Clouding or fogging occurs when there is a break in the inner seal between the glass panes, which causes condensation to form between the two panes.
All of VELUX's units manufactored after January 1, 2000, have a 20-year seal warranty. So, if you see clouding or encounter another problem with the seal of your glass, first obtain the serial number from your skylight. Then, contact our customer service team at 1-800-888-3589. We'll be happy to help you determine if your warranty is still in effect and guide you through the next steps to correct your issue.