Add Attic Insulation Over Blown Insulation

If blown in insulation is used control the height or thickness of the layers so boards can by laid over top without having to compact the filler.

Add attic insulation over blown insulation.

To keep the blown in insulation from falling through the attic hatch opening make a 2x12 dam around the hatch perimeter. Place flooring over insulation to make your attic space functional. Spray foam attic insulation image. 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.

Plan to pull up the flooring and layer new insulation on top of the old. Spray insulation to the corners and perimeter of the attic first working your way into the center. Direct the blower away from the baffles and attic stairs to minimize cleanup. The method of installation matters too.

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. Damp blown in insulation can promote fungal growth. You need about 22 inches of blown in or about 19 inches of unfaced insulation in that attic space to give you the maximum amount of warmth. Attics are generally covered in batting or blown insulation.

Insulation should be rolled out perpendicular to the joists and unfaced rolls should be used. Putting faced insulation over old insulation in an attic is a big no no because it will trap moisture and lead to long term problems. Similarly you must take care not to tack down or flatten any rolled insulation as doing so will compromise its effectiveness. Batt or rolled insulation or blown loose fill insulation fiberglass or cellulose can be installed on top of old insulation.

Because the simplest and cheapest way to insulate an attic is to add material to the floor. Insulation should be rolled out perpendicular to the joists and unfaced rolls should be used. Any existing batt or roll insulation in the attic should have the facing against the attic drywall floor or no facing at all. Dunktanktechnician via flickr cc by sa 2 0.

Batt or rolled insulation or blown loose fill insulation fiberglass or cellulose can be installed on top of old insulation. As you compare spray foam attic insulation pros and cons keep in mind that the material is available as an open cell or closed cell polyurethane spray foam. The material becomes very problematic when wet.