Fiberglass is a type of plastic with reinforcement fibers made of glass. It is constructed by bundling together thin glass strands, forming a material that is lightweight and economical. Fiberglass is used in such products as automobile bodies, hulls of boats, shower curtains, and roofing material. Fiberglass is also used as an insulator in buildings and vehicles to slow down the spread of heat, cold, and sound. It is an ideal insulator because it does not pose a fire hazard.
Fiberglass was first introduced as an insulation material in 1938, competing with asbestos, which was the standard insulation material at that time. It gained widespread popularity when people started becoming aware of the carcinogenic properties of asbestos, forcing builders to find an alternative insulation material. Fiberglass became the insulation of choice when people shied away from asbestos.
Fiberglass insulation, sold in either blanket form or loose fill, offers the following benefits:
- It is cost-effective.
- It does not shrink.
- It is available in sealed blankets or rolls to prevent inhalation of the fibers.
- Fiberglass batts are covered with plastic, which acts as a vapor barrier.
- It is fireproof.
- It uses recycled glass, which is good for the environment.
- It is generally free from insect infestation (insects do not eat fiberglass).
- It provides consistent layers of insulation.
There are also disadvantages in the use of fiberglass as an insulation material, including the following:
- Tiny slivers of fiberglass could be inhaled. Protective gear is required when installing fiberglass insulation.
- Inhaled fiberglass slivers may diminish lung function.
- Fiberglass insulation needs a vapor barrier (although batts usually come standard with a plastic cover to keep out moisture).
- Fiberglass batts may not seal ceiling and wall spaces tightly.
- Fiberglass sags, decreasing its R-value over time. (R-value is the capacity of insulating materials to resist heat flow.)
Despite some disadvantages, fiberglass is widely used in the construction industry. It is estimated that about 90% of American homes use fiberglass insulation. Not only does it contribute to energy efficiency, a significant amount of fiberglass insulation uses recycled materials, making it an earth-friendly choice.