15mm PEX Through Joist All aspects of plumbing questions and answers, help, tips and information

[gjran23489]

Hi folks,

I am re-plumbing the heating system in my flat and have chosen to do it in PEX. In order to get to a radiator, I need to go through two joists. I've worked out and drilled the holes already but my question regards how the pipe should go through the holes.

I drilled 20mm holes, and sleeved the pex in some old 20mm polypipe from the old system. This sleeve is pretty snug around the 15mm pipe and in the drilled hole. It doesnt really allow for any movement.

Will this be okay or will this cause the clicking noise during expansion/contraction? If so what should I do to sort it out?

Many thanks in advance for any replies.

[stoneyboy]

Hi jgran23489,
Plastic pipe expands a lot when it gets hot so suggest you enlarge the holes so there is free movement. Bear in mind that if there are fixed ends on the pipe the straight run will become a snake.
Regards S

[gjran23489]

Hi and thanks for the reply,

I will look to enlarge the holes for expansion, is there anything you would recommend to sleeve the pipe with as it goes through each joist to protect it? Or is the larger pipe I have sleeved it in fine?

Thanks

[stoneyboy]

Hi gjran23489,
I don’t think there is any advantage in sleeving through timber joists, but if you go through a masonry wall sleeving is essential.
Regards S