Blown In Insulation Over Batts

This light as air insulation is manufactured from glass that is heated to a liquid and then spun.

Blown in insulation over batts.

Batt or rolled insulation or blown loose fill insulation fiberglass or cellulose can be installed on top of old insulation. Blown in insulation often is a combination of loose fiberglass and treated cellulose fibers. Find out how to install unfaced insulation correctly over blown in insulation. Compared to blown in insulation batts can reach a resistance rating r factor of over 3 1.

Rolled insulation should not be tacked down. The r factor of blown in fiberglass is usually 2 3 to 2 8 per inch of material. Once installed and expanded to the uniform manufactured thickness batts offer a known r factor. Insulation should be rolled out perpendicular to the joists and unfaced rolls should be used.

Blown in insulation thickness can vary in an attic space. For eco minded homeowners cellulose is often the insulation of choice because it s made from finely. The maximum rating of batt insulation is around 4 2. The r value can be reduced if the insulation is squashed or flattened.

The depth and thickness of the blown insulation affect the r value. 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. Blown in varieties however typically reach a peak of around a 2 8 r factor. There are three types of blown in insulation.

Disadvantages of batt insulation.