insulating my attic - two questions

I have a 1922 house in NJ that has no insulation. I have a couple of questions about the finished attic.

First, about the ceiling joists on the ceiling of the top most floor; I dont want to blow in loose fill insulation, I want to put in batt or kraft faced between the joists. Question; does it make sense to put in such insulatin so that it sticks over the top of the joists (is deeper than the joists)?

Secondly, being sensitive to vapor and heat loss, what would be the best way to insulate this attic. I have created a webpage to illustrate. The top part of the attic will be vented in summer and winter, the horizontal walls will be insulated, Question; do I simply insulate the diagonal sections or do I vent them?

cut and paste this into another browser window to see:

www.yogamandali.com/archived/house.htmhttp://www.yogamandali.com/archived/house.htm

 

dvarga, read this thread. The woman has the same scenario as you: http://forum.doityourself.com/showth...hreadid=151650

In your diagram question #2, you definately want to insulate this area but you need to maintain an air gap between the insulation and the underside of the roof. Thats where the foam baffles come into play.
Also, about insulating between your ceiling joists. You should lay kraft faced insulation (paper facing towards living space) that will be even with the joists, then you can roll a second layer of unfaced insulation perpendicular to the joists causing the top layer to criss cross sealing any gaps.

 

Thanks dregg, very helpful...