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Blown-in insulation is one of the most common ways to insulate the attic, crawl space, or walls of a home. The average cost is about $1,355, with most homeowners spending between $875 and $1,893, but this is dependent on whether the work is done by the homeowner or by a professional. Most home improvement stores can supply rental blower units, but many homeowners find the option of a hired installer easier due to the large size of the job.Blown-in insulation increases the comfort of your home by neutralizing humidity and drafts and usually brings the largest return on investment.
Homeowners seeking to insulate their home with blown-in insulation will be pleasantly surprised at the efficiency and savings that come by completing this task. It increases the R-value of your home which substantially increases your energy efficiency, saving on the annual cost of heating and cooling. Blown-in fiberglass insulation isn't terribly expensive, especially with regard to how much efficiency it adds to your home. Add to that the benefit of quite a large savings for those doing it themselves versus the cost of paying a professional and it's actually quite cost-effective. For an average weight bag of 28.5 lbs., at an average cost of $33 a bag, a breakdown of amounts, costs, and labor combined are as follows:
Bags Per 1,000 Sq. Ft.
Installed Thickness (Inches)
It is important to note that the labor hours may change depending on what sort of machinery and equipment you use to do the job and the R-value you seek. Those who rent a machine to blow in the insulation, for example, will have considerably less trouble than those who do not. Furthermore, those who seek a higher R-value will need to blow in more material to achieve a greater depth. This is especially true for those who live in much colder regions who require an R-value above 30 to garner maximum protection. While this type of blow-in insulation isn't difficult to install overall, a small learning curve should also be applied to labor hours. Those homeowners with prior installation experience will no doubt have less trouble applying this product in the prescribed hours than those with no previous experience who might need some extra time to get a feel for how the process works.
Blown-in cellulose is the most common alternative to fiberglass and is sometimes used in conjunction with fiberglass. Cellulose is popular because it is a more natural material that is usually made from recycled newspaper, cardboard, or sometimes a combined mixture of each. Most cellulose is treated by a fire retardant called borate to increase its resistance to flame and to prevent house fires. The borate also makes it resistant to mold, mildew, and pests. For those looking for an eco-friendly insulation, cellulose is a more natural choice over man-made materials like fiberglass. Because of its ?green? status, its recycled content, and its benign impact on the environment as a whole, this type of blown-in insulation is more costly than its fiberglass counterpart. A 19 lb. package of blow-in cellulose, which covers approximately 40 square feet of space at the minimally recommended R-value, is around $28 - $30. Compare this to the table above where one package of blown-in fiberglass will cost you roughly the same, but cover nearly 150 square feet of space. That's nearly four times as much coverage for a comparable cost.
For minimum efficiency, an R-value of 30 is the recommended value for insulating your attic. An R-value of 30 will help your home achieve optimum thermal efficiency and reduce expenses related to heating and cooling your home. Insulating an attic with blow-in insulation is a fairly straightforward job. Because most attics are large, open spaces, the process doesn't require any unfamiliar techniques or methods that may require a professional. All you really need is your purchased insulation material, a machine to do the work, and perhaps a friend to help you. Therefore, when calculating costs and labor for 1000 square feet of attic space, the average homeowner should expect to pay:
$500 - $1,000 for materials
About $100 for equipment rental (which is sometimes offered for free with the purchase of a set amount of insulation)
For a total of $600 - $1,200
To hire a professional, who will come with a team of installers that can complete the job in a few hours, expect to pay between $40 - $70 an hour for labor. To save on costs, it's best to read online reviews and request quotes from several contractors to find competitive prices and deals before committing outright.
Using blown-in insulation to insulate walls and floors is more complex than insulating an attic. The installation requires a larger understanding of the inner workings of your home's walls, where electrical wiring and outlets are located, and requires the person doing the work to be handy, able to set aside a large chunk of time, and comfortable with drilling insertion holes in walls. Most experts advise homeowners to contact a professional to complete the job, especially if they are uncomfortable with the process or have no prior experience. Insulating walls and floors with blown-in insulation is also different than insulating an attic in terms of maximum achievable R-value. The reason is that the insulatable space inside of a wall or floor is considerably smaller than the open space of an attic. So without any negative space, the wall is filled almost completely. This contributes to a lower R-value for walls and floors but doesn't lessen the importance of insulation.
Bags Per 1,000 Sq. Ft.
