Assuming your current attic insulation is made from fiberglass and has a value of r 13 you d have to add roughly 10 inches of additional fiberglass to hit r 38.
Cellulose vs fiberglass attic.
Compared to fiberglass cellulose is a superb air blocker.
Since cellulose is blown in it fills all the gaps crevices nooks and crannies in your attic unlike batts that can leave gaps.
Both cellulose and fiberglass insulation have their pros and cons but i feel that cellulose is the better bet overall.
Air moving through a vented attic deposits dirt and dust into fiberglass batts.
Rather than trying to meticulously lay fiberglass insulation over the attic homeowners and builders can simply blow cellulose insulation throughout the attic.
When comparing blown in insulation both fiberglass and cellulose are nearly identical in price both costing around 0 70 to 0 80 per square foot for 6 inches of insulation.
Fiberglass vs cellulose the pros and cons by comparison posted on mar 23 2017 there are many different types of insulation to use in your home s walls attic and basement but the two most types of insulation are fiberglass and cellulose.
Cellulose insulates better than fiberglass especially in very cold weather.
More comfortable and energy efficient.
So it seems to me the real debate.
Cellulose has an r value of 3 5 3 7 per inch where fiberglass has around 2 1 2 7 r per inch.
Cellulose insulation blown in wall r 3 8 r3 9.
Cellulose insulation blown in attic r 3 6 r3 7.
Unless you opt for spray foam then the insulation choices normally come down to cellulose and fibreglass.
Fiberglass batts however are less expensive costing on average 0 30 to 0 40 a square foot for 6 inches of insulation.
This is called wind washing.
Both fiberglass and cellulose insulation can be installed to completely fill the space inside of wall floor or ceiling cavity.
The two main least expensive and most commonly used residential insulation materials is cellulose and fibreglass.
Blown cellulose is typically the preferred choice of insulation for attics.
Higher r value per inch.
Cellulose retains more of its r value through a wider range of temperatures compared to fiberglass.
Blown in cellulose homeowner benefits.
Cellulose wins last update.
Or 7 inches of cellulose.