Often, when you see information about different types of insulation, you’ll see something called an R-value attached to it. But if you don’t understand insulation and the associated technical terms very well, that term could be a frustrating one for you.
What is R-value?
Basically, R-value measures how well something conducts heat. With insulation, R-value measures the heat resistance. Something with high heat resistance is going to hold heat in your home, business, or other building better than something with a lower resistance. It may also be called the materials thermal resistance.
The R-value depends on the type of material and is measured per inch. To determine the R-Value of an insulating material, experts at the American Society of Testing and Materials perform a series of rigorous tests. Factors that help determine the R-Value include the materials type and thickness.
Insulating Materials and their R-Values
- Closed-Cell Polyurethane Spray Foam: 6.3
- Open-Cell Polyurethane Spray Foam: 3.9
- Cellulose Wall Spray: 3.8
- Dense-Pak Cellulose: 3.8
- Blown-in Cellulose: 3.7
- Fiberglass: 3.2
- Cotton Fiber: 3.2
Seems like a whole bunch of numbers that don’t make much sense! Make sure to keep in mind that R-Values are based and tested in an absolute zero wind and a zero moisture environment. These are not real life circumstances and the R-Value of insulating materials can be misleading.
What R-Value means for you
As noted above, R-value doesn’t have but so much real-world applicability. But it’s the standard measurement for insulation materials. It’s good to know when making a decision on what type of insulation to get in your home.
Now, when you see this, you’ll note that the most common type of insulation, fiberglass, is near the bottom of the list. This means that when it comes down to it, you’re going to spend more on energy bills every year with common blanket insulation than you would for something like spray foam.
Builders have been using fiberglass blanket insulation in homes for decades. If you live in a home that was built anytime within the past 50 years or more, chances are they used fiberglass. Everyone knows that older homes are a bit drafty, right? Well part of that is the fiberglass insulation. Replacing your insulation with spray foam will keep your home significantly more comfortable as well as saving you thousands of dollars.