I am in the process of finishing the living quarters in my Kiefer XLA trailer. It has a vent that cranks open, but I want to put a Fantastic Fan in. I removed the million screws the manufacture put in plus the layer of silicone...but it still will not budge. I suppose there is a layer of silicone between the vent and roof. I called Camping World...as they install..they said all they would do is take a razor and keep cutting away on the silicone..not much visible though as it mainly is the vent itself adhering to the roof. The service dept said they get up on the roof to do this...I thought that fiberglass roofs are not strong enough to walk on? The trailer is 5 y/o and has been sitting out in Chicago area winters. Any info on this would be most appreciated. Thanks.

Nancy

Did you remove the vanity or glamor ring from the inside ceiling?

Fiberglass roofs are strong enough - but treat them like the rafters in an attic - that is, keep your weight on a roof beam/support and keep to hands & knees (to spread out your weight). 

The RV technician crawled around on the roof of my 1988 Circle J trailer when it was 14 years old - and it's sat out in the Michigan weather probably its entire life.