9 Best Attic Insulation Materials: A Comprehensive Review

Attic insulation keeps your home comfortable year-round. It ensures warmth in winter and coolness in summer by preventing heat from moving between your attic and other rooms. 

With different types of attic insulation available, choosing the right one can be challenging. To help you out, this blog post explores different options to help you find the best attic insulation material for your home.

Also Read: Top 5 Flat Roof Insulation Materials Of 2024

What Is The Best Insulation Material For An Attic?

#1. Cellulose Insulation

Cost: $0.60 – $4.20 per square foot 

The first option, cellulose insulation, is a popular choice in Wisconsin for its excellent thermal performance and eco-friendly composition. Made from recycled paper, it fills cracks and crevices, providing optimal coverage and air sealing. With an R-value of R-3.1 to R-3.8 per inch, it helps reduce energy costs and noise transmission. Professional installation is recommended due to concerns about settling and moisture.

PROS	CONS
Includes acrylic binder to prevent settling and R-value loss	Susceptible to moisture and mold if improperly installed
Good sound-dampening properties	Creates significant dust during installation
Treated with boric acid for fire and mold resistance	Messy installation, often requiring professional application

Review

Made from recycled materials, cellulose is a great choice for Wisconsin homes. It fits into tight spaces, sealing air leaks well. It works well in both cold winters and hot summers.

#2. Spray Foam Insulation

Cost: $0.50 – $7 per square foot

Ideal for Wisconsin’s varied climate, spray foam insulation offers excellent air sealing and thermal performance. Closed-cell spray foam, with an R-value of R-6 to R-7 per inch, is especially effective. Though it’s more expensive and requires professional installation, it resists moisture, mold, and pests, enhancing the building’s structural integrity and energy efficiency.

PROS	CONS
Excellent air sealing and insulation properties	Significantly more expensive than other options
Fills small gaps for superior air tightness	Difficult to remove or modify if needed
Can improve structural integrity	Potential health and environmental concerns

Review

With excellent thermal and air sealing performance, spray foam expands to fill gaps completely. It’s highly effective against Wisconsin’s extreme weather and maintains its insulation properties over time.

#3. Fiberglass Insulation

Cost: $0.30 – $1.50 per square foot

Widely used in Wisconsin, fiberglass insulation is cost-effective and easy to install. Available in batt and blown-in forms, it has an R-value of R-2.2 to R-4.3 per inch. It resists moisture, mold, and fire, providing good thermal and noise insulation. DIY installation is possible, but professional installation ensures optimal performance and minimizes air leaks.

PROS	CONS
Relatively inexpensive compared to other options	May settle over time, reducing effectiveness
Resistant to moisture, mold, and mildew	Susceptible to air leaks if improperly installed

Review

Fiberglass insulation is affordable but may leave gaps over time, reducing its effectiveness in Wisconsin’s climate. It’s a common choice but may not provide as much insulation as cellulose or spray foam.

#4. Polyisocyanurate (Polyiso) Insulation

Cost: $0.65 – $0.85 per square foot

Another great option, polyiso insulation, with an R-value of R-5.5 to R-6.5 per inch, is a top choice for Wisconsin’s roofing and wall applications. Its high thermal efficiency, moisture resistance, and long lifespan make it a durable option. While more expensive and harder to fit in uniquely shaped areas, its versatility and effectiveness in regulating indoor temperatures generally justify the investment.

PROS	CONS
Excellent fire resistance, forms a protective layer under high heat	R-Value decreases significantly below 50 degrees, less effective in cold climates.
Lightweight, easy to cut and install	Prone to moisture absorption, affecting performance in wet conditions
High R-value per inch, efficient insulation in less space	Foil facers can inadvertently act as an unwanted vapor barrier

Review

This rigid foam offers strong thermal performance and moisture resistance. It’s effective for Wisconsin’s climate but can be more expensive to install.

#5. Structural Insulated Panels (SIPs)

Cost: $10 – $18 per square foot

SIPs offer excellent thermal performance and structural support, making them ideal for Wisconsin homes. With an R-value of R-9 to R-21 per inch, these prefabricated panels ensure airtight construction, reducing energy costs. Though they have a higher upfront cost and require specialized installation, their durability and ease of installation are significant advantages.

