Hi All,
I’m working on a retrofit of a large 1980s passive-style A-frame in seaside Nova Scotia (~ 5,000 sq ft). Previous siding work (on gable walls) was done poorly– new cedar shingles and metal cladding were installed over the existing siding with extremely little attention to window or door flashing.
The clients now want to remove the walls and reconstruct the outside appropriately with a rainscreen.
Current wall assembly seems:
The doors and windows are currently set at the plane of the outside foam.
If we strip everything back to the plywood, I’m thinking about two approaches:
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Install ZIP-R sheathing to include constant outside insulation and a taped WRB in one step.
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Set up a different WRB and outside insulation over the existing sheathing, followed by a rainscreen.
My other concern worries the existing doors and windows. Ideally I would leave them in location to prevent troubling interior trim, but that would require integrating the new WRB and insulation around the existing flanged units.
Some builders have recommended treating them as “innie” windows– cutting the old foam back to the flange and connecting the brand-new WRB into the opening, then constructing extension bucks for the brand-new siding aircraft.
My concerns:
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For this kind of retrofit, would ZIP-R be a great option or would a different WRB + outside insulation assembly be more robust?
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Is it sensible to incorporate existing flanged windows into a new exterior insulation/WRB assembly, or is eliminating and reinstalling them the better long-lasting approach? My feeling is no and I must be pulling the windows and doors.
My top priorities are resilience and good water management in a damp coastal climate.
Thanks for your thoughts and time!