Insulate Garage Ceiling cathedral

Hi

I want to insulate my garage by placing insulation in the Roof Rafters (Air space between insulation and roof shething will be provided).

My question is does building code require something (Drywall....Plywood....) be placed over the insulation.

Thanks in advance
albanello

I'm an architect and stumbled on your question by chance - no code requires you to encapsulate your insulation in a garage, moreover, the weight of the drywall may too much for your existing rafters, best to install vinyl or paper faced insulation.

afarchitect

Thank you very much for your response. I was thinking the same thing that the dry wall may be to heavy for the roof rafters.

One of the simplest solutions I can come up with is to get 4x8 sheets of 3" ridged foam insulation and just screw it to the bottom of the roof rafters, naturally the joints would be taped. What do you think of this solution? It would be very easy to do as opposed to stuffing insulation between each rafter.

Again thank you for your response and I look forward to hearing for you again.

albanello