Attic insulation has many useful purposes for your home. It can help:
- regulate indoor temperature
- reduce energy costs
- and protect your home from moisture problems
Properly insulated attics can also extend the life of your roof and heating and cooling systems. However, it’s not always easy to know the best kind of insulation for your attic and home. Here, we discuss the seven most popular types of attic insulation alongside their pros and cons.
1. Batt Insulation
Batt insulation is one of the most common types of insulation. It comes in large rolls or sheets, typically made from fiberglass, although mineral wool and cotton are also used. This insulation is manufactured by weaving fine glass or mineral fibers together to form a thick, fluffy material. Installation involves cutting the batts to fit snugly between the joists or studs in the attic space.
Pros
- Ease of Installation: Batt insulation is relatively easy to install, even for DIY enthusiasts.
- Cost-Effective: This type is generally more affordable than other forms of insulation.
- Availability: Widely available at most home improvement stores.
- Fire-Resistant: Fiberglass batts are non-combustible, offering an extra layer of fire safety.
Cons
- Gaps and Voids: Poor installation can leave gaps, reducing its effectiveness.
- Moisture Problems: Susceptible to moisture retention, which can lead to mold growth.
- Skin Irritation: Fiberglass can cause skin and respiratory irritation during installation.
- Lower R-Value: Compared to other insulation types, batt insulation has a lower R-value per inch.
2. Blown-In Insulation
Blown-in insulation, also known as loose-fill insulation, is made from small particles of fiberglass, cellulose, or mineral wool. It is installed using a blowing machine, which sprays the particles into the attic space to fill gaps and cover surfaces evenly.
Pros
- Comprehensive Coverage: Fills gaps and cavities more effectively than batt insulation.
- Sound Insulation: Excellent for reducing noise transmission through walls and ceilings.
- Quick Installation: Professionals can install blown-in insulation quickly and efficiently.
- Recycled Materials: Cellulose blown-in insulation is often made from recycled paper products.
Cons
- Settling: Over time, blown-in insulation can settle, reducing its R-value.
- Moisture Absorption: Particularly with cellulose, moisture can be absorbed, leading to mold and mildew.
- Professional Installation Needed: Requires specialized equipment and expertise to install correctly.
- Dust and Debris: The installation process can be messy and create dust.
3. Spray Foam Insulation
Spray foam insulation is a two-part liquid that expands into a foam, creating a solid, insulating layer upon curing. It can be applied directly to the surfaces of the attic, filling every gap and crevice.
Pros
- High R-Value: Provides a higher R-value per inch than most other insulation types.
- Air Barrier: Acts as both an insulator and an air barrier, sealing leaks and gaps.
- Moisture Resistance: Closed-cell foam offers excellent resistance to moisture.
- Structural Support: Adds rigidity and strength to the structure where applied.
Cons
- Cost: One of the more expensive insulation options.
- Professional Installation Required: Needs to be installed by trained professionals due to chemical handling.
- Off-Gassing: Can emit gases during and after installation, requiring adequate ventilation.
- Difficult to Remove: Once installed, it is challenging to remove or replace.
4. Rigid Foam Insulation
Rigid foam insulation comes in panels or boards made from polystyrene, polyisocyanurate, or polyurethane. These boards are cut to fit and installed against the attic’s structural components.
Pros
- High R-Value: Provides an excellent R-value per inch, making it highly efficient.
- Moisture Resistance: Resists moisture absorption, reducing the risk of mold.
- Durable: Long-lasting and resistant to compression and damage.
- Easy Installation: Panels can be easily cut and fitted into place.
Cons
- Cost: More expensive than traditional batt insulation.
- Flammability: Requires a layer of fire-resistant material for safety.
- Rigid: Not suitable for irregular spaces or areas with many obstructions.
- Environmental Impact: Manufacturing processes can be less environmentally friendly.
5. Reflective or Radiant Barrier Insulation
Reflective or radiant barrier insulation consists of a reflective film, usually aluminum, attached to a substrate like kraft paper or plastic film. It is installed in attics, primarily to reduce heat gain.
