I got prices for spray foam and batt insulation. Very expensive to go
with spray foam. For a garage that is 30' wide and 25' deep and 14'
high I got a price of $1100 plus tax, plus costs for vapour barrier
afterwards. For batt insulation $700 and that's vapour barrier
included ! In short it's twice the amount for spray foam.
Huge cost difference
Yes, but depending on things like how well the batts are installed and how
well the structure is sealed, the spray foam may be the better way to go and
result in lower heating/cooling bills. I will be using Corbond for the roof
deck in my attic and new shop.
On my place, the installation contractor cut the foam down to be even with
the studs/joists with whatever knife-like objects they had on hand (one guy
used a machete). The "roughness" was quite fine-grained -- much as if you
had cut a piece of styrofoam with a slightly dull knife.
sounds cheap to me! How much surface area did they spray?
I had a sunroom ceiling sprayed, 2x6 construction fully filled, 8x20
feet of ceiling plus some knee walls cost me $2500! Things in my area
tend to be double the cost of many other areas.
Cost will be dependant on board footage of foam. For example, I
probably ended up with about 100 cubic feet which is 1200 board feet.
Materials cost alone if you were to buy your own 2-part polyurethane
would be about $1000.
I'd never go back to fiberglass unless absolutely necessary. It
provides minimal air barrier, loses it's R value in cold weather and is
worthless if it gets damp. A good dense polyurethane will provide
maximal R value in all conditions, complete infiltration sealing and
water/vapor resistance if thick enough (>~1").
Sounds like a standalone garage. Probably not worth it, unless you live in
it for any great length of time per day. Whichever you go with, be sure the
insulation does not hinder or block air entry from exterior vents to the
attic area. This goes a long way in cooling the garage in the summer
Prices I've seen advertised were $1.60 sq.ft for a 1" flash coat (spray
foam) with R-19 batt, and $2.25 sq.ft for spray foam. (very generalized,
varies widely by local and mfgr.) In comparison, fiberglass batts are
around $0.70 sq.ft. installed. For a garage go with the least expensive as
the leakage around the overhead door is the main problem.
HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.