Adding Fiberglass Batts To Attic Blown In Insulation

Working with fiberglass insulation requires wearing personal protection gear.

Adding fiberglass batts to attic blown in insulation.

Blown in insulation thickness can vary in an attic space. Fiberglass comes from what i ve heard one major fiberglass insulation manufacturer call a rapidly renewable resource sand. 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. Install fiberglass batts over existing batt insulation.

Place the batts into. Batt or rolled insulation or blown loose fill insulation fiberglass or cellulose can be installed on top of old insulation. You d need a thickness of. The material tends to compress over time.

Cut fiberglass batts by scoring them with a utility knife. Size each piece to fit snugly between the floor joists in your attic. Insulation should be rolled out perpendicular to the joists and unfaced rolls should be used. I don t know about that but it s a common insulation material that works much better in the blown form than in batts.

Put on goggles and gloves to protect yourself while handling fiberglass 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 consists of bags of fiberglass or cellulose that are chopped up and blown in to the attic or wall from a machine. Batts and blankets can leave gaps and voids.

This will lead to non uniform r values. Don t forget attic pipes. The r factor of blown in fiberglass is usually 2 3 to 2 8 per inch of material. The photo above shows an attic insulated with blown cellulose.

To keep the blown in insulation from falling through the attic hatch opening make a 2x12 dam around the hatch perimeter. When blown into attics and wall spaces loose fill fiberglass offers an average r 2 5 thermal value per inch the higher the number the greater the insulating effect. 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. 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.

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