Is denim insulation better than fiberglass?

Insulation is a key component of energy efficiency in homes and buildings. Good insulation helps maintain indoor temperatures while reducing energy costs. Two popular types of insulation are denim insulation and traditional fiberglass. But which one is better? Here is an in-depth comparison of denim vs fiberglass insulation.

What is Denim Insulation?

Denim insulation is a relatively new type of insulation made from recycled cotton denim. It is produced by shredding old denim clothing, such as jeans, into fibers and treating it with fire retardant chemicals. The end product is a fluffy blue insulation material reminiscent of cotton candy.

Denim insulation offers several potential advantages over traditional fiberglass:

• Made from recycled materials, giving it eco-friendly appeal
• Does not irritate skin or cause itching/sneezing like fiberglass
• Can be installed without gloves, mask, or other safety gear
• Can be re-used if removed and re-installed in another location

The manufacture of denim insulation also helps divert waste from landfills. It provides a use for old clothing that may otherwise be discarded.

How is Denim Insulation Made?

Denim insulation is produced through a multi-step manufacturing process:

1. Old denim clothing is collected from recycling programs, thrift stores, textile factories, etc.
2. The clothing is sorted by color and shredded into fibers.
3. Cotton fibers are separated from zippers, buttons, and other non-cotton materials.
4. The denim fibers are conditioned with natural fibers and binding agents.
5. Fire retardant chemicals are added for safety.
6. The treated fibers are formed into batts or rolls of insulation.

By recycling old clothing that would otherwise end up in landfills, denim insulation gives new life to waste materials. The final product is a safe, environmentally-responsible insulation.

Pros and Cons of Denim Insulation

Here is a quick overview of the advantages and disadvantages of using denim insulation:

Pros:

• Made from recycled materials
• Does not irritate skin or respiratory system
• No safety gear needed for installation
• Can be reused if removed from a building
• Good acoustic insulation
• Resistant to mold, mildew, and pests

Cons:

• Typically more expensive than fiberglass
• Lower R-value per inch than fiberglass
• Denser and heavier than fiberglass
• May require thicker insulation to achieve desired R-value
• Availability limited in some regions

While denim has advantages related to comfort and environmental impact, it also has some limitations regarding performance and cost. The pros and cons should be carefully weighed for each specific insulation project.

How Effective is Denim Insulation?

The effectiveness of insulation is measured by its R-value. The higher the R-value, the better the insulating performance. Denim insulation typically has an R-value between 3.5-4 per inch. This compares to a typical R-value of around 3-4 per inch for conventional fiberglass batt insulation.

Some key considerations regarding denim insulation effectiveness:

• Has a lower R-value per inch than most types of fiberglass insulation
• May require a thicker layer of insulation to achieve desired R-value
• Performance can vary among denim insulation products
• R-value declines when insulation gets wet
• Works best when installed properly without gaps or compressed areas

Many homes require R-13 to R-30 insulation in walls and attics. Due to its lower R-value per inch, denim insulation may need to be significantly thicker than fiberglass to achieve the recommended insulation levels.

How Much Does Denim Insulation Cost?

Denim insulation typically costs 2-3 times more than traditional fiberglass insulation per square foot:

Insulation Type	Cost per Square Foot*
Fiberglass batts	$0.50 – $1.50
Denim insulation	$1 – $4

*Cost ranges are approximate; actual prices may vary by region and supplier.

The higher cost of denim insulation is due to:

• Relatively low availability and high demand
• Higher manufacturing costs compared to fiberglass
• Lack of manufacturing scale economies currently
• Perceived as specialty green product that can command price premium

Homeowners should carefully calculate insulation needs and costs. The thicker denim required to match fiberglass R-value may partially offset its higher per-square-foot price.

What About Sound Insulation?

In addition to thermal insulation against heat/cold, denim also provides good acoustic insulation against sound. Several characteristics make denim effective for soundproofing:

• Made from dense, heavyweight cotton fibers
• No wrinkles or gaps, unlike some fiberglass installs
• Absorbs vibrations and dampens sound transmission

Denim insulation achieves a Sound Transmission Class (STC) rating of 39. This compares favorably to typical ratings of 28-32 for fiberglass insulation. The higher STC rating means denim blocks more noise.

Key takeaways on sound insulation:

• Denim provides good damping of noise and vibration
• Noticeably better acoustic insulation than fiberglass
• Ideal for interior walls, floors, and ceilings
• Can reduce unwanted sounds between rooms or floors

Home theaters, music rooms, and other areas where sound control is important can benefit from upgraded denim insulation.

