How Insulation Works
Insulation Types
There are two types of materials commonly used for insulation in today's homes: fiber glass and cellulose. Fiber glass insulation is spun from molten sand and recycled glass into fibers. Cellulose insulation is made from recycled newspapers, which is then treated with a chemical flame retardant.
Both fiber glass and cellulose insulation can be made into "loose-fill" insulation, which can be blown into areas such as attics and walls with a blowing machine. Fiber glass insulation also comes in "batts" which are pre-cut pieces of insulation that vary in height and length.
R-Values
R-Values Insulation is measured in "R-Value" which is the capacity of an insulating material to resist heat flow. The higher the R-value, the greater the insulating power!
When you're purchasing insulation, buy or specify R-value, not inches, as R-values of material vary. To achieve higher total insulating power, R-values can be added together. For example: R-38 added to R-11 insulation results in R-49 insulation.
Why Fiberglass
Cellulose insulation is messy to install and, despite its chemical flame retardant treatment, can burn when exposed to a heat source. Thus fiber glass is a preferred insulation material by most builders and homeowners. It is inorganic, and noncombustible. Fiber glass will not deteriorate or lose its insulating power over time. Fiberglass also boasts the qualities of resistant to water absorption, an excellent sound absorber, proven in tests for assuring thermal performance, extremely safe when installed professionally.
Controlling Moisture
Insulation does more than help control the flow of heat in and out of your home. It also helps control the movement of moisture and water vapour that a family generates during a variety of every day activities like cooking and cleaning.
During the heating season, these vapours move from a home's warmer interior to the cooler exterior where moisture can condense. Condensation over extended periods of time can cause wood to rot, or the growth of mildew and molds. It may also lower the efficiency of the insulation. That's where vapour retardants come in.