Cellulose insulation represents a plant fiber used in roof and wall cavities to insulate, reduce noise and as a draught proof. It is a low-thermal-conductivity material used to reduce noise transmission and to reduce heat loss and heat gain in buildings. Cellulose is one of the old types of building material that have been in use for many centuries (Morelock). Several types of cellulosic materials used in buildings include the corncob, newspaper, straw, sawdust, hemp, cotton, and cardboard. The ancient Monticello was insulated with some form of cellulose.
The modern cellulose insulation began in the 1950s where the cellulose building material was made of recycled newspaper using dust removing and grinding machines with addition of fire retardant. The adoption of cellulose building material in the US came into general use during the 1970s. The demand for insulation increased significantly following the oil embargo of 1973-74 (Dwyer). The energy cost for heating spiraled across the nation after the embargo which resulted in an increased interest to adopt energy conservation measures. Thus, the need for insulation gained substantial national attention since it was the only cheap and available technology to improve the energy efficiency of homes. For instance, in 1977, a tax credit was offered to homeowners who managed to install the insulation during a severe winter period.
The number of cellulose insulation firms’ has risen in the United States from 125 plants in 1976 to more than 500 plants in 1978. Cellulose insulation material was made locally by small producers who procured ready-to-operate machines and provided an easy and a cheap, low-tech production process. Besides few constraints at the time such as the scarcity of boric acid for use as a fire retardant, on the other hand, the material attracted an increased share of the market owing to its suitability for retrofits and lower costs.
Cellulose insulation is often used as a smart alternative to fiberglass. It offers an affordable, green, non-toxic and efficient thermal solution that is worth considering. As a thermal protection, cellulose material is essential for homes for provision of comfort, controlling the durability and the cost of operation. Though fiberglass insulation has been widely used in the United States particularly the new homes due to its bearer standards qualities, the homeowners are presented with a range of other insulation options such as the rock wool, plastic foams, cotton and cellulose insulation which are also readily available (Dwyer). These materials come in several forms, for instance, some insulation materials are laid, stapled, sprayed, blown or nailed in place. Despite these different options which can be hard to sift, cellulose insulation material stands out as a strong contender.
R-value is the predominant standard for which insulation is measured; this standard is often used to measure the level of resistance to heat flow. It is used to measure conductive resistance- the capacity of a material to prevent the flow of heat along the uninterrupted chain of matter that makes up a solid material. The heat within homes is typically lost through conduction. Usually the cellulose insulation material is adopted to prevent heat loss. Just like the other insulation materials, cellulose gives an R-value of about R-3.5 per inch of thickness. The material blocks air flow outside the building impeding in the process air leakage that occurs through gaps, cracks and voids that is responsible for approximately one-third of an average heat loss in homes. The quality of tightly packed cellulose material is known for its high insulation power and thermally efficient solution.
The cellulose insulation material is ‘green.’ It is made of eighty percent post-consumer recycled newsprint. Its fiber is treated with non-toxic borate compounds (twenty percent by weight) to resist mold, fire, and insects. According to the Cellulose Insulation Manufacturers Association (CIMA) insulating a fifteen thousand feet house with cellulose will manage to recycle as much newspaper as an individual will consume in forty years (Dwyer). It is estimated that if new homes are insulated with cellulose it will remove three million two hundred thousand tons of newsprint from the nation’s waste stream every year.
According to current construction statistics, fewer homes about ten percent use cellulose building material. Unlike fiberglass, cellulose requires less energy to manufacture, and this makes it earns the name ‘green’ insulator material. Approximately eight times more energy is required to manufacture the same amount of fiberglass in comparison to the energy cost per installed R-value unit. The reduced production energy makes cellulose the best insulator in the market.
Cellulose is made of paper which makes it the safest building material. It is treated with chemicals to make it a permanent fire resistance substance. Fiberglass industry has generated static suggestion that cellulose material could burn, but according to independent testing cellulose has been found to be safe and approved by all building codes (Morelock). Many construction experts consider cellulose building material as more fire-proof than fiberglass because its cellulose fibers are packed tightly preventing in the process the spread of fire through framing cavities by effectively chocking wall cavities of combustion air.
