Building a log cabin. Have installed a steel roof on 1x4 stapping which is on top of the 2x10 rafters.
How would one finish the under side - insulation etc. The ceiling will be 1x6 T&G pine directly on the underside of the rafters.
Should I spray foam directly to the roofing- what thickness?
Or should I create a channel from eave to ridge for ventilation and then install fiberglas insulation?
Where should a vapour barrier be installed?

This cabin will be mainly used in summer and fall with a few winter weekends.

Any help would be appreciated.
Thanks Jerry

foam is best, but expensive.

The key is keeping moisture from contacting a condensing cooler surface. Either super insulation to isolate cool surfaces, venting moisture out, or using perfect vapour barriers to keep interior moist air from escapintg to contact the metal - or a combination of all three.

Excellence is its own reward!