When the existing insulation is too old, damaged, or worn to properly insulate the home, it’s time for an upgrade. On average, blown-in insulation costs $1,725, but the costs can range from about $750 to $3,800, depending on the type of insulation material, the area you are insulating, and the size of the space.
Meet the Expert
Brayden Montgomery is the owner and operator of Vantage Builders with years of hands-on experience as a general contractor.
Blown-In Insulation Cost by Type
On average, homeowners will spend $0.50 to $2.30 per square foot for materials, not including installation.
„As a general contractor, the cost of materials, like fiberglass, cellulose, and Rockwool insulation is typically the largest expense,” says Brayden Montgomery, Owner and Operator of Vantage Builders.
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Cellulose
Cellulose insulation is divided into dense-pack cellulose, which costs about $2 to $2.30 per square foot, and wet-spray cellulose, which costs $0.60 to $1.80 per square foot.
- Dense-pack cellulose has a higher cost than wet-spray cellulose, but it also has a higher R-value, making it a great option for old, drafty homes. However, this type of insulation isn’t easy for DIYers to work with, and may even take longer to install than wet-spray cellulose.
- Wet-spray cellulose is usually made from a mix of recycled newspaper, water, and chemicals that are then sprayed onto the walls, where the insulation rapidly dries. This type of insulation is more affordable than dense-pack cellulose, but it isn’t as effective and may leave gaps if it is not installed by an experienced professional.
Fiberglass
Fiberglass is the most common option for blown-in insulation because it’s both effective and affordable at an average cost of just $0.50 to $1.10 per square foot. Depending on the specific type of fiberglass blown-in insulation, homeowners may be able to find products that are fire-resistant or even pest-repellent.
Rockwool
Rockwool is a type of insulation made from rock and slag fibers, which is why it is also known as mineral wool. This type of blown-in insulation material has a high R-value and is naturally resistant to flame, moisture, and pests. It also offers a high level of noise insulation for the home, though all these great benefits come at a premium price when compared to other insulation materials. Plans to spend between $1.40 to $2.10 per square foot a Rockwool blown-in insulation.
Blown-In Insulation Costs by Area
Generally, installing insulation in an existing home will cost less than installing it in a newly constructed home, while insulation installation rates increase even further for attic installations.
Installing insulation in the walls of an existing home will typically cost about $1.75 to $3.50 per square foot. Homeowners that want the attic insulated as well, will need to set aside between $3 to $7.50 per square foot to complete this part of the home.
For new homes, it will usually cost between $2 to $4 per square foot to insulate the walls with blown-in insulation. However, prices may vary between contractors.
Blown-In Insulation Cost Factors
Size
Whether you are replacing the insulation in the attic, the exterior walls, or throughout the entire home, the size of the space needs to be taken into consideration. The greater the area, the higher the overall cost of the project. On average, homeowners can expect to pay about $1.65 to $3.80 per square foot.
Exact costs can vary based on the specific type of material, the location where the insulation will be installed, and the amount of insulation required to reach an appropriate R-value for the home.
Labor
The cost of labor ranges from about $40 to $70 per hour to have insulation blown in.
„The time required depends on attic size, usually taking a full day for typical attics,” Montgomery says. „Issues preventing installation are inadequate access, poor ventilation, or improperly sealed attics.”
This means that the cost of the project will increase for larger areas that are more difficult to access or that require sealing before the insulation can be installed. Specific labor prices vary between installation companies, so it’s a good idea to get estimates from at least three reputable companies.
R-Value
R-value is the capacity of the insulation to reduce the transfer of heat through the material. The higher the R-value of the material, the better it is at insulating the home, which is why insulation materials with a high R-value tend to be more expensive than insulation with lower R-values.
„High-density options providing an R-value of 30 to 60 per inch can cost $500 to $1500 for an average attic,” Montgomery says.
Generally, high R-values are best for homes located in colder regions of the country, while homes in warmer climates don’t require as much insulation to function properly. Check the local building codes and talk to the insulation pro about your options to find out what insulation material is best based on the required R-value for the home.
Geographic Location
The location of the home can also affect the cost of the project in more ways than one. If the home is located in an area with a high demand for insulating services, the cost of the project will typically be higher than if the home was located in a town with a low demand for this work.
The second way the geographic location impacts the cost is the local climate.
„Homeowners should ask about types of insulation, R-values for their climate, and warranty details,” Montgomery says.
Homes in colder climates will typically required more insulation to keep the home warm during the winter months, while homes that are built in more temperate areas will need less to insulate.
Additional Blown-In Insulation Costs
Old Insulation Removal
You may be able to pull out the existing insulation and dispose of it on you own to help reduce the cost of the project, but this can be a time-consuming process. If you don’t have the time, skill, or simply don’t want to handle the old insulation removal, this job can be left to the professionals for the average cost of $1 to $2 per square foot.
Mold and Asbestos Remediation
In most cases, mold and mildew will not naturally grow in blown-in insulation, but if the insulation is exposed to high levels of moisture, such as a leak or ongoing high-humidity levels, mold and mildew can become an issue. Removing mold and mildew can add about $2,250 to the cost of the job.
If the installers find that the home has asbestos insulation, then the asbestos will need to be professionally removed. Expect to spend about $2,100 for asbestos removal.
Air Sealing
Before insulating the home, the installers will typically look for any gaps, holes, or cracks that need to be air sealed.
„Extra fees may apply for attic sealing, ventilation, and access hatches,” Montgomery says.
The exact cost to air seal the building varies depending on the number, size, and location of the gaps or cracks, but it can generally range from a few hundred dollars to over $1,000.
