Attic Insulation Over Blown In

Blown in fiberglass is considered flame resistant.

Attic insulation over blown in.

Blowing in insulation is a messy prospect and you ll need to wear a dust mask protective eyewear. Insulation efficiently fills gaps. This calculator is to be used as an estimating tool only. Input length width and desired r value of the area to be insulated.

Recruit a helper. Insulation should be rolled out perpendicular to the joists and unfaced rolls should be used. 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. Blown in insulation requires a professional.

Pull the existing insulation away from the roof. Install or repair vent chutes. 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. Pull back the existing insulation and use expanding spray foam the fire blocking type to seal any. Fiberglass is just that thin fibers of glass that trap air. Batt insulation take time to read this column.

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. Position the new vent chute so the. If you stand on joists in the. Before choosing blown vs.

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. Materials can be layered for added protection. We include blown in attic insulation pros and cons but we can t recommend blown in fiberglass or cellulose as your best insulating choice. Cellulose is recycled newsprint treated with a fire retardant.

Never stand on joists. The type of material you use is up to you. 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. The cost of blown in insulation is determined by which material you decide on the r value needed and the space of your attic.

Batt or rolled insulation or blown loose fill insulation fiberglass or cellulose can be installed on top of old insulation. If you choose loose fill insulation you ll need to rent a machine to install it. Blown in insulation flows down around wall studs. The vapor retarder on top of or between layers of insulation can trap moisture.

For an r value between 38 and 49 the average person spends about 1 50 each square foot. Click the button to calculate the depth in inches and pounds of total insulation required for this job.