What is better – roof vents without soffit vents or change to an unvented assembly?
I’m back after having met with the architect and asked about the soffit venting.
We’re designing a home in Southern California (hot dry / mixed dry climate) – the architect is calling for an unconditioned attic, insulation on the attic floor at the ceiling, but fire codes in this wildfire prone part of the world now ban soffit vents of any kind, effectively requiring boxed or sealed eaves. The architect has drawn in a bunch of roof vents that apparently are permitted, but it makes me wonder how effective those can actually be, if they’re halfway up the roof, and they’re not every sixteen inches.
Might we be better switching to an unvented roof assembly? We are already planning on using radiant barrier sheathing on the roof sheathing to reduce the attic temp in summer. Could we put 2 inches of poly-iso foam on the inside of the roof rafters and ditch the vents?
Most years, we get only 4-5 nights that dip below freezing. But I know that unvented roof assemblies need to be designed not to accumulate moisture that can condense.
Thanks in advance.
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