Get Matched with
the Best Contractors
near you!

Let's help you find a contractor!

Tell us which service you need and your zip code to get started.

Rating Highest
Reviews Higest
Promiximty Closest

Understanding Insulation R-Values


Understanding Insulation R-Values

June 20, 2019

When it comes time to select insulation for your home, whether you're building a new home, putting on an addition, or updating your home's energy efficiency, there are certain factors you should consider. The most important being the R-value of the insulation you're considering. Your home will be more comfortable with the right insulation and choosing a material with the proper R-value will make a world of difference.

What is R-Value?

Each type of insulation material has a different R-value or thermal resistance rating. The "R" refers to resistance to heat flow. The higher a product's R-value, the more effective it is at insulating.

What is a Good R-Value?

The R-value most appropriate for your home can be impacted by the climate where you live, the way your home is built, and how your home is heated and cooled. Though in general, the higher the R-value of an insulation product, the greater its insulating power.

Most insulation manufacturers are required to disclose the R-value of their products, which will aid in your research when trying to decide which type of insulation to choose for your home. "The FTC enforces the R-value Rule, which ensures that you get accurate, honest information about the R-value of your insulation before you buy it, have it installed, or buy a new home. Manufacturers must label their packages of insulation; installers and retailers must provide fact sheets; and new home sellers must include this information in sales contracts," according to the Federal Trade Commission.

Typical Insulation R-Values (per inch)

BPI (Building Performance Institute Inc.)

Insulation Type R-Value Common Application
Cellulose, loose fill 3.7 Attic floor
Cellulose, high density 3.2 Walls, enclosed cavities, framing transitions
Fiberglass, batts 3.0* Basement ceiling, open stud walls, attic floor
Fiberglass, loose fill 2.8 Attic floor, existing walls
Rockwool 3.0 Attic floor, walls, basement ceiling
Vermiculite 2.7 Attic floor
Low density urethane, sprayed foam 3.7 Attics, walls (new construction), sill plate, band joist, framing transitions
Urethane, sprayed foam 6.0 Attics, walls (new construction), sill plate, band joist, framing transitions
Urea formaldehyde Foam 4.0 Attics, existing walls

*R-value of 3.0 per inch for fiberglass batts is achieved when the batts are tested in a fully enclosed, 6-sided box, with the batt insulation being fully fluffed, touching all six sides with no gaps or dirt.

Does the R-Value of Insulation Deteriorate Over Time?

Insulation is intended to last for the life of the structure, but when the structure's environment is challenged, it can impact the insulation. So, in reality, the R-value of most insulating products will decrease over time. A few of the most common reasons for R-value deteriorating include:

  • Batt and blown insulation slumping in wall cavities
  • Insulation damage from moisture
  • Shrinking and gaps in rigid foam insulation

Improving Your Home's Energy Efficiency

Adding the proper insulating materials to your home and in the proper areas is a critical first step to improving your home's energy efficiency. Be sure to ask your insulation contractor about the R-value of the products they intend to install.

HomePro Match can connect you with a home energy efficiency expert who will provide you with an in-depth consultation and recommendations to improve your home's energy efficiency.

For more information on insulation options, contact a HomePro Match insulation contractor today!

Related Insulation Articles

View All Articles

Thousands of contractors
are ready to help!

Let's find the one for you!

Tell us which service you need and your zip code to get started.

Rating Highest
Reviews Higest
Promiximty Closest