Why Cellulose?

Check out the video to see the benefits of cellulose, including the impact our product has on the environment, courtesy of Producer Member Advanced Fiber Technology.

Environmental Impact

When it comes to protecting the environment, no other building insulation comes close:

Cellulose insulation is made from up to 85% recycled paper and cardboard—higher than almost any other commonly used building material. Other elements in cellulose insulation include chemicals like boric acid, which is used here as an insecticide and flame retardant, but found in everything from industrial to agricultural to medical products.

Cellulose insulation has the lowest embodied energy, or the amount of energy used in the manufacturing process, of the leading insulation products.

The shipping distance from the factory to the consumer impacts the environment. Cellulose insulation is produced regionally and has generally shorter shipping distances, lowering resulting fuel emissions.

Having a renewable natural resource for the raw material influences the environmental aspects of the product. Cellulose insulation is made from consumer paper products, which are tied to responsible forestry management and a highly renewable resource of planted trees

Most construction projects have large dumpsters on site full of construction waste and debris from building products that end up in the waste stream and require shipping to landfills, further impacting the environment. Cellulose insulation is fully recovered and reused on-site when installed by professional insulation contractors, leaving virtually no excess material to return to the waste stream. Special machines used in the blown-in process allow excess or over spayed material to be vacuumed up and be blown back in on site or salvaged for a future installation.

A building product that can sequester carbon has a huge benefit to the environment by reducing greenhouse gasses that cause climate change. Cellulose insulation is basically plant cell matter in the form of paper that is made from wood and thus contains high percentages of carbon. When added to homes, as part of wood-intensive construction, cellulose insulation traps that carbon for years effectively lowering the carbon footprint of homes.

Read our report, The Carbon Story of Cellulose Insulation here.

To view the industry’s Environmental Products Declaration (EPD), click here.

Thermal Performance

Whether you live in a region that sees snow five months out of the year or you have sunshine over 300 days a year, everyone should use insulation. Why? Insulation slows the transfer of heat leaving AND entering homes.
Air infiltration and exfiltration has a major impact on the R-Value – the thermal resistance – that insulation delivers and, as a result, on the thermal performance of an insulated dwelling.
So how can you help prevent that? By putting high-density insulation in your attic and wall cavities. Dense insulation inhibits movement of air from warm to cold (interior to exterior) in winter and cold to warm (exterior to interior) in summer. The higher the density of the material, the better it is at inhibiting the movement of air. Both cellulose and closed-cell foam insulations have a much higher density than fiberglass, so both potentially are more efficient at inhibiting air movement. CIMA recommends air sealing the gaps around electrical boxes, plumbing, windows, and other areas within the house. Then install cellulose insulation according to the coverage chart of the manufacturer, available on the bag and the manufacturer’s website.
Putting forth the cost to better insulate your home now will translate to decades of savings on your energy bills.

Sound Benefits

Cellulose insulation is widely used to help limit exterior noise intrusions as well as noise between rooms.

Noise Reduction Coefficient (NRC)

Noise Reduction Coefficient measures the build-up of noise within a space. A NRC number index rating is used to measure the sound absorption quality of a material. Cellulose products have an NRC rating that can range upwards of .80 or higher depending on the product, and the wall, floor, or ceiling design where the material is installed. What this means is cellulose insulation can absorb 80% or more of the sound it comes into contact with.

Sound Transmission Class (STC)

Sound Transmission Class measures the sound transmission between spaces. A single number rating is used to measure a structure’s ability to impede sound transfer. The higher the STC rating, the more effectively a wall, floor, or ceiling controls sound transmission. Noises can be heard through a wall with an STC rating of 30 but should be much less audible through a wall with a rating of 60. Cellulose insulation may be used to achieve STC ratings as high as 70 depending on the wall or partition assembly where the product is installed.

Fire Protection

All cellulose insulation is treated with fire retardants to meet federal, state/province, and local fire safety requirements.
The US Consumer Product Safety Commission (CPSC) established the fire safety requirements for cellulose insulation in 1978. Cellulose insulation is one of very few building materials that always contain fire retardants. Lumber, sheathing, kraft-faced fiberglass batts, asphalt-based roofing materials, carpet, etc. are typically not treated with fire retardants. Across the range of cellulose insulation manufacturers, the chemicals added provide an effective one-hour fire rating. The addition of these chemicals will slow the spread of a fire, allowing you more time to escape any danger.
The term “flame spread” refers to the speed at which flames “spread” along the surface of the insulating material. “Smoke developed” refers to the amount of smoke that is produced while the product burns. In most house fires, it is not the flames which cause serious personal injury, but rather smoke inhalation. Smoke also increases confusion during a crisis and obscures important fire exits. The building codes establish a maximum flame spread of 25 and smoke developed index of 450 as tested under ASTM E84.
When properly installed, cellulose insulation can help reduce the spread of flames in house and building fires. Some manufacturers have even qualified two- and three-hour firewall designs using cellulose insulation.

Mold & Moisture

Moisture moves by four different transport mechanisms: (1) bulk water movement (rain, snow, or groundwater); (2) capillary action (capillarity); (3) air movement; and (4) vapor diffusion. Of these mechanisms, air movement is the primary cause for moisture-related issues in buildings. Cellulose insulation impedes the movement of air generated by wind, stack effect, and mechanical imbalances within buildings. By hindering the movement of moisture-laden air, cellulose reduces moisture movement to manageable levels within the building assemblies. Any remaining moisture moving by diffusion will be further blocked by primers and paints used on the interior surfaces.
The hygroscopic nature of cellulose insulation allows it to manage and wick moisture from areas of greater to lesser concentrations, thus preventing damaging amounts of moisture from accumulating. This is a key distinction between cellulose and other types of insulation and an important benefit for homeowners when making insulation decisions.
Note: Many building codes require an air barrier and/or vapor barrier be installed. Check with your local officials regarding compliance.

