How to add insulation to existing roof – Ice dam prevention
I have a 54 year old Cape style home in Nerw England. Plaster ceilings run along the base of the roof rafters (2×6 rafters). No soffits – have Hicks vent drip edge & Full ridge vent. Need to re-roof, want to add insulation, build out vented soffit system,- by adding rafter tails, extend the rakes out, Ice & water 6 feet from edge & valleys then re-roof.
One option presented is to remove existing roof , deck & what ever insulation might be there, then spray in foam, add 2 to 4 inches of rigid insulation, new roof deck & then re-roof. Second would be blow in cellulose below existing deck, then add rigid foam , new deck etc.
third is just add rigid on top of existing deck, add new deck & re-roof.
How do you get a cool deck using the rigid – Do we need to add 2 x 2 screwed through rigid to the rafters?
Any thoughts / feedback greatly appreciated
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