Another insulation question..

[feihong]

There's quite a few insulation questions lately.. maybe because we just had coldest winter in years? Anywayz, I would like to hear from anyone's feedback on the spray in polyurethane foam insulation.. it sounds quite appealing, in that it seals all the drafts, it's totally air tight and water proof, but the cost is a little bit high ($770 for 2.87m3 supply). Even at the recommended minimum thickness of 35mm, it still costs 2.5X higher than R3.0 polyester batts.

 

[AlmostBob]

from the spray foam brochure basf walltite http://www.basf.com/basf-canada/productsheets/walltite/walltite-E.pdf

* The oven aged thermal resistance is used for comparative purposes and does not yield a design value for long term thermal performance. The assigned thermal resistance from CCMC is 1.05 RSI per 25 mm or R6 per inch.​

R6 per inch at 37mm is R8.4 (use 75mm in Ca)
how much in pink batts wouild it take to get to R8.4, 2.5 layers,

it still costs 2.5X higher than R3.0 polyester batts

thats a lot of fuel not used to heat or cool the house must safe some money.
spray foam takes 1 man about 4 hours on a house at frame stage, batt installation take a crew days
batt insulation requires foil or membrane to stop condensation, which is seldom considered in costs, untill after the job is started, and it has to be taped in place.

unrelated info:
foam is great for renos on old houses,
dries structurally hard,
and stops oll the creaks and movements of loose nails​

(it gets minus 20degC here in an average winter, insulation is a big thing)