Pros
- Effective in Hot Climates: Reduces heat gain, making it ideal for warmer climates.
- Lightweight: Easy to handle and install.
- Energy Efficient: Lowers cooling costs by reflecting radiant heat away from the attic.
- Non-Toxic: Safe to handle and does not emit harmful chemicals.
Cons
- Limited Use: Less effective in cooler climates where heating is a primary concern.
- Dust Accumulation: Effectiveness can be reduced if the reflective surface gets dirty.
- Requires Air Gap: Needs an air gap to function correctly, complicating installation.
- Does Not Insulate: Does not provide thermal insulation, only radiant heat reflection.
6. Cotton (Denim) Insulation
Cotton insulation, often made from recycled denim, is an eco-friendly option for attic insulation. It is manufactured by shredding and treating denim fibers, which are then formed into batts.
Pros
- Eco-Friendly: Made from recycled materials, reducing environmental impact.
- Non-Irritating: Safe to handle without causing skin irritation.
- Sound Absorption: Provides good sound insulation properties.
- Fire-Resistant: Treated with borate for fire resistance and pest control.
Cons
- Cost: More expensive than traditional fiberglass batt insulation.
- Availability: Not as widely available as other insulation materials.
- Moisture Absorption: Can absorb moisture, leading to potential mold issues.
- Lower R-Value: Generally has a lower R-value compared to other insulation types.
7. Mineral Wool Insulation
Mineral wool insulation, also known as rock wool or slag wool, is made from molten rock or industrial waste. It is spun into fibers and formed into batts or loose-fill insulation.
Pros
- Fire-Resistant: Non-combustible and can withstand high temperatures.
- Soundproofing: Excellent sound insulation properties.
- Water-Resistant: Does not absorb water, reducing the risk of mold growth.
- High R-Value: Provides good thermal insulation.
Cons
- Cost: More expensive than fiberglass insulation.
- Installation: Heavier and more challenging to install.
- Availability: Not as readily available as other types of insulation.
- Dust: Can produce dust during installation, requiring protective gear.
Get the Proper Insulation for Your Home
Choosing the best insulation for your attic depends on various factors, including your climate, budget, energy efficiency goals, and other specific needs. From cost-effective batt insulation to high-performance spray foam, each type has its pros and cons.
If you’re looking for further guidance on selecting and installing insulation for your attic, connect with First American Roofing & Siding. Our experts are here to help you make an informed decision and ensure your home is energy-efficient and comfortable year-round.
Frequently Asked Questions
Should I Remove Old Attic Insulation Before Adding New?
Removing old attic insulation isn’t always necessary unless it’s damaged, moldy, or contains pests. If it’s in good condition, you can add new insulation on top. However, removal may improve energy efficiency and air quality. Consult a professional to assess your attic’s specific needs before proceeding.
Can I Put Too Much Insulation In My Attic?
Yes, too much insulation can reduce ventilation, cause moisture buildup, and lead to mold or structural damage. It may also compress existing insulation, reducing its effectiveness. Aim for the recommended R-value for your climate zone to balance efficiency and ventilation. Always consult a professional for guidance.
How Often Should Attic Insulation Be Replaced?
Attic insulation should be replaced every 15–20 years or sooner if it’s damaged, moldy, or infested by pests. Regular inspections can help identify issues like moisture or compression. Upgrading insulation when it underperforms improves energy efficiency and home comfort. Consult a professional for an accurate assessment.
Is It Okay To Cover Attic Insulation With Plywood?
Yes, you can cover attic insulation with plywood, but ensure it doesn’t compress the insulation, as this reduces effectiveness. Maintain proper ventilation and avoid blocking vents. Use spacers or elevated flooring systems to preserve insulation depth while creating storage space. Always prioritize safety and energy efficiency.
Where Should You Not Put Insulation In Your Attic?
Avoid placing insulation over attic vents, eaves, or around recessed lighting without proper barriers, as it can block airflow or create fire hazards. Don’t insulate directly under the roof sheathing, which can trap moisture. Ensure proper ventilation to prevent issues like mold or reduced energy efficiency.
