Insulating skylight frame
So we got our shingles replaced and took the opportunity to do a chainsaw retrofit and added 2 layers of 2″ EPS with Neopor (Terrafoam Platinum) which we tied in to the existing 2″ EPS on the exterior of the wall sheathing I installed two years ago. Also replaced was the enormous plexiglass dome skylight in our upstairs ensuite bathroom. I didn’t think how we were going to insulate it at the time of installation however and am just trying to figure that out now. We just had our first hard frost and the heat loss from the skylight frame is quite evident on account of there being no frost a good 4″ all around said skylight.
So I was thinking of gluing some of the leftover 2″ EPS to the inside of the frame and covering that with either drywall (a little wary of this due to condensation on the skylight, it being a bathroom and all.) or wide cedar trim. Not sure how to cover the end of the EPS where it would be butted up to the skylight glass, Thick black vapour barrier glued on had crossed my mind. Attached pics show general size, roof cross section on outside of frame, and example piece of EPS. So which would you do and how would you go about it?