I am converting my "A" frame attic into a living space. The joists stick out 5" from the roof and are 22" apart. It's an old house and measurements change give or take a half inch from joist to joist. Even though there is no ridge vent there are roof louvers about 3 ' from the peak. I can only find the pink insulation in 15" widths so it is too narrow for a perfect fit between them. I figure the 3 and 1/2 inch thickness will be okay and allow space for air to flow. Not sure if it should be faced or not ( I live in PA if that helps). The roof goes right to the edge of the house so there are no soffit vents. I attached a very crude sketch with two of the ideas I have for insulation. The third would be combining both and insulate both the roof and walls. What type of insulation should I use (the pink stuff, blue styrofoam, etc) and how, plus will the venting be enough or should I ad an exhaust fan of some type? The roof is 32' X 28". I have 6 of the roof louvers to vent it now (2 on each side of my "T" shaped attic). I also though maybye gable vents might work even better since my house is old and dips in the middle a little allowing for more hot air flow towards the ends of the roof. I'm sure they have to be cheaper than ridge venting the whole thing. Thank you for any help or ideas on any of these issues.

It looks like you are going to make living space in the attic?

If so, you need to find 22 1/2" insulation,preferably faced.something you can staple to the rafters(3 1/2" should do) Otherwise, a solid insulation board(which I used for my barn/home,which has a R7 per inch, it is called polyisocyanurate, and can be found through some suppliers and with that R value is by far the best I have used for the money.

Insulating the floor spaces can be done with blown insulation, 12-16 inches or more if you can, without too much undue run over, blown in is easy and efficient.

Venting is adequate, as you stated, you already have vents in the 32 foot ridge? That's plenty. Gable vents are not necessary, but if you want, install,I don't see them as needed because you have enough with the others.

Hope this helps,

Ken

Answered all my questions and has experience with his recommendations

Try to add some soffit vents and make sure that there is airspace between the roof deck and insulation. If you don't ensure adequate insulation that space will be an oven.

I live in a frame with 26 ft ceiling at the peak and the walls leading up to the peak also serve as my interior walls. The attic under the peak also is floored and I can stand erect in this area. Very little insulation in the attic and a light coating in the exterior walls. Whatever they used 40 yrs ago when home was built. Getting ready to replace the original roof (yes I did say 40 yrs old I only have vents in the peaks on both sides which is also screened to allow ventilation. First question is will I need a ridge vent? Second question is how would I insulate the walls(ceilings) going up to the peak as they act as interior walls. Would I insulate them and if so will my home still breath? Or should I just do the attic? Thank you in advance for your response.