GRP roof leaking... Top coat not applied yet

You need to cut out the white sections as that is a sign of contamination of moisture, putting more resin on top may or may not work its a risk. I would personally cut them out then sand the area, then apply new matting and resin. The roof shouldn’t leak if top coat isn’t applied, top coat is there to give the roof a nice finish and protect from suns UV rays bud give a bit more fire protection. Don’t put the top coat on really thick it will crack, I’d advice watching the official YouTube channel of the Cure It manufacturers they do a lot of master class videos going into great depth and how to fix common issues like this one. This will get you up to speed of how it’s done and to keep within manufacturers recommendations for there guarantees. Regards Frankie

Let it cure my guess is he’s not used winter hardner and it was too cold sand it Back and put more hardner in and top coat over that

White patches are dues to moisture- either wet decking boards or rain. You will need to cut these out and apply new matting. The topcoat should be applied within 24hrs. If not sand down and acetone the roof, then topcoat immediately. A roof that has been laminated but not topcoated would not leak. KR Drew