Questioning the Need for Pipe Insulation
1/2″ pex supply lines will be installed in interior partition walls that are insulated with 4″ rockwool safe ‘n sound. My well water water is cold year round, and the copper in my current cabin sweats in the summer even though it’s wrapped with neoprene foam, although it’s exposed and not in the walls.
Will the wall insulation as well as the quality of my conditioned home and the pex tubing eliminate the need to use pipe insulation on these in the wall runs?
Thanks, Daniel
GBA Detail Library
A collection of one thousand construction details organized by climate and house part
Replies
The rockwool might help a little, but it's vapor open so you can still get condensation on the pipes themselves, even with the rockwool wrapped around the pipes. I would put the split foam type pipe insulation on, and I like the stuff with pre-applied adhesive along the cut so that you can seal it around the pipe at installation time. Do this prior to putting in the rockwool, and tape the sections of pipe insulation together (typical insulation sections are sold in 5 or 6 foot pieces). With the pipes insulated in this way, you should be OK in terms of condensation staying under control.
BTW, I insulate water lines in my own home the way I just described and it does make a big difference. I do the same for hot water lines, where the insulation helps to get hotter hot water at distant fixtures.
Bill