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TOPIC: Insulation Concerns

Felt and Insulation questions for re-roof

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First thanks for doing this, so glad i found this site. I currently have a composition shingled roof that I am having re-roofed due to hail damage. I live just outside of Austin (hot & sunny summers, been over 100 several days this year), the house has an attic, has a vaulted ceiling on the west side of the house, and has soffit vents. It has was I understand as a hip roof, so a ridge vent is out, but I have one power ventilator (kicks on at 125 degrees and has run a lot this summer it was over 107 in there last weekend at 11 am) and am having them add another. The attic is well insulated and I am planning on adding soffit chutes and the reflective sheeting to the rafters. I am upgrading my roof to Galvalume. The roofer is leaving the shingles on, laying 1x4s 2' apart and then laying the Galvalume. Here are my questions- I received a couple options, but this one doesn't appear to include felt, should it? The other options list 15# instead of 30# felt, they said this is their standard, is this ok? Lastly, my dad had this same roof put on, but said he wished he had the insulation board put in b/w the 1x4s, the roofer is not sure that is is necessary, what do you think? Thank you for all your help and any other suggestions are greatly appreciated.
Jennifer Beale

7/16/2009
If your attic is well insulated and you are adding more ventilation, then any insulation above the decking is unnecessary and with your old shingles still on, the insulation board achieves no purpose. I have always felt that a shingle roof in decent condition makes a good enough vapor barrier and condensation barrier that felt is not needed. If you do use felt, use 30 lb., it is the minimum that most manufacturers specify under metal.
Wade Matthews
Roof it with metal-Roof it to last

7/16/2009