Blown In Insulation Over Batts

Once installed and expanded to the uniform manufactured thickness batts offer a known r factor.

Blown in insulation over batts.

This light as air insulation is manufactured from glass that is heated to a liquid and then spun. The r factor of blown in fiberglass is usually 2 3 to 2 8 per inch of material. The r value can be reduced if the insulation is squashed or flattened. Blown in insulation thickness can vary in an attic space.

Batt or rolled insulation or blown loose fill insulation fiberglass or cellulose can be installed on top of old insulation. Find out how to install unfaced insulation correctly over blown in insulation. The insulation usually is blended and provides an r value ranging from around 32 to 38 per square foot. Blown in varieties however typically reach a peak of around a 2 8 r factor.

This will lead to non uniform r values. There are three types of blown in insulation. Disadvantages of batt insulation. For eco minded homeowners cellulose is often the insulation of choice because it s made from finely.

Learn how one caller made an installation mistake and increased his chances of mold and condensation when he tried to add unfaced insulation over his blown in attic insulation. Rolled insulation should not be tacked down. Loosely blown fiberglass alone carries an r value of about 22 to 27 per square foot. Compared to blown in insulation batts can reach a resistance rating r factor of over 3 1.

The maximum rating of batt insulation is around 4 2.