Got a quote from abig box store for insulation and of course it was expensive, but it raised some questions:
The quote was 2 parts:
1st was adding more insulation to the attic. I have about R18 now and they quoted to take it to R38 which seems like over-kill.
Price quoted was just under a dollar per sq. foot for blown in fiberglass. Seems a little higher that I'd like.
2nd part of the quote was for a product called HEATBLOC ULTRA.
HeatBLOC - High-Efficiency Attic Heat Barrier
it's an aluminized paint they spray on the underside of the roof and it is supposed to refract the heat back up through the roof to keep the attic cooler.
High pressure sales techniques, as if it is a gotta-do thing.
I was instantly skeptical.
Questions I brought up: does it cook the roofing materials? They say no.
Does it trap moisture in the roof reducing the life? They said no.
If i have plenty of attic insulation and proper attic ventillation, does that silver stuff really make any significant difference? crickets chirping.
Price quoted was about $1.25 sq. foot applied (spray painted).
I checked e-bay, the stuff costs $60 per gallon and covers 400 to 500 sq feet per gallon.
That means that about 6 gallons would easily do the job at my house.
The manufacturer website says 1 person can cover 1000 sq feet an hour.
Assuming they work in pairs, I can't see more than 4 man-hours max, plus $360 worth of material.
But they quoted 4 times that much.
Questions:
How much should it cost to take the attic insulation from R18 to R38 (good attic access, 4-12 pitch).
How much blown in insulation do I really need before diminishing returns makes it over-kill (Orange county, 15 miles from ocean).
Does that painted aluminum stuff really make a difference, is it worth it, does it hurt the roof, and what should it really cost?
Tanks in advance.