On a rare occasion after I have cleaned residential wall-to-wall carpet, the carpet in one or more rooms will quickly develop some ripples/humps. I assume the carpet has stretched/expanded. I explain to the customer that the ripples should disappear once the carpet has dried completely. I have never heard back from a customer that the ripples did not disappear.
I use the Challenger, 2 gal sprayer and cotton pads.
Has this ever happened to any of you? Am I over spraying? Are my pads too wet? Can the Challenger cause this? Is it the condition/quality of the carpet?
I would appreciate any thoughts/input that can help me avoid this in the future. Thanks

This can happen from too much moisture, but it is nearly impossible to put down this much moisture when you are OP'ing, unless you are emptying your sprayer with great frequency. Before switching from VS Dry Foam to OP cleaning, I had this happen occasionally. I would tell the customer what you have been saying. No one ever called back to say that the wavy condition continued.