slant roof insulation
 

I have an old home built in the 1890's. When it snows the snow melts off the roof and the icicles form on the eaves.

This has 4ft kneewalls and a 6ft slant ceiling then it is a flat ceiling. I want to gut out one room at a time and insulate the kneewalls and the slanted ceiling. I would like to fill the ceiling cavity with insulation. There is no means to ventilate so I want to install what they calll a hot roof insulation. My question is what r value do they recommend for this system to work?

Harly