What to do with Vapour Barrier in Those Dreaded Corners
One of the construction details requires the vapour barrier to be pulled out over the top of the stem wall where the weight of the stud wall will keep it in place. Blueskin will then be taped to the interior OSB and sealed to the vapour barrier using the self adhered backing and acoustical sealant. Leaving the framers to drop the wall onto the vapour barrier and having a messy corner to seal would be a bit of an inconvenience so I decided to try something to deal with the vapour barrier. I have seen builders cut a slit at the corner to ease the transition of the vapour barrier over the top of the foundation but I didn't like this solution since it would be a mess to air seal properly. I decided to try a heat gun! I heated the corner slowly. I started at the base near the concrete and move upwards and outwards from the corner knowing that the vapour barrier at the top edge would have to stretch more than the barrier at the corner. After 30 s the barrier became softer and had a slight translucence (Photo 2-1, 2-2). At this point I turned of the gun, and with my work gloves on, I used hand pressure to slowly push the vapour barrier downwards and outwards in the direction of the corner and held it in place for 10 s - 20 s to wait for it to cool down. Photo 3-1 is the final result.
It will be much easier to work with when it comes time to air seal this to the OSB air barrier on the inside of the house. Some Blueskin and acoustical sealant will make this an easy job now that it rests flat.