Inaccessible pipe: clipping vs support

[phloaw]

Hi, I managed to push two 15mm pex pipes through the underfloor space of a second floor. They go (on a straight run between two parallel joists) from a hole in the floorboard (18mm thick) under an existing radiator to another hole in the contiguous room's floorboard, ready to attach a new radiator.

Therefore, the pipe portion in the roughly two metre distance between the two holes is currently inaccessible, and merely rests on the lower floor's ceiling.

 

Would that be enough support? Or should I add clips along the inaccessible part to avoid problems on the long run?

 

Thanks.

 

PS: I can add a lagging sleeve to the inaccessible pipe portion, if that helps.