Can we put Rockwool up against the roof deck?
We have a 100+ year old Dutch colonial house in Climate Zone 4 that we’re renovating. We have put R30 Rockwool batts in the attic flooring (without Membrain underneath) that is obviously not an optimal amount and the CAC unit and ducts are above the flooring in unconditioned space. We’d like to install Rockwool batts in between the rafters, held in place with Certainteed Membrain, but do we need to install baffles for an airspace?
There is only an attic fan now for ventilation (no soffit or roof vents). The roof (which will be replaced within a few years with vapor permeable peal and stick and shingles) is asphalt shingles, with tar paper underneath over the plywood. The plywood is on 1x2s affixed to the rafters (see pics). And yes, we will be moving the flex duct out of the rafters and perhaps adding more insulation to them.
So can we install the batts up against the rafters? Should we close off the attic fan? Install an ERV or dehumidifier?
Thanks to all for your assistance.
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