Many wall/roof systems have more than one air barrier - what exactly defines what is inside the weather/air barrier - the most interior air barrier?
a minimum perm rating? Also, if an adhesive is used to adhere a membrane barrier - then that adhesive is exposed to the interior and should be included.

also - I just want to confirm that roofing adhesives are definitely excluded from this credit as per addenda posting 11/3/10. I'm looking at submittals now from Carlisle that advertise their low VOC adhesive primers (250 g/L) and lap sealants (348 g/L) for EPDM single ply roofing membranes along with other possible LEED attributes.