Drywall Repairs
Depending on the current design of the home, the blown-in insulation installers may need to drill holes in the interior drywall or exterior sheathing. These holes allow the insulation to enter areas that were previously sealed, but before finishing the job, the installers will typically patch the drywall. However, not all insulation installers patch the drywall. In some cases, you may need to patch the holes yourself or hire a contractor to patch the holes for about $100 to $400 per hole.
Best Time of Year to Install Blown-In Insulation
Generally, the best time of the year to install blown-in insulation is when the temperatures are moderate during the spring and fall seasons. This is because the HVAC system is off or working at bare minimum levels, making it easy for the insulation contractor to conduct a thorough inspection and provide an accurate estimate for the work before the temperatures outside get too hot or too cold.
If you are looking to save on the cost of a blown-in insulation installation, consider booking in the late winter or late fall, when the demand for this work is relatively low. Some companies may offer deals during this period of the year to increase their earnings until the busy season arrives.
DIY Cost Factors
On average, DIYers that choose to handle a blown-in insulation project without the aid of the pros, will end up spending about $0.35 to $1.50 per square foot or $500 to $1,200, depending on the insulation type and location. Additionally, you will need to rent a blower, which costs about $125 per day.
You may also need to pay for products, like caulking, to seal any holes or gaps before the blown-in insulation can be installed. Otherwise, the insulation may escape into unwanted areas of the home.
Installing blown-in insulation is a two-person job. While one person feeds the insulation into the blower, the second person needs to direct the hose, so you will need to have a friend, family member, partner, or even a hired helper available.
Signs You Need Blown-In Insulation
Consider these few signs you can look out for to help determine when the home needs to have the existing insulation replaced or upgraded.
Drafts
Air drafts can sometimes enter through the insulating layers of the home if there are gaps in the existing insulation or if the insulation is in poor condition. If you feel drafts coming from the attic or the walls, then it’s a good idea to inspect the insulation to see if it is damaged or simply worn out. Replace or add to the existing insulation to block out drafts and protect the home.
High Energy Bills
The heating and cooling system keeps working until the temperature inside the home reaches the set level on the thermostat. However, if the walls or attic are improperly insulated, then there is a higher transfer of heat through the walls and roof of the home, leading to higher energy bills. Install new blown-in insulation to slow the transfer of heat and reduce your energy bills.
Insulation Age
The age of the insulation is a factor that’s important to keep in mind. While insulation is a long-lasting material that can often last for a decade before needing to be replaced, it can still wear out, reducing the overall efficiency of the home. Generally, if the insulation is older than 10 years, it should be replaced or more insulation should be added.
Moisture Problems
If your home has had recent issues with moisture, high humidity, or excessive mold growth, there is a chance that the insulation has been affected. Inspect the insulation for any signs of lingering moisture, mold, or mildew. Replace the insulation if it is highly contaminated by mold and mildew. Similarly, if the insulation seems too thin, worn, or otherwise damaged, it’s a good idea to replace or add to the insulation to improve home protection.
Uneven Temperatures
The main reason to have insulation is to help control the climate in the home. If the temperatures throughout the home seem to fluctuate from room to room, there is a high chance that the insulation is damaged, has gaps, or is simply insufficient to adequately insulate the home. Consider replacing or adding to the existing insulation.
Blown-In Insulation Pros and Cons
Pros
Blown-in insulation is relatively easy to install in attic spaces, so experienced DIYers may be able to handle this job without professional help. This type of insulation is also affordable, even for professional installation, when compared with many other types of insulation. Due to the method used for installation, blown-in insulation is ideal for filling hard-to-reach nooks and crannies, improving the efficiency of the home.
Like most other insulations, blown-in insulation can help to reduce energy bills for heating and cooling the home. It also offers improved sound-resistance. Similarly, some types of blown-in insulation are both fireproof and pest repellent, helping to protect the home.
Cons
Blown-in insulation is designed to fill the space where it is directed, but depending on the weight of the insulation in the attic, it can cause the ceiling to sag over time. Similarly, the composition of the insulation can absorb and hold onto moisture, creating issues with mold and mildew growth if it is exposed to leaks or high humidity.
While installing blown-in insulation in the attic is typically straightforward, it’s far more difficult to install this type of insulation in the walls. You have to use wet-blown insulation, which takes time to dry. If this process is not done properly, it can lead to problems with mold and mildew growth inside the walls.
5 Tips for Working With and Maintaining Blown-In Insulation
DIYers that choose to install blown-in insulation themselves or who want to keep up with insulation maintenance need to know how to safely work with this material.
- Wear personal protective equipment, which should include closed-toe shoes, long pants, a long-sleeve shirt, gloves, safety glasses, and a mask or respirator.
- Seal air leaks around pipes, wires, and any other gaps or holes that may otherwise allow the insulation to escape into unwanted areas.
- Monitor humidity levels in the attic and around the home to avoid moisture build-up that can cause damage to the insulation.
- Perform routine inspections every few months to ensure the insulation is clean, dry, and in good condition.
- Eliminate pest infestations as soon as possible to prevent pests from damaging or even nesting in the insulation.
FAQ
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Installing blown-in insulation is well worth the cost, as it helps to improve the home efficiency and reduce heating and cooling bills, while keeping the living space more comfortable for day-to-day life. Homes require insulation to slow the transfer of heat through the walls and roof of the home, ensuring the house remains cool in the summer and warm in the winter.
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The most affordable type of blown-in insulation is fiberglass, which costs about $0.50 to $1.10 per square foot.
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The amount of insulation that is necessary for the home depends on the type of insulation, the local climate, and the local building codes. Generally, homes in colder climates require higher R-values, so the insulation needs to be thicker, while homes in warmer areas of the country do not require as much insulation. Check your local building codes and work with the contractor to determine how thick blown-in insulation should be.