Q&A: A Forum for Green Building Experts and Beginners

Two weeks ago, We had Sealection 500 sprayed in wall cavities and under roof decking (metal roof) for our new home build. The smell seemed minor by 2 days after, then the ingition barrier - Blazelok IB4 was sprayed on entire roof deck. One week later, the smell is as bad a the day they sprayed the Blazelok IB4. Cure rate is 2-3 hrs so something seems wrong.
The chemical smell burns your eyes and nose, I can taste a metallic taste on my tongue and get dizzy after entering the home if any windows are closed.

We are building a house in Quebec province, Canada — so very cold winters and hot / sometimes humid summers. We were set on installing fiberglass windows triple / double panes according to exposure of lot (mainly southern and eastern with a little western and very little northern.)

I'm considering using rigid foam on the exterior of my roof. Cost is of course a big concern with this approach. I'm found sites online that sell recycled rigid foam. Apparently, it is often recovered from commercial buildings and shipping containers.

I read one post on the site that caution against using foam that had been degrade during freeze/thaw cycles. Are there any other issues to look out for? Have anyone tried the "recycled" approach? Is there a reputable source for material? Any lessons learned you folks could share would be greatly appreciated.

I'm getting quotes from contractors right now to insulate a small cottage with an unvented cathedral ceiling using 2x10s. I'm in zone 3C.

One contractor has suggested spraying 5.5" of open-cell foam between the rafters and calling it a day. I asked if we could just fill the entire 9.5" cavity and he said, "You achieve maximum efficiency @5.5. Any more is overkill. It will expand a couple more inches as we will not cut it but leave the excess."

Code requires R-30 for ceilings around here.

I may be wrong but doesn't more insulation mean higher R-value?