Denim insulation, also known as recycled cotton insulation, is becoming an increasingly popular option for eco-friendly home insulation. Made from recycled denim fabrics, such as old jeans, denim insulation offers some advantages over traditional fiberglass batt insulation. However, there are also some potential downsides to consider before installing denim insulation in your home. This article will examine the pros and cons of using denim insulation to help you decide if it is the right insulation choice for your needs.
What is Denim Insulation?
Denim insulation is a natural fiber insulation material made from recycled cotton scraps, specifically recycled denim fabrics. The most common source of the recycled cotton is old, discarded denim jeans. The denim is processed to remove any buttons, zippers, or seams, then shredded into fluffy insulation material.
Some key facts about denim insulation:
- Made from 85-95% recycled post-consumer denim scraps
- Remaining 5-15% is fire-resistant recycled fibers like polyester
- Manufactured into batts, rolls, loose-fill, or rigid boards
- Alternative to traditional fiberglass and plastic foam insulation
- Promoted as an eco-friendly, sustainable insulation option
- Becoming popular for sound insulation and thermal insulation
The recycled denim is treated with borate-based fire retardant chemicals so that the finished insulation meets fire safety codes. The fibers are held together with a small amount of low-VOC binder. This gives denim insulation its characteristic fluffy, cottony texture.
Denim insulation batts or rolls can be installed between wall studs, under floors, or in attics, just like fiberglass insulation. It can also be blown into cavities or spaces as a loose-fill insulation. Denim rigid boards are used for specialized applications like exterior insulation.
Pros of Using Denim Insulation
There are several advantages that make denim insulation an appealing green alternative to traditional insulation materials:
Renewable and Recycled Material
One of the biggest benefits of denim insulation is that it takes waste materials – old denim jeans that would otherwise go to landfills – and repurposes them into a useful insulation product. Most denim insulation contains 85-95% recycled post-consumer cotton content. This gives it an extremely low embodied energy and carbon footprint compared to synthetic insulations made from plastics or mineral fibers. The recycled denim reduces landfill waste, which is better for the environment.
Good Thermal Insulation Properties
Tests show that denim insulation provides similar or sometimes marginally better insulation R-value compared to fiberglass batt insulation. Denim insulation typically has an R-value between R-3.4 to R-4.3 per inch. This makes it suitable to use in walls, floors, ceilings and attics as thermal insulation. The densely packed cotton fibers resist conducted heat flow effectively.
Good Sound Absorption
In addition to its ability to insulate against heat flow, denim insulation also provides very good sound absorption and sound transmission reduction. The many air pockets within the fluffy recycled fibers can effectively absorb sound energy and dampen noise. Using denim insulation in interior walls can help reduce indoor noise levels.
Non-Itchy/Skin-Friendly
Denim insulation does not contain fiberglass fibers, so it does not have the same itchy and abrasive properties of fiberglass insulation. The soft, fluffy cotton fibers are generally more comfortable to handle and install without gloves or other skin protection. This also makes denim insulation ideal for exposed applications like interior insulating panels or acoustic wall panels, where appearance and touch feel are considerations.
Safer Indoor Air Quality
Compared to some other insulations, denim insulation made from natural cotton is less likely to emit VOCs (volatile organic compounds) that can degrade indoor air quality. Cotton is naturally mildew-resistant as well. The binders used in denim insulation are typically low-VOC type adhesives. And the fire-retardant borates used are non-toxic. So denim insulation generally scores higher on indoor air quality measures versus synthetic insulations.
Can Be Recycled/Composted
One of the perks of an all-natural cotton insulation like denim is that it can be recycled again or safely composted once its usable life is over. Synthetic insulations end up in landfills. But denim insulation batts can be reclaimed and reused if undamaged. Composting also allows its components to fully biodegrade at end-of-life.
Cons of Using Denim Insulation
However, denim insulation also comes with some potential disadvantages and downsides to consider:
Lower R-value Per Inch Than Fiberglass
The main thermal performance disadvantage of denim insulation is that it provides a lower R-value per inch compared to most fiberglass and plastic foam insulations. To achieve the same insulation value as an R-13 fiberglass batt, a denim batt would have to be almost twice as thick and fill more cavity space. A thicker insulation layer is needed to provide adequate thermal resistance.
