Spray Applied Air Sealing Other Than Spray Foam? – GreenBuildingAdvisor

I’ve had lots of questions recently.  We are nearing the end of our framing.  I’ve been working with the framers on some of the details to make a continuous air barrier path from the exterior sheathing to the inside of the ceiling.  Because we are using parallel chord trusses and a girder beam, our gable walls are built all the way to the roof.  I talked to the framer about taping the sheathing to the top plate so I can connect to it on the inside.   Unfortunately, when I got on site today, I realized it got missed and they have already started sheeting the roof.  I’m trying to figure out what to do to connect the exterior sheathing to the inside now. 

My thoughts are to spray the underside of the top plate where it meets the interior side of the plywood.  I’m wondering what options there are for this if I can avoid spray foam?  475 has the Aerofixx kit, but it’s $700 and seems overkill for this smallish job. 

Any other options or thoughts on how to seal up this joint?  I’m hoping on the other end of the house we get it right, he hasn’t done the trusses or  roof deck yet.