Inverted Attic Soffit for HVAC Ducts Question
Had to put ductwork in attic of new construction. Plan is for inverted soffit to bring them inside thermal envelope but couldn’t use plenum trusses. Builder wants to box in all ductwork in attic with zip boards and taped seams. Then pile
insulation on top of boxed in ducts. Will this work?
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That will work. Unless you're using off-cuts to make the soffit, consider using drywall, plywood or OSB. Lots of substrates can be easily taped. The Zip WRB doesn't do you any good in the attic, so why pay for it? But you may be less, uh, cost-conscious than I am.