Blown In Insulation Vs Spray Foam Insulation – Best For Your Attic?

Insulating your attic is crucial for maintaining a comfortable home environment and reducing energy costs. When considering insulation options, two popular choices often come to mind: blown in insulation and spray foam insulation. Both have their advantages and considerations, so let’s delve deeper into each to determine which one is the best fit for your attic.

The Importance Of Insulation In Your Home

Before diving into the specifics of blown-in and spray foam insulation, let’s first understand the significance of insulation in your home. Insulation acts as a barrier, preventing heat transfer between the interior and exterior of your house. It helps maintain a consistent temperature, keeping your home warm in winter and cool in summer while reducing the load on your HVAC system. By effectively insulating your home, you can significantly reduce energy consumption and lower your utility bills.

What Is Blown-In Insulation And How Does It Work?

Blown-in insulation, also known as loose-fill insulation, is a popular choice for attics. It consists of loose particles, such as cellulose, fiberglass, or mineral wool, which are blown into the desired space using special equipment. The insulation material fills gaps, covers irregular surfaces, and forms a seamless layer that effectively traps air, providing excellent thermal resistance.

Pros And Cons Of Blown Insulation

Blown-in insulation offers several advantages. It provides excellent coverage, allowing it to reach even hard-to-reach areas and fill gaps effectively. This type of insulation is also relatively affordable and can be installed quickly. Additionally, blown-in insulation is made from eco-friendly materials, making it a sustainable choice.

However, blown-in insulation may settle over time, reducing its effectiveness. It can also be challenging to install in areas with obstructions or limited access. Furthermore, some types of blown-in insulation may require professional installation to ensure proper coverage and safety.

What Is Spray Foam Insulation And How Does It Work?

Spray foam insulation is a two-component mixture that combines isocyanate and polyol resin. When these components are mixed, they react chemically, expanding and forming a foam substance. This foam is then sprayed onto surfaces, creating a seamless and durable insulation layer.

Pros And Cons Of Spray Foam Insulation

Spray foam insulation has numerous advantages. It provides an airtight seal, effectively preventing air leakage and minimizing energy loss. It also offers excellent insulation performance with a high R-value, making it highly efficient in controlling temperature. Furthermore, spray foam insulation can provide structural support and soundproofing properties.

However, spray foam insulation tends to be more expensive compared to other insulation options. It requires professional installation due to the specialized equipment and expertise needed. Moreover, spray foam insulation may release volatile organic compounds (VOCs) during installation, which can be a concern for individuals with chemical sensitivities.

Blown-In Insulation Vs Spray Foam Insulation – Which Is Right For Your Attic?

The choice between blown-in insulation and spray foam insulation ultimately depends on various factors, including your budget, insulation goals, and attic conditions. Blown-in insulation is a cost-effective option that offers good coverage and versatility, making it suitable for most attics. On the other hand, spray foam insulation provides superior performance, especially in terms of air sealing and thermal resistance, but comes at a higher cost.

Consider consulting with a professional insulation contractor who can assess your attic’s specific requirements and recommend the best insulation solution based on your needs and budget.

Make The Right Choice To Insulate Your Attic

When it comes to insulating your attic, making an informed decision is crucial. Both blown-in insulation and spray foam insulation have their merits and considerations. Evaluate your priorities, seek professional advice, and consider factors such as insulation cost, performance, installation requirements, and environmental impact before selecting the best option for your attic.


Here are some frequently asked questions about blown-in foam insulation:

Is blown-in foam insulation worth it?

Yes, blown-in foam insulation is worth considering for its affordability, effectiveness in filling gaps, and energy-saving benefits. It provides good thermal resistance and can help reduce heating and cooling costs.

Is blown-in or foam insulation better?

Blown-in insulation and foam insulation serve different purposes. Blown-in insulation is more versatile, as it can fill irregular spaces and cover large areas effectively. Foam insulation, on the other hand, provides superior air sealing and insulation performance. The choice depends on your specific insulation needs and budget.

What are the disadvantages of spray foam insulation?

While spray foam insulation has numerous benefits, it also has some drawbacks. It tends to be more expensive than other insulation options, requires professional installation, and can release volatile organic compounds (VOCs) during application. Additionally, it may not be suitable for areas with high humidity.

What is the cost of blown-in foam insulation?

The cost of blown-in foam insulation varies depending on factors such as the size of the area to be insulated, the type of insulation material used, and the region’s labor rates. It is recommended to obtain quotes from insulation contractors to get an accurate estimate for your specific project.

What are the disadvantages of blown-in insulation?

While blown-in insulation is generally effective, it may settle over time, reducing its insulation properties. Installation in areas with obstructions or limited access can be challenging. Additionally, some types of blown-in insulation may require professional installation for proper coverage and safety.

When should you not use spray foam insulation?

