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Fluffy stuff near the roof deck question (again)

Sam Einsohn | Posted in Energy Efficiency and Durability on

I know this is a topic/question asked MANY times but I must ask again to clarify. As a starting point I am in Climate Zone 1 (Hot Humid Hurricane Country).

Would it be dangerous or against international code to:

1. Tightly adhere a vapor open and air tight sheet like solitex mento against 2×4 rafters in a vented attic

2. Extend every 5 rafters or so with 2×6 ,8, or 10s to create depth

3. Tightly adhere insulweb or some other netting over the new 2 X’s and then blow in fluffy stuff?

My hypothesis is that 3.5” of air space at the roof deck is more than enough to allow drying. The vapor permeability of mento causes no moisture trapping by allowing drying in both directions. If adhered continuously, the Mento would create an air tight attic below. And it would drastically reduce thermal bridging. 

Thanks so much for you Help  


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