Airtight drywall: Why seal double top plates?
I’m trying to understand the airtight drywall approach and why it is important to seal across double top plates. If the sheetrock itself is air tight. If the corners and joints of the sheet rock are taped and mudded to make them air tight. If the electrical boxes are all sealed to the sheetrock and wire penetrations to the box are sealed. If the sheetrock is sealed to the subfloor. Why is it important to seal the gap between the double studded top plate? The gap in the top plate is behind the air barrier?
Here is the advice I see about air tight dry wall, I’m just trying to understand the logic.
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