What’s the best all around roofing/insulation solution for Zone 5?
Hello to the community. I am in northern Nevada zone 5. This is an arid valley with normally low humidity but it can get some really high winds… upwards of 80 mph. The house I just bought was built in the 70’s. There is about 6 inches of blown insulation in the attic but none under the roof sheathing. I do plan on bringing the attic insulation up to at least R40. The attic has two small gable vents but zero soffit vents. The roof is completely failed cedar shakes with a lot of exposed sheathing throughout. Obviously I plan on re-roofing asap with winter coming on but this is also an opportunity to go green on the most critical part of the house – the Roof.
So what is the recommended roofing solution for this climate and circumstance???
1. I plan on using the new asphalt shingles with the reflective material. Owens Corning Duration Premier Cool shingles are one such product.
2. Additionally should I use:
2a. Sheet rigid foam (polyiso or EPS [or a combo]) under the shingles? If so how much?
2aa. Would I need an air gap?
2ab. Would a roof liner or membrane (in addition to the roofing felt) add anything of value?
2b. Insulation between the rafters under the sheathing? If so How much?
2c. or both??? if so, How much and what composition.
I am sure lots of folks are facing some combination of problems of a similar nature so I hope this inquiry sparks a lively discussion.
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