air sealing

[billconner]

I may be getting to far into the weeds but am trying to do a good job air sealing this added roo - livable space. Putting 1x6 t&g prefinished ceiling. Plan to put 6 mil poly under (over?) t&g (and 20" of cellulose above that). Was wondering about the penetrations - 18 guage beads - from blind nailing t&g, and whether worth it to put a butyl tape on the ceiling joists. It would have the side benefit of holding the poly in place while installing ceiling.

Too far?

 

[Zeke]

Given the 'benefit' I like it. You could do the same with drywall cardboard furring strips. I assume you staple this to the bottom of the joist. So, more penetrations. Still like the idea of holding the poly tight.

 

[billconner]

Do you think - like I do - that the butyl tape will seal around the nail holes? It would seem the butyl would seal like ice and water shield.

But I really like the possibility it will temporarily hold the poly. I was dreading the idea of fighting with that over my head.