Fire Safety and Toxicity

Both denim and fiberglass insulation are treated with fire retardant chemicals to meet building code safety standards. However, denim faces fewer health concerns related to toxicity:

• Fiberglass fibers can irritate skin, eyes, and respiratory system
• Tiny glass particles may be inhaled into lungs
• Special safety gear recommended when handling fiberglass
• Denim made from natural cotton, causes very little irritation
• No special equipment needed for DIY denim insulation

Denim also contains some boron-based fire retardants. But these are bonded within the cotton fibers, unlike loose fiberglass particles. Any health risks are low.

Mold and Mildew Resistance

Insulation in damp areas risks growing mold, mildew, and bacteria. Spores can then spread through the home causing allergic reactions or illness. Fiberglass and denim insulation have different vulnerabilities to microbial growth:

• Fiberglass insulation is inorganic so doesn’t directly support mold growth
• But fiberglass dust can trap moisture and provide food source for mold
• Starch binders used in some fiberglass also supply nutrients for microbes
• Denim insulation made from natural fibers risks mold growth when wet
• But denim contains zero food source, starving mold/mildew spores

Properly installed in dry areas, both types of insulation should resist microbial growth. Wet conditions favor denim since it lacks any food sources for mold or bacteria.

Environmental Impact

Eco-friendliness is a major advantage of denim insulation. Key environmental benefits include:

• Made from 95-99% recycled content
• Diverts old clothing from landfill waste
• Cotton is biodegradable and renewable
• No chemical emissions like formaldehyde with fiberglass
• Lower carbon footprint than manufacturing fiberglass

For homeowners concerned about environmental impact, denim insulation offers significant “green” credentials. The use of recycled materials and carbon-neutral manufacturing process makes denim insulation a more sustainable choice.

Workability and Installation

Ease of handling, cutting, and installation also differs between insulation types:

• Fiberglass is lighter and more flexible but can be irritating
• Denim is heavier but easier on skin and lungs
• Fiberglass requires long sleeves, gloves, and masks
• Denim insulation can be installed by homeowners with no special gear
• Both require adequate ventilation when working in attics or enclosed spaces

Many homeowners find denim insulation simpler to work with. But its heavier weight makes installation on overhead surfaces more challenging. Good DIY skills and physical fitness are beneficial when installing any insulation.

Availability and Code Compliance

While growing in popularity, denim insulation has less widespread availability compared to standard fiberglass. Factors affecting availability include:

• Fewer manufacturing facilities currently producing denim insulation
• Lower overall production volumes and inventory
• Mostly sold through specialty distributors rather than big box stores
• May not be carried by local building suppliers in some regions

Code approval may also be an issue in areas where denim insulation is less common. Be sure to consult local building codes before using denim insulation.

Resale Value Considerations

An upgrade to denim insulation improves energy efficiency and comfort. But how much does it impact resale value when selling a home?

• Green building features like recycled denim insulation are desired by some buyers
• Can potentially help a home sell faster in certain markets
• But harder to quantify added resale value vs standard insulation
• May only provide an advantage if homebuyer specifically values sustainability

In general, insulation is not a huge factor influencing home prices during resale. Location, schools, kitchens and bathrooms tend to be bigger drivers of value. Any resale benefit of denim insulation depends on the buyer.

Should I Choose Denim or Fiberglass Insulation?

So what’s the final verdict? Should you use eco-friendly denim or traditional fiberglass insulation? Here are key factors to consider when deciding:

• Budget – Fiberglass is cheaper; denim costs up to 3X more per square foot
• R-value – Denim may need to be 1.5 times thicker to achieve desired insulation R-value
• Toxicity – Fiberglass irritates skin and lungs; denim is safer to install
• Environmental impact – Denim made from recycled materials is greener
• Soundproofing – Denim blocks more noise transmission
• Availability – Fiberglass more widely available; denim supply still limited

Choosing the best insulation depends on your needs, budget, and project specifics. Denim insulation makes sense for green builders focused on eco-friendly and soundproofing properties. Fiberglass remains ideal where cost is the priority. Proper installation is also key to maximize insulation performance.

If you’re on the fence, get contractor quotes for both types of insulation and compare costs. A hybrid approach using traditional batts in less accessible areas along with denim insulation in walls and ceilings is another option. This balances cost, performance and environmental benefits.

The Bottom Line

Denim insulation has unique properties compared to fiberglass insulation:

• Made from recycled denim with eco-friendly appeal
• Does not irritate eyes or skin like fiberglass
• Provides better noise dampening and soundproofing
• More vulnerable to moisture and mold concerns
• Higher R-value per inch makes fiberglass more efficient
• Denim insulation remains pricier than traditional fiberglass

Choosing the right insulation involves tradeoffs between performance, cost, health factors, and environmental impact. Fiberglass works fine for basic insulation needs. Denim insulation offers upgrades in acoustics and sustainability. Determine what’s most important for your specific project when deciding between denim vs fiberglass batt insulation.