Adding Fiberglass Batts To Attic Blown In Insulation

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Adding fiberglass batts to attic blown in insulation.

Install fiberglass batts over existing batt insulation. Size each piece to fit snugly between the floor joists in your attic. To keep the blown in insulation from falling through the attic hatch opening make a 2x12 dam around the hatch perimeter. Batt or rolled insulation or blown loose fill insulation fiberglass or cellulose can be installed on top of old insulation.

Any existing batt or roll insulation in the attic should have the facing against the attic drywall floor or no facing at all. Blown in insulation thickness can vary in an attic space. Fiberglass is considered the best attic insulation for diy projects. I don t know about that but it s a common insulation material that works much better in the blown form than in batts.

The r factor of blown in fiberglass is usually 2 3 to 2 8 per inch of material. Insulate your attic with fiberglass batts when it comes to insulating your attic there are really only two types of insulation worth considering fiberglass batts or blown in insulation. Don t forget attic pipes. The photo above shows an attic insulated with blown cellulose.

Cut fiberglass batts by scoring them with a utility knife. Batts and blankets can leave gaps and voids. Once installed and expanded to the uniform manufactured thickness batts offer a known r factor. Fiberglass comes from what i ve heard one major fiberglass insulation manufacturer call a rapidly renewable resource sand.

Insulation should be rolled out perpendicular to the joists and unfaced rolls should be used. The material tends to compress over time. To install fiberglass batts over existing insulation lay the batts perpendicular to the joists so they do not compress the insulation below whether you live in a warm weather state as i do or in a cooler northern climate it s hard to stay comfortable and keep your energy bills in check if you don t have adequate insulation in the attic. Because blown in insulation which is fiberglass generally can go on top of the existing insulation the negative thing about blown in insulation is that it makes the attic absolutely impassable when you re done and you need a lot more thickness of it because it has more air inside of it than you would if you used fiberglass bats.

Batts don t fit well in odd spaces. This will lead to non uniform r values. Cut two layers of r 19 fiberglass batt insulation slightly larger than the hatch and staple duct tape to the hatch edges to secure it in place. Put on goggles and gloves to protect yourself while handling fiberglass insulation.

Blown in insulation consists of bags of fiberglass or cellulose that are chopped up and blown in to the attic or wall from a machine.