[911SauCy]

I just had my attic insulated but the differences in climate from CT to Orange County make all the difference in response.

My house was built in '58, had R-4 equivalent existing, and 18"+ tall ice dams because the soffits weren't vented and we were heating the attic.

For a 1200sqft job, they had 3 guys work all day building 600sf of flooring, a retaining barrier around said flooring to hold the insulation (R-38) back, installed the proper vents in the soffits, and made some awesome foam attic stair entry thing with removable door.... I laid out $3100, but we got an "energy tax credit" for $1/sf, so total outlay after credit was $1900.

Between this and a home energy audit, my investment will pay for itself in 17 months. The day the job was complete our upstairs was remarkably warmer and the thermostat was turned down 4 degrees as the house managed to remain at 66 without continual help from the furnace.

Mind you, this is in an opposite environment...

Perhaps the HeatBLOC stuff is your better bet altogether?

FWIW, R-38 is standard building code here in CT, so not really overkill.