Securing new CH pipes to avoid expansion noises

[endecotp]

Dear Experts,

What's best practice for fixing central heating pipes so they don't make noise due to expansion and contraction?

I'm re-fitting copper CH pipes under a groind floor to which I'm adding insulation. The construction of the floor will be existing concrete slab, 70mm celotex, then a floating wooden floor. Where the CH pipes go I'll reduce the insulation to 25mm leaving a 45mm space for the pipes (i.e. 15mm pipes in 13mm insulation).

The pipes could simply lay in this space without any fixings. Is that what I should do, or should I secure them somehow?

Thanks!

 

[John D v2.0]

Probably best chance of no noise if you give them freedom to move. As long as no strain on the joints.

 

[dilalio]

Lag them in felt... this provides sound proofing as well as insulation and allows unfettered movement within