Began with a 14 x 14 template made from a pizza box. Inside the van, we identified where we wanted to place the fan and drilled 4 pilot holes from so that we could finish the guides on the roof and tape it off. Also added a catch bag inside to collect metal particles.
Utilizing a jigsaw with a sheet metal blade, the hole was cut, followed by a few minutes of trimming to fit the bracket.
Added several layers of butyl tape to fill the valleys and create a level seal to place the bracket. Screwed in the bracket and sealed the everything with self leveling sealant (Lap Sealant)
Installed the fan fixture and screwed in the vent top. Added a basic frame inside that the bracket is screwed into. This is to help strengthen and support the install.