PROS	CONS
Superior insulation and airtightness	Susceptible to moisture-related issues
Design flexibility, allowing for larger spans	Higher upfront costs compared to traditional options
Structural strength due to foam core and OSB facings	Potential ventilation challenges

Review

Combining foam insulation with structural panels, SIPs create a highly energy-efficient home envelope. They’re costly but beneficial for long-term energy savings in Wisconsin.

#6. Perlite Insulation

Cost: $1 – $1.50 per square foot

Perfect for Wisconsin attics, lightweight, naturally occurring perlite is used in buildings as a thermal insulator. Due to its non-toxicity, chemical inertness, and flexibility, it is frequently utilized as loose-fill insulation. Plus, it is fire-resistant, making it a long-lasting solution. Because of its superior thermal resistance, which contributes to the comfort of interior spaces, it is frequently used in Wisconsin homes.

PROS	CONS
Fire-resistant and naturally occurring	Lower R-value of R-3 per inch
Consistent thermal performance	Dusty during handling
Lightweight and pest-resistant	Susceptible to moisture
Cost-effective	Not a renewable resource

Review

Homeowners in Wisconsin value perlite for its ease of installation and soundproofing, especially in masonry homes. However, it can absorb moisture, which may affect its performance in very damp areas.

#7. Reflective Foil Insulation

Cost: $0.25 – $2.50 per square foot

Reflective foil insulation is effective in Wisconsin’s summers, reflecting radiant heat and keeping attics cooler. Easy to install, it reduces the load on air conditioning systems and lasts over 50 years. Though it has a lower R-value (R-1 to R-6 per inch) and requires proper installation, it doesn’t support mold growth, making it suitable for humid environments.

PROS	CONS
Effective at reflecting radiant heat, blocking up to 97% of heat transfer	Limited effectiveness in cold climates
Thin and lightweight, easy to install in tight spaces	Potential electrical hazards due to metallic foil facing
Acts as a vapor barrier when properly installed	Accumulation of dust and debris can reduce efficiency over time

Review

Reflective foil insulation deflects radiant heat but may not provide the comprehensive insulation needed for Wisconsin’s weather extremes. It’s suitable for specific applications and is best used along with other insulation materials.

#8. Rigid Foam Insulation

Cost: $0.60 – $2 per square foot

Rigid foam insulation, such as XPS or EPS, offers high thermal performance for Wisconsin homes. With R-values of R-5 to R-7 per inch, it reduces heat transfer and is moisture-resistant. Though more expensive and challenging to install in tight spaces, its durability and versatility make it a reliable long-term insulation solution.

PROS	CONS
Provides continuous insulation, reduces thermal bridging	Vulnerable to UV damage if not protected
May add structural strength	Challenging installation around obstructions
Versatile applications in various areas	Higher initial cost

Review

Moisture-resistant and providing an airtight barrier, rigid foam offers excellent thermal performance. It’s a bit more expensive but effective for Wisconsin homes.

#9. Mineral Wool Insulation

Cost: $1.40 – $4 per square foot

The last option on our list is mineral wool insulation, which is a safe, durable choice known for its fire resistance and thermal efficiency. With an R-value of R-3.5 to R-4.5 per inch, it also offers excellent sound insulation. Resistant to mold and pests, it’s a bit pricier and harder to install but ensures long-lasting performance and safety.

PROS	CONS
Effective fire resistance	Higher energy consumption and carbon footprint in manufacturing
Superior sound insulation and absorbs noise effectively	Challenging installation around obstructions
Moisture resistance maintains insulation properties when wet	Higher initial cost

Review

Natural and fire-resistant, mineral wool provides good thermal and acoustic insulation. It’s effective in Wisconsin but may be harder to install in tight spaces.

Conclusion

Choosing the right attic insulation is key to a comfortable and energy-efficient home. Consider your needs, budget, and local climate. Consulting a professional can help you make the best choice.

Trust BRH Enterprises for expert roofing services. We ensure quality installations, repairs, and maintenance for a protected, energy-efficient home. Experience professional service and quality craftsmanship with our team. Call us at (920) 249-4228.