Insulation is key to keeping your home comfortable and energy efficient. But with all the different types of insulation and technical terms, it can be confusing to know which product is right for your home. To help you make the best decision for your needs, here’s a list of basic insulation terms that every homeowner should know.

Fiberglass Insulation

Fiberglass insulation is one of the most common types of insulation. It’s composed of glass fibers spun into a mat and bonded together with a resin. Fiberglass insulation effectively blocks heat transfer in walls, ceilings, and attics.

Spray Foam Insulation

Spray foam insulation is a type of insulation made from polyurethane or other synthetic materials. It is lightweight and moisture-resistant and is helpful for insulating small holes and cracks.


R-value is a measured value of an insulation’s ability to resist heat flow. The higher the R-value, the greater the insulating power.


K-value measures an insulation’s conductivity (the rate heat travels through a material). The lower the K-value, the better the insulation.


C-value is a measure of an insulation’s ability to store heat. The higher the C-value, the more heat the insulation can absorb.


A measure of an insulation’s overall thermal efficiency (taking into account both R-value and C-value). The lower the U-value, the better the insulation.

Vapor Barrier

A vapor barrier is a material that prevents moisture from passing through it. Vapor barriers are important in insulation to prevent mold and mildew growth.

Energy Codes

Building codes establish minimum requirements for energy efficiency in new construction and renovations. Energy codes vary by state and locality, but most require some form of insulation in exterior walls, foundation walls, and ceilings.

Finding the Right Insulation for Your Home

Now that you know the basics of insulation, you can start shopping for the right product for your home.