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Community and Q&A

Seeking Opinions on this Roof Assembly

ronzmac | Posted in Energy Efficiency and Durability on


I’m building a new house and looking to do unvented attics for the main house and vented attics for the garages/back porch areas.

I’m currently thinking about the roof assembly and what insulation to use in the attic.  It seems like the goals would be to implement:  radiant barrier, rigid foam insulation on the exterior, and airtightness, & good weather proofing.

After doing some reading here and reviewing some products, I’m wondering if something like this makes sense.  I haven’t priced out anything, still in the early stages, but curious to see what thoughts you all have before I get too far into this:

I’m in Climate Zone 2.  Houston, TX.

– open cell foam in rafters
– decking (Huber Zip sheathing 5/8″)
– Insulation/Radiant Barrier (Atlas ACFoam CrossVent).  Would this go directly on top of the zip?   Sounds like you can add a radiant barrier to the underside of the OSB facing the air gap.
-finally, the roofing products.   thinking about just shingles.

Looking to hear your thoughts.   Thanks

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  1. GBA Editor
    Kiley Jacques | | #1

    I’m going to give your question a bump. You didn’t say if you are planning a cathedral ceiling or not but Martin Holladay posted an article last week that might interest you. Five Cathedral Ceilings That Work.

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