Back in the day I spent a year working for the now defunct Mac Truss Company in McMinnville, Oregon. Not long after I began working with them, they decided to relocate their manufacturing facilities across town to an old machine shop. All was fine and good with the move, until the fall rains began.
The machine shop happened to have fiberglass (FRP) skylights, which had yellowed so badly they let in less light than the adjacent steel panels. One thing they DID let in – was the weather. Not only had the FRP panels turned color, they had also become brittle and cracked. It was bad enough working in a fairly dark building, even worse when the just above freezing rains came in!
For the most part, pole building suppliers and builders have recognized the inherent challenges of trying to use light panels in roofs – very rarely does one see them installed in new buildings. Which is good, as neither FRP, polycarbonate or acrylic panels are designed to withstand shear loading (weight of anything on the roof – like ice and snow) so their use not only weakens the roof diaphragm, it also creates a future failure. A failure – in my humble opinion – being when they fracture around the fasteners due to loads they were not intended to carry and begin to leak!
Another long, hot summer has ended and people with older buildings with failed skylights are beginning to look for solutions to their building’s problems. Hardly a day goes by, which does not include an email from someone trying to find replacement panels for their old fiberglass skylights. Almost always these requests are for some panel configuration which has not been used as common practice for years.
In the event you are one of these building owners, my best recommendation is to take the photographs of your panels (clearly showing the panel profile) to the contractor desk at your nearest The Home Depot® or Lowes®. If the profile is available, either should be able to find a suitable replacement.
For more reading on skylight panels: https://www.hansenpolebuildings.com/blog/2012/01/skylights/ and https://www.hansenpolebuildings.com/blog/2014/02/acrylic/