Venting cross gabled Cape Cods?
I have recently re-worked my zone 4a (central MD) Cape Cod’s attic insulation. Am now shifting focus to attic ventilation, which is 1) currently lacking and 2) complicated (see attached figure).
The insulation project involved:
– plugged floor joists under kneewall using cut-and-cobbled 2″ XPS blocks
– air sealed everywhere
– installed site-built XPS baffles at top plate/soffit areas
– placed R30 rock wool in floor joists with another perpendicular layer above (R60 total)
– put R15 in knee wall cavities, then secured with 4″ XPS foam (R35 total)
This project has hopefully improved the 4,640 cfm50 measured prior to this work. However, am now concerned the lack of ventilation may come back to haunt me.
My question – what’s the best way to vent my attic area, which includes intersecting gable roof lines (the attached figure’s blue and yellow shaded areas) and a porch overhang (orange)? We currently have 2 small soffit vents and a gable vent in the attic, with 2 additional gable vents above the living space.
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