Attic Insulation Over Blown In

Batt or rolled insulation or blown loose fill insulation fiberglass or cellulose can be installed on top of old insulation.

Attic insulation over blown in. Loose fill blown in insulation is best for tight spaces or if your attic already has a layer of insulation that just needs to be topped off. Never stand on joists. Any existing batt or roll insulation in the attic should have the facing against the attic drywall floor or no facing at all. Before choosing blown vs.

Cellulose is recycled newsprint treated with a fire retardant. Always cover the tops of the ceiling joists to make sure the insulation is deep enough to reach your target r value and to prevent thermal bridging the heat loss that occurs through the wood framing. Someone needs to load the bags of insulation into the blower which will remain on the floor below. Blown in insulation in the attic seal attic bypasses.

Batt insulation is available at home centers and lumberyards. Work from the perimeter of the attic toward the door or hatch so that you don t trample all over the insulation you just put in. Insulation efficiently fills gaps. 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 flows down around wall studs. Pull back the existing insulation and use expanding spray foam the fire blocking type to seal any. If you stand on joists in the. If you choose loose fill insulation you ll need to rent a machine to install it.

Insulation should be rolled out perpendicular to the joists and unfaced rolls should be used. Pull the existing insulation away from the roof. Fiberglass is just that thin fibers of glass that trap air. Attic insulation is accomplished with either fiberglass blankets batt or blown in insulation.

Blown in insulation requires a professional. Blown in fiberglass is considered flame resistant. The cost of blown in insulation is determined by which material you decide on the r value needed and the space of your attic. Materials can be layered for added protection.

For an r value between 38 and 49 the average person spends about 1 50 each square foot. This calculator is to be used as an estimating tool only. Don t forget to factor in whether you will be renting a blow machine or hiring someone to do it for you. Input length width and desired r value of the area to be insulated.

Position the new vent chute so the. The type of material you use is up to you. The vapor retarder on top of or between layers of insulation can trap moisture. Click the button to calculate the depth in inches and pounds of total insulation required for this job.

Blowing in insulation is a messy prospect and you ll need to wear a dust mask protective eyewear. Recruit a helper.