Attic Insulation Batts Over Blown

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

Attic insulation batts over blown. Any existing batt or roll insulation in the attic should have the facing against the attic drywall floor or no facing at all. That is about the only location that this insulation is used anymore as it is distributed uniquely. 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 first difference in blown in vs.

The r factor of blown in fiberglass is usually 2 3 to 2 8 per inch of material. Insulation should be rolled out perpendicular to the joists and unfaced rolls should be used. This will lead to non uniform r values. Position the new vent chute so the.

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. The photo above shows an attic insulated with blown cellulose. You d need a thickness of. Pull back the existing insulation and use expanding spray foam the fire blocking type to seal any.

The material which is a combination of fiberglass and cellulose is blown in chunks to fill up space. Install or repair vent chutes. 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. In short there is less chance of error with blown insulation as compared to batts.

That s because blown insulation is great at filling the gaps and giving you a good complete layer of insulation. It is sold in bags and made of materials that are of varying degrees of recycled. Cellulose is recycled newsprint treated with a fire retardant. 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 insulation thickness can vary in an attic space. You also don t see any gaps that allow you to see all the way down to the ceiling drywall. Batt insulation is that it is a form of loose fill insulation as opposed to a flexible blanket. 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.

Blown in insulation in the attic seal attic bypasses. Since the attic usually does not have any wall on the other side this insulation makes some sense in that regard. Pull the existing insulation away from the roof.