Why do my pipes creak 10 minutes after using them?

Question

Our recently installed bathroom uses existing pipes that were previously plumbed into cut out sections of joists, with no cladding.

Approximately 10 minutes after use there is a quite loud creaking.

We were advised this was because of the absence of cladding, and that quick solution is to use expanding foam in between the pipe and timber joist, to act as cladding. this avoids the much bigger job of completely refitting pipes and pulling up floor/re cutting joists.

The pipes are easily accessible at the moment as we are renovating (we have the ceiling off in the room below bathroom, but the bathroom itself is all tiled up).

Will this work, any other ideas?

Answer 1

I don't see why not.

The creaking is caused by the pipes rubbing on the joists as they expand and contract when first the pipe heats up as hot water runs through and then cools down as the water left in the pipe cools down.

If you wrap the pipes in insulation this will have the dual effect of stopping the creaking and keeping the hot water in the pipes warmer for longer.