Solar Panels on GRP Flat Roof ?

I have a flat roof topped of with GRP.

Planning to get some additional panels to go with the main roof installation. No drama.

I was expecting free standing with ballast. But the surveyor has suggested bolting them down though the roof to the joists.

Panic mode engaged, I’m like no way. Rather not have panels on the flat if it could mess up the integrity of the flat roof.

Am worrying uncessarily?

Anyone here got panels on a flat roof without making holes and future problems.

Thanks.

I’ve got panels on a flat roof (3 degrees pitch, but close enough) but it’s corrugated steel, not grp. It mostly annoys me because there isn’t sufficient angle to allow the panels to be self cleaning. No leaks though. I put panels on because it was cheaper than insulating to prevent us roasting on hot days (it’s ona pergola)

I can’t see any benefit to fixing through the deck, only drawbacks. They should be checked for wind uplift but only to determine the appropriate level of ballasting.

My dad was an architect…. He never had anything that put a hole in a flat roof as he said it would always end badly.

That said, the ballast to hold the panels down is going to be pretty heavy I’d imagine so you may have an issue there as well.