While most homeowners know that insulation is important, most don’t fully understand how it works, and what the differences are between various types of insulation.

So, What Does Insulation Do?

The main purpose of insulation is to control the flow of heat and cold. In the warm months of the year, insulation keeps heat from entering the home. And in the colder months, it keeps warm air inside the home while preventing the outside temperatures from seeping in.

What Does R-Value Mean?

The R-Value of insulation refers to the measure of how well your insulation material resists the flow of heat.
R-Value takes into account the thickness of a material, as well as is compactness. The higher the R-Value of your insulation, means increased protection from the invading heat or cold. There are multiple factors for choosing the right insulation for your project. R-Value is probably the most important consideration.

Common Types of Insulation

Fiberglass Insulation

Typical R-Value per inch: R-2.9 to R-3.8
Also referred to as Batt Insulation, this is the most commonly used insulation. It’s inexpensive to purchase and available in easy to install sheets or rolls. Homeowners often choose to install it themselves to save on construction costs. One of the main downsides of Fiberglass insulation is that it is very vulnerable to moisture damage. Wet fiberglass insulation loses all R-Value and almost no insulation properties until it completely dries out.

Cellulose Insulation

Typical R-Value per inch: R-3.1 to R-3.8
Ideal for attics and roof cavities, cellulose can be blown in instead of placed by hand. It tends to be an eco-friendly choice because it’s made from recycled paper or wood fibers. The cost is higher because it must be professionally installed. But it boasts a higher R-Value than fiberglass insulation. However, the R-Value may decline if the cellulose gets wet or settles over time. It also does not create an airtight seal. Therefore, an additional air barrier/vapour barrier is needed.

Rigid Foam Insulation

Typical R-Value per inch: R-4 to R-6.5
Available in several thicknesses, many prefer working with the solid foam sheets as opposed to rolls/sheets of fiberglass. Most varieties of rigid foam have a higher R-Value per inch than fiberglass, cotton, or cellulose. The sheets can be cut to the required size but must be tightly fit to prevent air loss. Vapour barrier is still required and R-Values of some rigid foam sheets have been reported to deteriorate over time.

Spray Foam Insulation

Typical R-Value: R-6.5 to R-7
Closed-cell spray foam boasts the greatest R-Value than other insulation options. The liquid material is sprayed on and expands to a thick foam barrier. Spray foam outperforms rigid foam and fiberglass for getting into tight spaces as it expands in place to fill any gaps and seams. It is resistant to water, eliminates the need to use vapour barrier, and the R-Value remains consistent for the life of the product. However, spray foam needs to be professionally installed which adds to the initial cost.