We had a leaking roof in our first fiberglass rv because we mounted something in the ceiling forgot what it was maybe a lamp.
How to fix a leaking fiberglass roof.
Remove any loose pieces of fiberglass clinging to the hole.
Fiberglass roof structures can become cracked and water may run in through the cracks.
Run water over the low side of the penetration for several minutes while the helper watches for any water droplets.
They can also have holes put through them which is a more obvious roof leak to fix.
Begin soaking low on the roof just above where the leak is visible inside the house.
Climb a ladder and inspect the roof looking for any damage or cracks in the roof.
Position a ladder so that the hole in the roof is within easy reach.
Clean the fiberglass with household cleaner and paper towels.
This brand new grp restoration coating is a super strong and straightforward one coat product for grp and fibreglass roofs with minimal preparation and no primer needed.
Use enough water to mimic heavy rains.