Spray foam insulation may not be suitable in certain situations. For example, if you have an existing moisture issue in your attic, it’s important to address that before considering spray foam insulation. Additionally, if you have budget constraints, other insulation options may be more cost-effective.

What is the best insulation for attic heat?

Both blown-in insulation and spray foam insulation can effectively reduce heat transfer in the attic. Spray foam insulation provides superior air sealing and insulation performance, making it an excellent choice for combating attic heat. However, blown-in insulation can also provide adequate heat resistance when properly installed.

What is the most effective blown-in insulation?

There are various types of blown-in insulation, including cellulose, fiberglass, and mineral wool. Each type has its own advantages and effectiveness. Cellulose insulation, made from recycled paper, is known for its excellent thermal resistance and fire retardant properties. Fiberglass and mineral wool are also effective choices, providing good insulation performance.

What is the best insulation to use in your attic?

The best insulation for your attic depends on your specific needs, budget, and regional climate. Blown-in insulation, such as cellulose or fiberglass, is a popular choice for attics due to its ability to fill gaps and provide good coverage. Spray foam insulation is another high-performance option, especially for air sealing and thermal resistance.

Does spray foam decrease home value?

The impact of spray foam insulation on home value can vary depending on several factors. While spray foam insulation can enhance energy efficiency and comfort, some potential buyers may have concerns about its installation, cost, or potential off-gassing of VOCs. It’s advisable to consult with local real estate professionals to assess the market impact in your area.

How long does foam insulation last?

Foam insulation is known for its durability and long lifespan. When installed correctly, it can last for several decades without significant degradation. However, factors such as exposure to moisture, physical damage, or improper installation can affect its longevity. Regular inspections and maintenance can help ensure its effectiveness over time.

Should I foam insulate my attic?

Foam insulation can be a suitable choice for insulating your attic, especially if you desire superior air sealing and insulation performance. It helps create a tight thermal envelope, minimizing heat loss and reducing energy consumption. However, before making a decision, consider factors such as your budget, insulation goals, and the specific characteristics of your attic. Consulting with a professional insulation contractor can provide valuable guidance tailored to your situation.

How much does a 55-gallon drum of spray foam cover?

The coverage provided by a 55-gallon drum of spray foam insulation depends on the specific product and application thickness. Generally, a single 55-gallon drum can cover a substantial area, ranging from several hundred to several thousand square feet. It’s best to consult the manufacturer’s specifications or seek advice from insulation professionals to determine the exact coverage for your project.

How long do you have to stay out of the house after spray foam?

After spray foam insulation is applied, it needs time to cure and off-gas. The duration can vary depending on the specific product, environmental conditions, and the size of the area insulated. In most cases, it is recommended to stay out of the house for a minimum of 24 to 48 hours to allow the foam to fully cure and any residual fumes to dissipate. Following the manufacturer’s instructions and consulting with the insulation contractor is crucial for ensuring proper safety measures.

Can I spray foam insulation myself?

While it is possible to purchase DIY spray foam insulation kits, applying spray foam insulation yourself can be challenging and potentially risky. Proper installation requires specialized equipment, knowledge of insulation techniques, and an understanding of safety protocols. It is generally recommended to hire a professional insulation contractor who has the expertise and experience to ensure correct installation, optimal performance, and safety.

Is blown-in insulation bad for your lungs?

Blown-in insulation, when made from materials such as cellulose or fiberglass, is generally considered safe when installed correctly. However, during the installation process, it is essential to take proper precautions such as wearing protective gear, such as a mask and gloves, to minimize the inhalation of particles. If you have respiratory sensitivities or concerns, consult with insulation professionals or medical experts for personalized advice.

Is blown-in insulation cancerous?

Blown-in insulation, when composed of materials such as cellulose or fiberglass, is not inherently cancerous. These materials have undergone extensive testing and are considered safe for residential use. However, it is crucial to follow proper installation guidelines and safety measures to ensure a healthy indoor environment. If you have specific health concerns, it’s advisable to consult with insulation professionals or medical experts for personalized information.

Is blown-in insulation a fire hazard?

Blown-in insulation made from materials such as cellulose or fiberglass is treated with fire-retardant substances, reducing its flammability. When installed properly and in accordance with building codes, blown-in insulation poses minimal fire hazard. However, it’s important to ensure that electrical wiring, recessed lights, and other potential ignition sources are properly protected and in compliance with safety standards. Following safety guidelines and consulting with insulation professionals can help mitigate any fire risks.

Do I need roof vents if I have spray foam insulation?

The necessity for roof vents depends on several factors, including the type of spray foam insulation used and the specific characteristics of your attic. Closed-cell spray foam, for example, acts as an effective air and moisture barrier, reducing the need for roof vents. However, proper ventilation is still crucial to prevent moisture buildup and maintain attic health. Consulting with insulation professionals and considering local building codes and guidelines can help determine the appropriate ventilation strategy for your attic.

