Add Attic Insulation Over Blown Insulation

You can add loose fill on top of fiberglass batts or blankets and vice versa.

Add attic insulation over blown insulation.

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. 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. Adding rolled batt or blown in insulation over existing insulation is not a problem. Don t add faced insulation on top of your existing insulation because the vapor retarder in between layers leads to trapped moisture.

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. We offer our review of the three most popular types of attic insulation with a look at each one s pros and cons. 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. 3 have a friend add material to the hopper.

If you need to add insulation in your attic save big by blowing in cellulose insulation yourself. Do not tack down any rolled insulation. How much does attic insulation cost. Batt or rolled insulation or blown loose fill insulation fiberglass or cellulose can be installed on top of old insulation.

The vapor retarder on top of or between layers of insulation can trap moisture. You d need a thickness of. When adding roll the insulation perpendicular to the joists not parallel. 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.

Blown in insulation overview. Blown in spray foam batts and blankets. Insulation should be rolled out perpendicular to the joists and unfaced rolls should be used. Find out how to install unfaced insulation correctly over blown in insulation.

It needs to be unfaced. Blowing attic insulation isn t hard but it s dusty sweaty work. 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. The pros charge 1 500 to 2 000 to do a 1 200 sq ft.

If you use fiberglass over loose fill make sure the fiberglass batt has no paper or foil backing. You can do it yourself for about 500. Fiberglass is just that thin fibers of glass that trap air. When adding additional insulation you do not have to use the same type of insulation that currently exists in your attic.