Fiberglass vs. Cellulose Insulation

Insulation of homes, shopping complexes, malls, schools, hospitals and buildings from fire, is an important concern for builders, architects and homeowners. Unwanted sound or noise, is also a major disturbance in populated urban areas, where the influx of heavy traffic creates sound pollution. Designing any house or building involves the consideration of the best products available, that provide insulation from fire and sound. Fiberglass and cellulose have been widely used for insulation. However, there has been an ongoing debate on the effectiveness of fiberglass and cellulose insulation. Health concerns, cost-effectiveness, durability and environmental benefits are the major issues that people generally consider before choosing either of these widely used insulators.

Fiberglass Insulation
Fiberglass is an artificial synthetic fiber that consists of calcium silicates, aluminum and other metals. The process of manufacturing fiberglass is called Pultrusion, that involves fabricating linear glass fibers. Fiberglass insulation has been used since 1930's. Today, Nearly 90% of North American homes use fiberglass insulation. The popularity of fiberglass insulation owes to the fact that it is cost-effective and helps the consumers to insulate their houses from excessive cold and heat. Fiberglass insulation is generally provided in forms of chopped fibers or sheets, and is yellow, pink or white.

Cellulose Insulation
Cellulose is basically glucose-tapped from recycled newspapers, magazines and cardboard which is treated with chemicals to produce an insulating material with varying properties. Cellulose insulation is installed in many forms like spray applied cellulose (wet-spray), stabilized cellulose and low dust cellulose. Fire resistant chemicals are added to cellulose to increase the efficacy. Earlier it was found that when cellulose insulation was applied to wooden pipes and furniture, it attracted rodents. However, nowadays addition of pesticides in the cellulose insulation has controlled this problem.

Fiberglass Vs. Cellulose Insulation
Choosing an insulator is not an easy task. One can consult reliable manufacturers and research, before choosing the insulator. The question which remains is, which insulator is better? Cellulose or Fiberglass. Let's take a look.

The Differentiating Factor: R-Value
Before installing any insulating material, the key is to check its R-value. R-value is a number usually printed on the insulating material, that is a measure of the ability of the material to conduct thermal heat. The higher the R-value of a substance, the better the thermal insulator. The R-value of fiberglass varies with the density of the glass. However, the R-value of cellulose insulation is 3.7 per inch, whereas for fiberglass, it is around 3 or 4 per inch. However, the efficacy is determined by the overall R-value and not the per-inch value. Generally, fiberglass insulation has higher value.

Energy Loss
There are various gaps, voids and spaces present between the wall and the insulated material that may not be visible to the naked eye, but they form a major factor in judging the performance of insulators. A study has shown that cellulose insulation has the ability to save 20% to 30% more energy than fiberglass insulation. Air infiltration is comparatively lesser in cellulose insulation than fiberglass. Soundproof recording studios also employ insulation in order to avoid noise. For sound insulation, like in a recording studio, both fiberglass and cellulose insulation are used.

Moisture Control
Fiberglass doesn't absorb water when wet, while cellulose insulation absorbs water and becomes wet, owing to the fact that it's made out of recycled newspapers and cardboard. If the cellulose insulation becomes wet, chances are there that its fire retardant ingredients may wash away and its R-value may also decrease. The cellulose does dry out and may regain its R-value, but it takes nearly two to three months to dry once it gets wet.

Fire and Health Concerns
Fire safety is an essential parameter that judges the effectiveness of insulators. Fiberglass insulation is not inflammable, but it contains formaldehyde which can produce toxic fumes, in case of a fire. Also, if the skin comes in direct contact with fiberglass, it can lead to skin irritation, cuts and rashes. The fiberglass is sealed in plastic cases, so that during installation there is no harm to the house owner or the workers. Cellulose on the other hand is extremely inflammable and many fire-resistant agents are added to it. Boric acid, a poisonous salt found in cellulose, is harmful if it comes in contact with the skin. It is advised to wear safety masks while installing cellulose insulators as the cellulose dust may cause breathing problems.

Fiberglass vs. cellulose insulation, which is better? Be it fiberglass or cellulose insulation, both are used all over the world depending on various factors, and it is always preferable to seek an expert's advice before making a choice.