I have a 225 year old post and beam cape. I intend to replace the roof, but I have very little ventilation. The second floor gets extremely hot and it clearly takes it's toll on the shingles. I have an idea to build on top of the existing roof with vertical strapping every 12" with a sheathing on top, essentially allowing an airspace between the old roof and new roof. I would them utilize a ridge vent open only on the new roof to ventilate this all the way from the soffit, which would be open 1" or so due the the space created by the old roof-strapping-new roof.
Can anyone give me feedback about why this will or will not work?
Should I strip off the existing shingles for weight considerations?
I am in a very snowy climate.
