[VAC] Fantastic-Fan Installation Question

[Safari1972@xxxxxxx]

Greetings,
I am installing a Fantastic-Fan and question the installation instructions.   
The company says to put a foam seal (that they provide) between the fan 
housing and the outside of the skin of the roof, then screw to roof and then 
apply 1/4" beed of silicone on the outside of the housing where it meets the 
roof.   
This seems fine but it seems to me that given the rivets on the roof that not 
using the foam but using Vulkem both between the roof and the plastic housing 
and letting the surplus squize out after screwing down, then applying a bead 
of Vulkem on the outside would be best.
Anyone have any experience or suggestions?  I hate to not install per the 
company instructions but for this application it seems best.......

Thanks,
John Semon
San Luis Obispo, Ca
safari1972@aol.com