Home Construction Glossary: R-13 Insulation

A Reason to Insulate: Heat Transfer

Heat always moves from hot to cold. Hot air can move through several mechanisms but the most common method of heat loss for homes and buildings is through conduction. Conduction is the heat transfer through materials that touch, the same way that heat is transferred from a pan to the pan’s handle and gets hotter as the pan heats up. As heat moves into your house during the summer or out of your house during the winter, it is best to add a material that slows that transfer down. The type of material and the thickness depends on when the building was built, the space available, and how well the building needs to be insulated. As the heat transfer is slowed down, the temperature inside the building or home will be regulated better and ultimately the cost associated with heating or cooling the building will be reduced.

A brief look into the History of Insulation

Thermal insulation was first utilized using animal skins and furs. Later, other natural products came about such as mud and straw in an effort to further insulate people from environmental conditions. Insulation was used by ancient Egyptians, Vikings, and other pre-historic civilizations most often in the form of filling cracks or gaps in their shelters with mineral-based or vegetation-based materials. Asbestos, a naturally occurring mineral, has even been used as chinking in log cabins that are over 3,000 years old. The ancient Greeks, among others, used asbestos as flame-resistant insulation on clothing and other materials that were used near high heat. While asbestos has been found in ancient homes and is naturally occurring, the Industrial Revolution at the turn of the 20th century gave way to the more pervasive use of other naturally and artificially made materials. It is also around this time when the health hazards of using asbestos became clearer. It is well known today that asbestos and other materials that cause fine needle or powders when working with or around them cause respiratory damage and possibly cancer.

Modern Insulation

Modern insulation is composed of materials that require more manufacturing. Today, insulation is rated by its thermal resistance which is a measure of how well it resists changes in heat transfer and can be compared by the R-value. When installed in a wall, different materials will have different R-values as they are restricted to the dimensions of the wall and each material will have its intrinsic thermal resistance. Commercial insulation is often sold in bats that are pre-made to standard wall thickness. For example, R-13 fiberglass insulation is lightweight, shapeable, and sold in bats that are ideal for most houses and buildings throughout the country for wall insulation. Fiberglass insulation is also flame and rodent resistant as it is not flammable and is very difficult for a rodent to chew through. Installation does not require any special tools or curing time. R-13 fiberglass insulation is not only an effective insulator but it also safe to handle and have in your home.