Incorporating wet insulation in buildings of any kind is ineffective. Cellulose material does not exhibit wet features since it is hygroscopic and thus able to hold and soak liquid water. During construction, cellulose should be installed properly to prevent undetected leaks that may wet the material causing it to sag within the framing cavities. The wet conditions brought about by the water leaks compresses the blanket of fiber and under severe situations; it can create a void space that lowers its thermal value.
Another major concern involves the chemical used to inhibit cellulose from a fire that has the potential to become corrosive in wet environments (Dwyer). For example, the tests undertaken by the Oak Ridge National Laboratory indicated that chemical treatments applied to treat cellulose might cause the corrosion of electrical wires, metal fasteners, and plumbing pipes when they are left in contact with wet treated cellulose insulation materials for long periods of time.
Essentially it has been found out that cellulose material offers a better R-value when compared with fiberglass. Its technical features make cellulose a better insulation material as it gives greater resistance to air leakage (Parker). Tightly packed well cellulose is known to offer substantial insulation than any other insulation material. Its cellular structure and wood fiber are naturally more resistant to heat conduction especially when air-barrier systems are not perfectly installed.
Apart from providing thermal protection, cellulose is an appropriate material to fit around items in walls such as wiring and pipes leaving minimal air pockets that can lower the overall efficiency of the wall. Tightly packed cellulose has increased capacity to seal walls from air infiltration while giving the density to reduce convection when placed appropriately. According to a study conducted by The University of Colorado School of Architecture and Planning to compare identical test structures insulated with fiberglass and the other with cellulose, indicated that cellulose insulation material tighten the structure thirty percent more than the building structure insulated with fiberglass (Parker).
Cellulose material also serves as a sound insulator. It lowers the sound traveling through floors and between walls levels. Because of its damping and mass features, cellulose reduces noise in two ways, first it attenuates the passage of sound along cavities, and secondly it lowers the lateral movement of sheetrock. It is estimated that cellulose is three times denser compared to fiberglass thus makes it exhibit slight improvement in sound reduction.
Cellulose is also used within the internal settings of buildings to control mold. The buildings insulated with cellulose have shown higher resistance to mold even when the building undergoes through many months of water saturation. This feature is attributed to borates chemicals used to treat the material (Parker). The chemical used helps control pest attack on the walls of the building. The presence of boric acid kills the insects when the self-grooming insects ingest the chemicals. The cellulose material should be treated with sufficient concentration to make it effective and thus ensure that high insect fatality is achieved.
Cellulose acts as a good vapor barrier since it fills the wall cavity completely. Apart from preventing the moisture problems cellulose also distributes moisture evenly throughout the cavity thus suppressing the accumulation of moisture in one area and aids to dry the moisture more quickly.
Insulating buildings with cellulose makes the buildings becomes energy-efficient and thus lowers energy emission to the environment (Morelock). Besides during the manufacture of cellulose the energy used is considerably lower compared to other insulator materials such fiberglass hence minimal amount of energy is released to the surrounding. The reduced amount of energy during production qualifies the material to be regarded as ‘greener’ insulator.
Cellulose as an insulator helps recycle content that otherwise would have polluted the environment. The materials such as newspapers and sawdust that could have been dumped into landfills are excellently recycled into high-quality end insulator materials. Cellulose is made up of eighty-five percent of the recycled paper fiber that is often the post-consumer waste newsprint (Morelock). As compared to fiberglass insulators that have a maximum recycled content of fifty percent; cellulose has the highest recycled content making it more environmentally friendly than any available the insulator.
Cellulose is produced and used locally which makes the materials easily accessible and thus requires shorter shipping distances reducing in the process the resulting fuel emissions. Usually when the shipping distance from the industries to the consumer are long the fuel emissions of the ships and vehicles used to transport the product negatively impact the environment. Therefore, cellulose is an efficient environmentally friendly insulator that should be widely adopted.
Dwyer, Nathan P. “Cellulose Insulation Tests.” Fire Findings. (2007). Print.
Morelock, Jamie C. “Overhauling When Cellulose Insulation Is Present.” Fire Engineering.
Parker, Philip M. The 2007-2012 World Outlook for Cellulose Insulation. ICON Group, 2006.