Its not normally your smooth gel coated fibreglass on the roof, just the rough finish type. I don’t think you will get any vinyl to stick to it well – if at all. Also its usually just a thin and fairly flexible sheet – you couldn’t stand on it.
If it does have a gelcoat finish then regular polymeric will be fine.
Please note:
This action will also remove this member from your connections and send a report to the site admin.
Please allow a few minutes for this process to complete.