Can you spray foam the underside of your roof?

Spray foam insulation can be applied to the underside of the roof, a technique known as spray foam roofing. This method involves spraying a layer of foam insulation directly onto the underside of the roof deck, creating a seamless and highly insulating barrier. Spray foam roofing provides excellent thermal insulation, air sealing, and protection against moisture infiltration.

However, it’s important to note that spray foam roofing requires professional installation and expertise. The process involves careful surface preparation, proper application techniques, and adherence to safety protocols. Additionally, local building codes and regulations may have specific requirements for spray foam roofing. Consulting with experienced spray foam contractors is essential to ensure a successful and long-lasting application.

Does expanding foam stop mice?

Expanding foam insulation can help deter mice and other rodents from entering your home. The foam’s expansion and solidification create a physical barrier that can seal off small openings and gaps where rodents may gain access. However, it’s important to note that expanding foam alone may not be a foolproof solution, as mice can still find alternative entry points. To effectively prevent rodent infestation, it’s recommended to combine expanding foam insulation with other rodent-proofing measures, such as sealing exterior openings, maintaining proper sanitation, and employing traps or baits if necessary.

Do you have to drywall over spray foam insulation?

In many cases, it is not necessary to cover spray foam insulation with drywall. Spray foam insulation can act as both an insulation and an air barrier, providing effective thermal resistance and air sealing properties. However, local building codes and regulations may have specific requirements regarding the use of spray foam insulation and the need for a covering such as drywall. It’s important to consult with local building authorities or insulation professionals to ensure compliance with applicable regulations.

Will closed cell spray foam rot my roof?

Closed-cell spray foam insulation is generally not known to cause roof rot. In fact, it can provide added protection to your roof by acting as a moisture barrier and preventing water infiltration. Closed-cell spray foam has a high density and a closed-cell structure, making it resistant to moisture absorption and water damage. However, it’s crucial to ensure proper installation and address any existing roof issues before applying spray foam insulation. Regular roof inspections and maintenance are also essential for maintaining the overall health and longevity of your roof.

What is better spray foam or fiberglass?

The choice between spray foam insulation and fiberglass insulation depends on various factors, including your insulation goals, budget, and specific requirements. Spray foam insulation offers superior air sealing, thermal resistance, and versatility in filling gaps and irregular spaces. It can provide a more efficient and airtight insulation solution. Fiberglass insulation, on the other hand, is a more affordable option that still offers good thermal performance when properly installed.

Both spray foam and fiberglass insulation have their advantages and considerations. It’s advisable to assess your needs, consult with insulation professionals, and consider factors such as energy efficiency, air sealing requirements, budget constraints, and local building codes to determine which option is better suited for your specific project.

What is the cheapest most effective way to insulate an attic?

Blown-in insulation, such as cellulose or fiberglass, is often considered one of the most cost-effective ways to insulate an attic. It provides good thermal resistance, effective coverage, and is generally more affordable compared to other insulation methods. Blown-in insulation can be installed quickly and easily, allowing for cost savings in terms of labor. However, it’s important to ensure proper installation and adequate insulation depth to achieve optimal energy efficiency and comfort.

Which is better attic insulation blown or rolled?

The choice between blown-in insulation and rolled insulation for attic insulation depends on several factors, including your attic’s specific characteristics and your insulation goals. Blown-in insulation offers better coverage, especially in hard-to-reach areas and irregular spaces. It can effectively fill gaps and provide more uniform insulation. Rolled insulation, such as fiberglass batts or rolls, is easier to handle and install in open areas with clear access. It can be a suitable option for attics with standard joist spacing and minimal obstructions.

Both blown-in and rolled insulation can provide effective thermal resistance when installed correctly. The choice ultimately depends on factors such as your attic’s layout, the presence of obstructions, and your insulation preferences. Consulting with insulation professionals can help determine the most suitable option for your specific attic.

Can you over insulate an attic?

While insulation is crucial for energy efficiency, comfort, and reducing heat transfer, it is possible to over insulate an attic. Over-insulation can lead to excessive condensation and moisture buildup, which can cause mold growth, structural damage, and other issues. It’s important to follow insulation guidelines and recommended insulation levels for your region.

The appropriate insulation level for an attic depends on factors such as climate, the type of insulation used, and local building codes. Insulation professionals can assess your attic’s insulation needs and recommend the optimal insulation thickness or R-value to achieve energy efficiency without risking moisture problems.

How often should attic insulation be replaced?

Attic insulation does not typically have a set expiration date and does not need to be replaced regularly. However, insulation can degrade over time due to factors such as settling, moisture damage, pests, or physical damage. It’s important to periodically inspect your attic insulation for signs of deterioration, such as compression, moisture stains, or mold growth.

