon might be good (excellent heat resistance, very slippery). Any suggestions?
Ron

Gilmorrie

Try strips of plastic milk bottles. Anchor on both ends (e.g., with nails) to keep the strips from slipping either way. PVC pipe thermally expands greatly.