[ASKNACHI]This question was posted on AskNACHI.org by Terry Lowe (from Penticton BC). [/ASKNACHI]Installation of Pot lights. Vapour barrier etc How to???
Hopefully, this might help you a bit.
http://www.pct.edu/wtc/pdf/BB0502-Air-Leakage-in-Recessed-Lights.pdf
Marcel 