If you notice any significant damage or a substantial decrease in insulation performance, it may be necessary to replace or add insulation to maintain optimal energy efficiency. Consulting with insulation professionals can help assess the condition of your attic insulation and determine if replacement or additional insulation is needed.

Can blown-in insulation be used in walls?

Blown-in insulation can be used in walls, providing an effective method of insulating enclosed spaces. It is commonly used in retrofit projects where access to the wall cavity is limited. Blown-in insulation, such as cellulose or fiberglass, is blown into the wall cavities using specialized equipment. It fills voids and gaps, improving thermal performance and reducing air infiltration.

Professional installation is recommended for blown-in insulation in walls to ensure proper coverage, density, and adherence to fire safety regulations. It’s important to consult with insulation experts or contractors experienced in wall insulation to determine the suitability of blown-in insulation for your specific walls.

What are the benefits of radiant barrier insulation?

Radiant barrier insulation offers several benefits when installed in attics or other areas with direct sun exposure. It helps reflect radiant heat away from the living space, reducing heat transfer and keeping the area cooler. This can result in energy savings and improved comfort, especially in hot climates.

Radiant barrier insulation typically consists of a reflective foil material installed on the underside of the roof or on attic surfaces. It complements other forms of insulation by reducing heat gain through radiation. However, it’s important to note that radiant barrier insulation is most effective in sunny climates and during the cooling season.

Is blown-in foam insulation suitable for soundproofing?

Blown-in foam insulation, such as cellulose or fiberglass, can provide some level of soundproofing when installed correctly. It helps reduce airborne sound transmission by absorbing sound waves and reducing their propagation. However, it’s important to note that the soundproofing capabilities of blown-in foam insulation may not be as effective as specialized soundproofing materials or techniques.

For optimal soundproofing results, additional measures such as using resilient channels, double layers of drywall, or acoustic panels may be required. Consulting with soundproofing experts can provide tailored solutions for your specific soundproofing needs.

Remember, when it comes to insulation and home improvement projects, it’s essential to consult with professionals, adhere to local building codes, and prioritize safety. Proper installation and compliance with regulations ensure optimal performance and longevity of your insulation system.

Can blown-in insulation cause allergies or respiratory issues?

Blown-in insulation, when made from materials like cellulose or fiberglass, is generally considered safe for residential use. However, during the installation process, it’s important to take precautions to minimize the release of particles into the air. This includes wearing protective gear, such as masks and gloves, and following safety guidelines provided by the insulation manufacturer.

While blown-in insulation itself is not known to cause allergies or respiratory issues, individuals with pre-existing sensitivities or respiratory conditions may experience discomfort if exposed to airborne particles. If you have concerns about potential allergic reactions or respiratory issues, it’s advisable to consult with insulation professionals or healthcare experts for personalized advice.

Does spray foam insulation emit harmful gases?

Spray foam insulation can emit gases during the application and curing process. These gases, known as volatile organic compounds (VOCs), may include chemicals like isocyanates. While spray foam manufacturers have made significant efforts to reduce VOC emissions, it’s important to ensure proper ventilation during and after installation.

Most spray foam installations require a designated curing period to allow the foam to off-gas and fully cure. During this time, it’s recommended to ventilate the area by opening windows and using fans to facilitate air circulation. Following the manufacturer’s instructions and allowing sufficient time for the foam to cure and off-gas helps minimize the potential exposure to harmful gases.

How do I find a reputable insulation contractor?

Finding a reputable insulation contractor is essential for a successful insulation project. Here are some tips to help you find a reliable professional:

  1. Seek recommendations: Ask friends, family, or neighbors who have recently had insulation work done for recommendations. Personal referrals are often reliable sources of information.
  2. Research online: Look for reputable insulation contractors in your area. Check their websites, read customer reviews, and assess their experience and credentials.
  3. Verify credentials: Ensure that the contractor holds the necessary licenses and certifications required by your state or region. This may include certifications from insulation manufacturers or industry associations.
  4. Request estimates: Contact multiple insulation contractors and request detailed estimates for your project. Compare the pricing, scope of work, and materials used to make an informed decision.
  5. Check references: Ask the contractors for references from previous clients. Contact these references and inquire about their experience with the contractor, quality of work, and customer satisfaction.
  6. Interview the contractor: Schedule a meeting or phone call with potential contractors to discuss your project. Ask about their experience, techniques, and materials used. A professional contractor should be knowledgeable, transparent, and able to address your concerns.
  7. Obtain written contracts: Once you have selected a contractor, ensure that all project details, timelines, and costs are documented in a written contract. This protects both parties and ensures clear expectations.

By following these steps, you can increase your chances of finding a reputable and qualified insulation contractor for your project.

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