Product Installation

Whether a new build or an old house, cellulose insulation can be installed in any type of home. When installing cellulose in an attic or ceiling, follow the directions on the manufacturer’s bag and/or website, ensuring proper ventilation and care. For wall retrofits, CIMA takes the stance that installation of cellulose should be left to the professionals. The typical age of these homes makes for substantial liability. Knob and tube wiring, balloon framing, building cavities used as HVAC ducts, and combustion appliance air volume are some big issues that homeowners could run into without knowing how to handle properly.

Want to see installation of cellulose in new construction or retrofit of an existing home? Click the videos below to see examples.

New construction, courtesy of Producer Member Soprema

Retrofit installation – dense-packed cellulose in an existing home

Tax Incentives

For potential savings opportunities in the form of tax credits and similar incentives from the U.S. Department of Energy, the DSIRE website database lists incentive programs for many state and local programs around the nation. Natural Resources Canada has a Directory of Energy Efficiency Programs for Homes that includes federal and provincial incentives. Also check with your local utility company about insulation savings programs that may not be listed elsewhere.

Myths & FAQ

How much insulation should I install?

Each area of the country has different recommended R-values for insulation. Use the regional R-Value map to find out the recommended R-values for your area in the US and Canada and use our insulation calculator to get an idea of your potential savings. CIMA member Applegate Greenfiber also has a video to determine how much product you will need.

Do I have to remove the insulation that is already there?

Not necessarily. Adding more insulation has a cumulative impact on the overall R-value. In attics, If the insulation is damaged or improperly installed, in the case of batt products, it might make sense to replace it completely with blown-in cellulose insulation. You can also add cellulose insulation on top of the existing insulation, improving the overall quality and R-value. In walls, it is possible for contractors to install additional insulation so it compresses the existing material, completely filling the wall cavity with performance enhancing cellulose insulation.

What does R-value mean?

R-value is a measure of resistance to heat flow through a given thickness of material. The higher the R-value, the greater the resistance. As explained above (link to thermal benefits), resisting heat flow is the primary purpose of insulating, which in turn lowers energy costs.

Does cellulose insulation cause skin irritation?

No. Cellulose insulation does not contain any glass fibers, such as those found in fiberglass insulation, that cause skin and respiratory irritation.

I just put cellulose insulation in my home. Why does it feel damp?

The natural moisture content of cellulose insulation is 8-12%. Even at 30%, which is the usual moisture content of wall spray immediately after application, you probably couldn’t tell there was any added moisture, unless someone told you. If the insulation is in fact wet, it is because of a water incursion from a roof leak, a pipe leak, condensation on a cold surface, or water entering your attic through a vent. In that case, it would be necessary to find the source of the water incursion and make an appropriate repair. Assuming that the insulation isn’t water-saturated it will dry to the 8-12% range within a few weeks, if not a few days.

Do I need any special equipment for cellulose insulation DIY projects?

Yes. Cellulose insulation is compressively packaged, so it must be installed with a blowing machine, which can be rented or sometimes borrowed from many home improvement stores, lumber yards, or tool rental centers. As with most home improvement projects, it is recommended that you wear protective gear such as a mask and eye protection during the installation process.

How do I know the R-value of my current insulation?

Every product has a different R-value, so make sure you read the packaging carefully. As a rule of thumb, if you have six inches or less in the attic (or the insulation does not cover the joists), it would be smart to add more insulation. Use the regional R-Value map to find out the recommended R-values for your area in the US and Canada to determine the total R-value recommended. You can always add more insulation in the attic on top of the existing insulation to achieve even more energy savings and comfort.

The Canadian R-value map doesn’t look like the one for the United States. Help!

One big difference between the United States and Canada is that the Canadian requirements are based on effective thermal performance and are expressed in U-values instead of R-values (overall thermal transmittance, as opposed to resistance). Effective thermal performance requires to take into account all materials in a roof or wall assembly, including thermal bridges generated by studs, floor slabs, balconies, window-to-wall transitions, etc. The R-value of insulation needed to meet code will be dependent on the design.

The NECB is a model code. It is a provincial/territorial responsibility to adopt the code or adapt it in some way. Some provinces or territories adopt NECB directly (each at their own enforcement date). Some provinces (British Columbia and Ontario, for example) publish their own energy code or bulletin.

Some provinces have requirements that differ by construction type. In most cases, low-rise residential (referred to as “housing and small buildings” in most codes) have a set of requirements and all other building types (commercial, institutional, industrial) have a different set of requirements.

Do I need a vapor retarder?

With cellulose insulation, a vapor barrier isn’t recommended in the United States except in cases of high humidity areas, such as pools and spas, or in extremely cold climate zones, usually 9,000 HDD or more. Canadian building codes generally require use of a vapor barrier. What is the best insulation to use in a cold climate? Studies by Oak Ridge National Laboratory show that the performance of cellulose insulation remains stable even at very cold temperatures, thus making it one of the best choices for insulating homes in colder climate.

Where can I get cellulose insulation if I want to do it myself?

Cellulose insulation is available at many home improvement stores and lumber yards. Some stores also rent machines for installation and can help with any insulation questions you might have.

If cellulose is made from recycled paper products, wouldn’t that decompose over time?

Pursuant to the National Association of Home Builders (2007) Study of Life Expectancy of Household Components, “As long as they are not punctured, cut, or burned and are kept dry and away from UV rays, the cellulose, fiberglass, and foam used in insulation materials will last a lifetime. This is true whether the insulation was applied as loose fill, house wrap, or batts/rolls.”