Hi Guys
I'm pretty sure rippling is due to the water 'plasticising' the adhesive/base causing it too expand.
Plasticisationn occurs when a small molecule fills the spaces between large molecules causing them to be pushed apart.
The carpet returns to it's original condition once the carpets water levels have returned to normal.
Why are some carpets more prone to this ?
Well different adhesives/substates are used and even if the same adhesive is used then there will be variations , particularly if quality control is poor.
I have never know a rippler not to return to its original dimensions but it is not pleasant.
Cheers
Doug