I am going to build a little 16 x 20 garage that will attach to the walkout level of my place and I am planning on putting a gambrel roof on it and using the attic as another room. The roof will be 2 x 6 rafters and I was planning on using batt insulation and then drywalling. I can either sheet in the whole ceiling to make it like a cathedral or leave a little space at the ridge for ventilation. I have been reading up on this and have heard conflicting opinions on the issue, no vapor barrier, vapor barrier, baffles, etc. Has anyone used a gambrel attic in this way and have any opinions?
I have a similar application. My garage is a two storey gambrel roof building that I'd like to finish. I'm not 100% sure how to go about doing the second floor ventilation. Currently there is a ridge vent, and soffit vents that run the entire length of building. The trusses (2x6) that are installed now would leave room for an air space in the peak of the roof, and at the change in pitch of the roof. How do I ventilate/insulate this??
I'm not sure of the term for it, but should I use the stryofoam soffit ventways to get from the soffit vents to the first air space, then another one from there to the air space in the peak? As far as I can tell, any insulation would completely fill the space between the outer and inner walls of the roof, except for the two spaces I described above.
Also, do I need vapour barrier, and if so, do I install it on the entire roof?