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Help with Air Barrier Continuity

mpsterner | Posted in Energy Efficiency and Durability on

Building a house currently. Original design had second floor i-joists with a rim board that would be detailed with Tremco beads (at top plate, rim bottom, rim top to subfloor) to transfer air barrier from the main floor to the second. 

Due to sourcing, I had to switch to open web trusses. Maintaining continuity of my interior air barrier became very difficult with the open web trusses so I’ve doubled up and have an air barrier (Intello) on the inside and will spray foam through the rim joist to connect the main and second floor, however, I added a second barrier at my plywood just since I didn’t feel that was adequate. 

I am wondering, how do I transfer my air barrier from the exterior sheathing plywood to the subfloor to then continue under the roof trusses with my interior air barrier? 

The red dots are existing Tremco beads. 

My thought it that this is as simple as a healthy tremco bead against the bottom plate as shown? Is that enough to effectively transfer the air barrier to the subfloor (which is sealed in between the sheets all the way to the inside)? 

Then, same question for the areas with no second floor and just roof trusses? I’ve attached a picture of that as well. Can I just apply a bead of tremco against the top plates to transfer the air barrier from the sheathing that runs all the way up the raised heel on in to the inside ceiling? 

Yes, I have seen the articles with plywood top plate caps for helping with this. It is specifically tricky with the plywood running past the seam all the way up the raised heel. 

Thank you!

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