Installed Thickness (Inches)
If you are intent on doing it yourself, here's a breakdown of the expected cost for a 1,000-square-foot home. Cost varies, and is determined by what type of material you choose (fiberglass or cellulose):
$450 - $1,000 for materials
About $100 for machine rental, unless you can find a free rental with a set purchase price of insulation
Totaling $550 - $1,075
Because the time it takes to insulate walls and floors is far greater than the time it takes to insulate an attic (several days versus several hours), hiring a professional is often advised. There is also a chance that a novice installer will make a mistake during installation, which may end up costing them more to repair. This fact alone might sway many into researching reputable installers instead of going it alone. For a cost analysis of hiring professionals, you can expect to pay roughly the same amount for materials as you would to do it yourself. However, because of how much work is involved with the process of installing insulation into floors and walls, the job can be costly. For labor costs expect to pay between $40 - $70 an hour. Because insulating walls and floors with blown-in insulation is more time-consuming and labor-intensive, the complete job will total between $1,200 and $1,800, a grand total that might make some want to complete it themselves, no matter the time it takes them.
When deciding whether to invest in blown-in insulation versus another type, it's important to realize how efficient blown-in insulation is. Blown in provides a seamless blanket over the boards of your attic. There's no way for air to get through it, as compared to batt insulation. It's also faster to install than batt or rolled insulation and costs less to install overall. One of the best advantages to installing this material is that it's considered ?renewable.? You can either install cellulose -- made of recycled newspapers -- or fiberglass, which is considered rapidly renewable. Other advantages to this material include:
Added longevity for the roof and shingles. A well-ventilated roof that includes an adequate layer of blown insulation can create a conditioned space in the attic. This conditioned space reduces the strain of heat on the sheathing that causes shingles to fail earlier.
Decrease in energy bills. Blown-in insulation can fill the crevices and cavities of attic space in ways that batting cannot. This creates a tight fit for little air gaps in the roof and eaves of the home, which saves a great deal of money by reducing the energy an air conditioner or furnace has to expend to heat or cool the home.
Vapor retarder and moisture barrier. Blown-in insulation that is installed correctly can reduce moisture infiltration. Maintaining the R-value keeps the house as warm as possible in the winter and cool in the summer. Adding an attic fan also helps to mitigate moisture that may infiltrate a vapor retarder near the insulation.
Fiberglass insulation is the most common residential insulation available on the market. Fiberglass is the least expensive blown-in insulation and offers the largest variety available. Blown-in fiberglass often comes in blocks that are blown through a machine into the floor joists of an attic or the interior walls. Fiberglass is usually used as a topper for existing cellulose insulation due to its additional fire-retardance. A tight fit in the stud wall cavity is necessary for the insulation to perform best. Blown-in fiberglass will need to be formed by code away from hot lights or other electrical equipment that produces heat.
Cellulose has a higher R-value than fiberglass per square inch. Cellulose is made of plant fibers and has some natural qualities that make it less hazardous to install by the homeowner. One small drawback of cellulose is the lack of an innate vapor retarder. Unlike natural rock wool and fiberglass, cellulose can become damaged if left wet for too long. It will require adequate additional insulation between joist spans, in addition to a vapor-retardant material on the insulated side facing the conditioned space. Cellulose is also available in natural fiber selections that allow for soundproofing and a reduced environmental impact.
Advantages of Cellulose:
Made from natural, recycled materials
Arguably the most energy-efficient of all blow-in insulation
Rock wool fiber is an environmentally friendly product that uses post-consumer recycled material and metals. It also has a naturally strong fire-retardant capacity, making it the most expensive blow-in insulation on the market. Despite the cost, the inorganic material adds exceptional soundproofing to the home in addition to its insulating capacity. This type of insulation also contributes to repelling insects and rodents naturally. When building code requires additional fire protection, mineral wool blow-in fiber is installed in stud cavities. One of the unique qualities of mineral wool is its ability to be "blown" in without the use of a mechanical blower machine. The material can be crumpled by hand because it is a natural product. A drawback to this method is the fact that it can take considerably longer to install versus cellulose or fiberglass.
The R-value of blown insulation is dependent on the density and insulating factors in the material. The higher the R-value, the more insulating capacity a material has. Most of the heat in a home or building escapes through the attic or roof sheathing. As a result, the densest form of blown-in insulation should be located in this portion of the house. Additional blow-in insulation in the walls adds additional insulative qualities and can act as a fire retardant in older buildings. An R-value of at least 45 provides adequate insulation for building code adjustments.