Add Attic Insulation Over Blown Insulation

The vapor retarder on top of or between layers of insulation can trap moisture.

Add attic insulation over blown insulation.

If you use fiberglass over loose fill make sure the fiberglass batt has no paper or foil backing. Your options for attic insulation range from radiant barriers to sheets of mineral wool but most homeowners stick with products made from cellulose or fiberglass. The attic is the most important place to install insulation b ecause heat rises to make your home more energy efficient it is important to insulate the floor of the attic. Block all vents in the attic floor with baffles making sure to extend the baffles at least four inches above the planned thickness of your insulation.

Any existing batt or roll insulation in the attic should have the facing against the attic drywall floor or no facing at all. Attic insulation also prevents condensation bacteria and mold from forming on your framing members and plywood roof sheathing. 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. Batt or rolled insulation or blown loose fill insulation fiberglass or cellulose can be installed on top of old insulation.

You can add loose fill on top of fiberglass batts or blankets and vice versa. Blowing attic insulation isn t hard but it s dusty sweaty work. We offer our review of the three most popular types of attic insulation with a look at each one s pros and cons. Do not tack down any rolled insulation.

3 have a friend add material to the hopper. You can do it yourself for about 500. Find out how to install unfaced insulation correctly over blown in insulation. Most attics are insulated with blown in loose cellulose r 3 5 per inch blown in loose fiberglass r 2 5 per inch or fiberglass batts r 3 2 per inch.

Blown in insulation overview. Don t add faced insulation on top of your existing insulation because the vapor retarder in between layers leads to trapped moisture. 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. Blown in spray foam batts and blankets.

Adding rolled batt or blown in insulation over existing insulation is not a problem. It needs to be unfaced. Insulation should be rolled out perpendicular to the joists and unfaced rolls should be used. The pros charge 1 500 to 2 000 to do a 1 200 sq ft.

When adding roll the insulation perpendicular to the joists not parallel. You d need a thickness of. Fiberglass is just that thin fibers of glass that trap air. How much does attic insulation cost.