Over restrained waste pipe

[JFDIY]

I've seen loads of waste pipes that sag between supports, so I've packed and strapped mine to all the joists at 400 ctrs.

 

However I'm now wondering if I've over restrained them from thermal movement, it's all solvent weld, the run is 1.5m of 50mm then another 1.5m of 40mm to an AAV.

 

Don't want it breaking the joints, but solvent weld is mega strong to I'm probably over thinking it.

 

 

 

[ProDave]

I didn't strap mine.  I supported them at frequent intervals with a piece of batten under them for them to rest on, so they won't sag, but are free to expand and contract.