Vapor retarder/barrier in an insulated above-garage floor
CZ6A, Ottawa ON
Our build will have a bedroom that extends out above the un-insulated garage. The floor will be 14″ deep I joists and will be dense packed with cellulose (R50-ish). I’m planning to use Intello on the interior walls as a vapor retarder.
Question: What should I do for a vapor retarder/barrier above the garage?
Do I use a vapor retarder on top (between the floor sheething and joists), underneath (between the joists and the garage ceiling drywall), or is a totally different approach necessary? Should I be using a vapor barrier instead, like 6 mil poly?
I’m detailing the framing in this area and want to have a clearly defined path laid out for my vapor and air control layers.
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