Cellulose Vs Fiberglass Blown In Attic

Rather than trying to meticulously lay fiberglass insulation over the attic homeowners and builders can simply blow cellulose insulation throughout the attic.

Cellulose vs fiberglass blown in attic.

As the temperature difference between the living space and attic increases the r value of blown fiberglass diminishes. Higher r value per inch. Dry blown cellulose will characteristically settle and sag in place reducing its r value. Compared to fiberglass cellulose is a superb air blocker.

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. In extreme situations such as the upper midwest this reduction in r value approaches 50 percent. Loose fill blown fiberglass insulation has another slight problem. Since cellulose is blown in it fills all the gaps crevices nooks and crannies in your attic unlike batts that can leave gaps.

Blown cellulose is typically the preferred choice of insulation for attics. 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 in cellulose homeowner benefits. 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.

Cellulose retains more of its r value through a wider range of temperatures compared to fiberglass. 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 a recycled paper product cellulose is prone to absorb moisture that can cause wood rot and mould.

Fiberglass batts however are less expensive costing on average 0 30 to 0 40 a square foot for 6 inches of insulation. Loose fill or blown cellulose insulation is manufactured primarily from recycled newspapers a very benign product so it poses virtually no ongoing health risk. This is called wind washing. You can get to the same place with either material.

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. 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. Wet blown cellulose is also subject to similar contamination too. 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.