Vulnerable to Moisture
Like any natural fiber, cotton insulation performs best when kept dry. It tends to absorb and retain moisture readily. Damp cotton insulation will feel cool and clammy and loses some of its insulating value. Cotton can also potentially support mold growth if exposed to excess moisture. Careful moisture control and vapor barriers are necessary when installing denim insulation. Wet denim insulation may need replacement.
Requires Fire Retardant Treatment
Pure untreated cotton is flammable at relatively low ignition temperatures. So denim insulation must be treated with chemical fire retardants to meet building code safety standards. However, the fire-retardant borates used do not tend to off-gas. And the overall fire-resistance is still better than for synthetic petroleum-based insulations.
Density Can Settle Over Time
One complaint with loose-fill denim insulation used for blown-in attic insulation is that the dense cotton fibers tend to settle towards the bottom over the first few years. This takes away some insulation value. Routine inspection and re-fluffing may help restore uniformity. Heavier dense-pack blown denim may avoid this issue.
Potential Allergen Concerns
Like other natural fiber insulation, denim insulation is not immune to potentially forming dust that can trigger allergies or asthma in sensitive persons. However, denim insulation receives high marks for having minimal off-gassing and fiber release if properly encapsulated.
Supply Availability Issues
Denim insulation is not yet produced in the same high volumes as traditional insulation. So it may be harder to source or have long lead times compared to readily available fiberglass. There are only a handful of manufacturers, with limited distribution networks in some regions. Lead times for ordering and shipping denim insulation are usually higher.
Can Be More Expensive Than Fiberglass
Due to its relative rarity and niche status currently, denim insulation tends to cost 20-30% more per square foot than common fiberglass batts. However, for a committed eco-friendly homebuilder, the sustainability benefits of recycled cotton insulation may warrant the pricing premium. Costs may also decline in future if it gains broader adoption.
When is Denim Insulation a Good Option?
Here are some of the situations where using denim insulation can be advantageous:
Eco-Friendly Construction Projects
For green builders and eco-conscious homeowners who want to use recycled and natural building materials whenever possible, denim insulation is an obvious go-to choice to replace synthetic insulations. It appeals to sustainability-focused projects.
Noise Control Applications
The excellent sound dampening properties of denim insulation make it an ideal choice where noise control is the primary goal. Use for interior partitions, theater rooms, studios, or to wrap noisy ductwork and pipes.
Exposed Insulation Areas
Since it is more aesthetically pleasing and comfortable than irritating fiberglass, recycled denim insulation works very well for exposed insulating applications like basement foundation walls, unfinished attics, covered radiators or ducts, cathedral ceilings, etc.
Homes with Vapor Barriers
In locations like unconditioned crawlspaces and basements where a vapor barrier is recommended anyway, denim insulation performs fine because it is protected from dampness issues.
Cold Climate New Construction
Well-sealed new homes in dry colder climates can effectively use denim insulation, with good moisture control and containment. The installation quality is key here.
Retrofits Requiring Non-Itchy Insulation
When retrofitting insulation in tight spaces in occupied existing homes, ultra-soft denim insulation is easier to work with versus ‘itchy’ fiberglass.
When is Denim Insulation Not Ideal?
Here are some situations where denim insulation may not be the right choice:
Pre-1930s Homes Lacking Vapor Barriers
Older homes with damp crawlspaces, inadequate vapor barriers, and questionable envelope sealing are probably too risky for moisture-sensitive denim insulation. Stick with moisture-resistant fiberglass here.
Hot Humid Climates
In southern regions with hot, humid summers and abundant rainfall and dampness, moisture control is already challenging. Here, synthetic insulations or closed-cell foams may be better able to withstand moisture issues.
Budget-Driven Projects
If keeping insulation costs to an absolute minimum is the priority, rather than eco-friendly aspects, then cheaper fiberglass would make more economic sense over pricier denim insulation.
