If the carpet roll has sat too long in storage or had rolls stacked too high on it, the weight will compress the carpet face resulting in what is called Roll Crush. Roll crush or pole crush rarely occurs at the manufacturing level since rolls are stored one roll in height at the mill. As a result, roll crush is usually not considered a manufacturing defect. Consequently, carpet manufacturers will often blame everyone else and refuse to fix the problem.
But, some carpet retailers store rolls at heights of three or more rolls! Roll crush also may occur during shipping where rolls are loaded several rolls high.
Carpet Roll Crush marks appear as wide bands across the carpet width and are easily identified since they are not evenly spaced but are progressively spaced closer as the carpet roll gets closer to the center.
How to Fix Roll-Crush:
In Nylon Carpet, roll crush marks often come out over time with heat and humidity especially in the summer - if the carpet was properly power stretched in place rather than knee-kicked in. If stubborn, they can usually be forced out by steaming with a “Jiffy Steamer” or by having the carpet hot water extraction cleaned. Sometimes, a pile lifter will help.
Polypropylene (Olefin) Carpet is a different story. Since polypropylene fiber has zero resilience, once it is crushed, it will not come back up - not even with steam.