Does SPC rigid flooring need an expansion gap?

[Timanfiya]

Hi all.
I'm a bit confused as I have read that SPC does not expand and does not need to acclimatise due to it being stone/plastic composite rather than wood/plastic composite. However, on searching installation they all seem to say to acclimatise and leave an expansion gap? Can anyone explain?
I'm fitting pvc wall panels over the top so should be OK for up to 8mm gap but I'd like to understand if the gap is needed and if so, why if it doesn't expand?
Thanks

 

[Why Not Indeed]

a) Different materials have different coefficient of expansion. That of timber is so great that you need to leave a gap. That of stone, apparently isn't. Or maybe is.
b) Regardless of what the theory says, if the manufacturer says it needs an expansion gap, then you should probably assume that it needs an expansion gap.

 

[catlad]

Plastic will expand!

 

[Timanfiya]

I have followed the guidance for 7mm gap from manufacturer. Just don't quite understand if it supposedly doesn't expand. Who knows ‍

a) Different materials have different coefficient of expansion. That of timber is so great that you need to leave a gap. That of stone, apparently isn't. Or maybe is.
b) Regardless of what the theory says, if the manufacturer says it needs an expansion gap, then you should probably assume that it needs an expansion gap.