GBA Logo horizontal Facebook LinkedIn Email Pinterest Twitter X Instagram YouTube Icon Navigation Search Icon Main Search Icon Video Play Icon Plus Icon Minus Icon Picture icon Hamburger Icon Close Icon Sorted

Community and Q&A

Inverted Attic Soffit for HVAC Ducts Question

MikeHudson | Posted in General Questions on

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?

GBA Prime

Join the leading community of building science experts

Become a GBA Prime member and get instant access to the latest developments in green building, research, and reports from the field.


  1. b_coplin | | #1

    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.

Log in or create an account to post an answer.


Recent Questions and Replies

  • |
  • |
  • |
  • |