Cellulose Vs Fiberglass Blown In Attic

In extreme situations such as the upper midwest this reduction in r value approaches 50 percent.

Cellulose vs fiberglass blown in 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. Blown fiberglass on the other hand is made up of very fine strands of glass and these tiny fibers are a carcinogen that can easily be inhaled into your lungs. Rather than trying to meticulously lay fiberglass insulation over the attic homeowners and builders can simply blow cellulose insulation throughout the attic. Cellulose insulation blown in attic r 3 6 r3 7 cellulose insulation blown in wall r 3 8 r3 9 both fiberglass and cellulose insulation can be installed to completely fill the space inside of wall floor or ceiling cavity.

This is called wind washing. Higher r value per inch. Dry blown cellulose will characteristically settle and sag in place reducing its r value. When using cellulose blown in dry insulation it requires a machine to achieve its purpose and a training session from wherever you rent the blower from.

Cellulose has an r value of 3 5 3 7 per inch where fiberglass has around 2 1 2 7 r per inch. This phenomena seems to occur as a result of thermal convection. As the temperature difference between the living space and attic increases the r value of blown fiberglass diminishes. Cellulose attic insulation read more.

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. Or 7 inches of cellulose. Air moving through a vented attic deposits dirt and dust into fiberglass batts. Loose fill or blown cellulose insulation is manufactured primarily from recycled newspapers a very benign product so it poses virtually no ongoing health risk.

Since cellulose is blown in it fills all the gaps crevices nooks and crannies in your attic unlike batts that can leave gaps. As a recycled paper product cellulose is prone to absorb moisture that can cause wood rot and mould. Loose fill blown fiberglass insulation has another slight problem. Fiberglass batts however are less expensive costing on average 0 30 to 0 40 a square foot for 6 inches of insulation.

You can get to the same place with either material. Compared to fiberglass cellulose is a superb air blocker. Fiberglass insulation is the easiest insulation product on the market to install and if installed correctly the most effective product on the market for home attic insulation. Blown cellulose is typically the preferred choice of insulation for attics.