Timelines Requiring Quick Insulation Delivery
Due to supply chain limitations currently, denim insulation may not be the best match where the construction timeline requires immediate insulation material delivery with no flexibility. Lead times may not work.
Inaccessible Insulation Locations
For certain crammed insulation sites where available space is ultra-tight, fiberglass or spray foam may fit the fixed cavity depth better, since less thick denim would be needed to match their R-value.
Key Considerations When Using Denim Insulation
Here are some tips to get the best performance from denim insulation and manage any potential drawbacks:
- Carefully follow the manufacturer instructions for proper installation and containment.
- Pay close attention to attic ventilation and crawlspace moisture barriers when using denim insulation.
- In damp basements, combine denim insulation with vapor barrier enclosures or closed-cell foam.
- Have a long-term maintenance plan to monitor settled attic insulation and re-fluff/redistribute as needed.
- Wear basic skin and respiratory protection during handling and installation.
- Use denim insulation alongside other ‘green’ building materials and moisture control systems.
- Seek professional advice to estimate the required thickness of denim insulation to achieve your target insulation R-values.
- For building codes, you may need an affidavit or additional documentation to prove the fire-resistance of denim insulation.
Top Denim Insulation Brands
Here are some of the leading manufacturers and brands of recycled denim insulation products:
Bonded Logic – UltraTouch Denim Insulation batts, loose-fill, and rigid boards. Largest denim insulation producer.
Insultex – Insul-Denim insulation batts and alternative to fiberglass rolls.
US GreenFiber – GreenFiber blown-in loose-fill insulation from recycled denim and paper.
IVR Industries – Winco Batts recycled denim insulation batts.
Heartland Denim – Blue73 loose-fill insulation made from recycled denim.
The Bottom Line
Denim insulation made from recycled denim offers excellent sustainability benefits and appeals for green building. It diverts old jeans from landfills and repurposes them into quality insulation. Cotton insulation also delivers great noise reduction and comfortable handling compared to itchy fiberglass.
However, the lower R-value per inch means it takes thicker denim insulation to achieve required thermal insulation levels. Denim insulation also requires proper moisture protection. Overall, denim insulation works best when intelligently installed for energy-efficient homes in controlled conditions, especially for soundproofing needs or eco-friendly projects. With the right climate and installation considerations, the advantages of recycled denim insulation can outweigh its limitations.
Frequently Asked Questions About Denim Insulation
Can denim insulation get wet?
Denim insulation can get wet and absorb moisture. This temporarily reduces its insulation value. Wet denim insulation also runs the risk of encouraging mold growth. So it is very important to keep denim insulation properly enclosed and dry using vapor barriers or encapsulation.
Is denim insulation better than fiberglass?
Denim and fiberglass insulations have different strengths and weaknesses, so it depends on your needs and priorities. Denim insulation provides better sound absorption and is more comfortable to handle. Fiberglass has higher R-value per inch and lower cost on its side.
How long does denim insulation last?
With adequate moisture control, properly installed denim insulation should last for decades of use just like traditional insulations. Denim insulation does not degrade or lose effectiveness over time. Containment and ventilation are the keys to longevity.
Can you put denim insulation in the attic?
Yes, denim insulation works very well for open, unfinished attic spaces when installed correctly between the joists and with good attic ventilation. It provides great thermal and sound insulation for well-ventilated attics. Just be sure to provide moisture barriers.
Is denim insulation safe for babies?
Denim insulation made from natural fibers does not have the same respiratory risks and itchiness concerns often associated with fiberglass insulation around babies. But always ensure proper dust containment just as you would for any attic insulation by sealing and encapsulating it.
Conclusion
Denim insulation made from recycled denim jeans offers benefits like sustainability, sound absorption, comfort, and indoor air quality. But moisture vulnerability, lower R-value per inch, and supply limitations are some factors to also weigh when comparing to traditional fiberglass. With its unique pros and cons in mind, denim insulation can be an excellent eco-friendly insulation choice for the right applications. Proper installation and containment are key to maximizing benefits while avoiding potential moisture issues. Overall, denim insulation provides a renewable, comfortable, and effective insulation option for modern green buildings.