I used to once think fiberglass as a virtually indestructible material, but experience has shown me that it is not. It ages and weathers. Keep in mind that it is basically a type of plastic holding the glass fibers together and covering them. The sun can be hard on almost all plastics. A coated metal will hold up better. (I don't know about Lexan.)

https://www.alunotec.com/Louvered-Pergola-Roof-Kits-pd6926535.html

I'm curious if the previous commenters have built fiberglass pergolas. We've used several manufacturers for fiberglass pergolas. They're painted at the factory (typically offering Sherwin Williams or Benjamin Moore colors) and, like any other painted surface, will need occasional love. I've never seen fiberglass offered *not* painted. Patricia, can you please explain to me how a painted material turns yellow in the sun?

Fiberglass has some great properties for a pergola application. You can get clear spans (distance between posts) that you can't get from wood. Also because all the members are hollow, it's easy to hide wiring for lights and speakers.

Being that you're in SoCal I'd look into how fiberglass pergolas work with your seismic requirements. Typically the way a fiberglass pergola is built is there's a threaded rod that is anchored to the footer and extends through the post, The beam slides over the rod, and a nut is tightened down, holding everything very solidly via compression. As I'm not an engineer, I don't know if that's good or bad with regard to earthquakes, but I worry that it's so rigid you'd have a failure point.

You may also consider a composite pergola. There's a company here in VA that builds pergolas that are hollow aluminum beams clad with composite lumber. You can also get nice long spans with these, and you can also use the hollow cores as wire chases. This is them, super nice folks: https://www.structureworksfab.com/ They also offer fiberglass so they'd be a good resource for the pros and cons of each.

Real Wood in SoCal due to the sun and heat. An aluminum patio cover would burn your skin, and fiberglass would not last. I think some of these people live in “canada” and have only seen the sun when they visit CA... I used rough cut wood, it will have to be painted every 5-7 years, to keep it looking nice.

I lived in San Diego for a year and a half, and Phoenix for 6 years, so that's almost accurate.

Thank you everyone for you comments. And for other material suggestions and sources. I'll look into those. We are coastal SoCal. Termites are the biggest annoyance. And Revolutionary Gardens, thank you for bringing up the point about earthquake considerations.

Really ever been to Canada I live where the summers can be 40C + for long periods of time and fiberglass gets brittle and yellows . BTW that is 100 degrees plus we don’t all live in igloos either I happen to see the sun most of the year have an outdoor pool used from May to end of Sept.

Sorry to hijack the thread #BeverlyFLADeziner, is that company Alunotec one you have used it know someone who has? I came across them but couldn't find any