Air gap or no air gap?

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Air gap or no air gap?

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Both sound great. Have you looked at samples from both?

If you were in a climate that got hotter, I would lean more towards #2 in that comparison, but that's not really an issue with Seattle.

Eric Novotny
2019-05-20 18:45:51.488800

We're looking at two metal roof replacement bids. They have different install methods so I'm feeling a little overwhelmed trying to decide. I'm leaning towards Company #1 mainly because they are highly recommended, including from a few personal sources.

Weather: Seattle, climate zone 4C.

Company 1: no air gap. 1/2" CDX plywood over entire roof deck. high temperature peel and stick self-adhering membrane on entire roof and all penetrations. 4" poly-ISO insulation, between two layers of plywood to increase r-value and help regulate heat transfer.

Company 2: with air gap. The insulation will be 5.2" (GAF ENERGY GUARD ISO 5.2" R-30). 1/2" CDX plywood elevated on 2x4 furring strips installed over top of new insulation to provide continuous breathing gap from gutter edge to ridge. Eave intake will be screened behind new vertical fascia.

other notes: both companies will tear the existing roofing material off. both are recommending the same exact roof: NuRay Series 2000 (we have a low slope).

our main goals are to retain heat in the winter (we don't have insulation currently, and no attic). also hopefully to reduce some noise, particularly when crows have a dance party on our roof.

tl;dr will a no-air-gap method be a good plan? like I said, this company comes highly recommended.

Bonnie Fink
2019-05-20 18:39:37.873132