Ceiling Service Cavity and Mositure
Hello my name is Mark and I live in eastern Tennessee (4A). I will be building a new home soon and I’m working through a few last details. One concern that I have is that I will have a continuous air barrier on the exterior sheathing (zip sheathing) and will build a service cavity for the ceiling, which will be 2×8’s in most rooms, with zip installed above that, with all seams taped including the top corner of the walls as it transitions from the wall to the attic floor/ top of service cavity. My concern is that of permeability of the zip in the ceiling service cavity in my humid climate and wether plywood, with its somewhat more forgiving management of moisture, would be a better choice?
Also, would it be worth the effort to try and follow a more air tight drywall approach for any penetrations in the ceiling, such as using gasketed electrical boxes to limit any household moisture from accumulating in the cavity?
lastly, above the zip/ plywood air barrier I do plan to use blown in cellulose insulation somewhere in the tune to around r60 and I also plan to have a variable speed ducted HVAC system and balanced ventilation.
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