Attic Insulation Batts Over Blown

You d need a thickness of.

Attic insulation batts over blown.

Once installed and expanded to the uniform manufactured thickness batts offer a known r factor. Blown in insulation in the attic seal attic bypasses. Batt or rolled insulation or blown loose fill insulation fiberglass or cellulose can be installed on top of old insulation. Insulation should be rolled out perpendicular to the joists and unfaced rolls should be used.

Position the new vent chute so the. Notice how you don t see any of the ceiling framing down at the ceiling level. The first difference in blown in vs. Blown in insulation thickness can vary in an attic space.

In short there is less chance of error with blown insulation as compared to batts. That is about the only location that this insulation is used anymore as it is distributed uniquely. Pull back the existing insulation and use expanding spray foam the fire blocking type to seal any. Cellulose is recycled newsprint treated with a fire retardant.

Pull the existing insulation away from the roof. Any existing batt or roll insulation in the attic should have the facing against the attic drywall floor or no facing at all. Install or repair vent chutes. 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.

With this method the insulation is simply blown onto the attic floor and no matter what type of joists studs or wiring that may be in play the blown insulation will naturally form itself tight around any of these creating a layer of strong insulation. 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. 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.

The photo above shows an attic insulated with blown cellulose. Batt insulation is that it is a form of loose fill insulation as opposed to a flexible blanket. This will lead to non uniform r values. You also don t see any gaps that allow you to see all the way down to the ceiling drywall.

Fiberglass is just that thin fibers of glass that trap air. That s because blown insulation is great at filling the gaps and giving you a good complete layer of insulation. The material which is a combination of fiberglass and cellulose is blown in chunks to fill up space.