Close Menu


[contact-form-7 404 "Not Found"]

Do You Have Enough Attic Insulation? How to Measure R-Value

Do You Have Enough Attic Insulation? How to Measure R-Value

April 12, 2019

enough attic insulation

A well-insulated attic can make a dramatic difference in the temperature balance in your home and in your annual heating and cooling bills. Do you have enough attic insulation?

The clearest answer to this question lies in the resistance value (R-value) of your insulation. If you are currently scratching your head and wondering what language we are speaking in, continue reading for clarity and answers from the pros at DFW Thermal Solutions on how to measure R-value.

Do You Have Enough Attic Insulation?

Firstly, perform a visual inspection of your attic space. If you see that your insulation is level with or below the top of your floor joists, you do not have enough insulation. However, if you can’t see the joists because insulation is above them, you should move to the next step of measuring the R-value between two joists.

Defining R-Value 

First and foremost, you should learn how R-value is defined and how it measures the efficiency of your insulation. With the “R” standing for “resistance,” R-value grades insulation products on how resistant they are to thermal flow. The higher the R-value rating, the better the product is at insulating a space.

How to Measure R-Value

Measuring the R-value of your attic space is an important first step in determining any insulation upgrades that must happen. For the safest method, follow these steps:

  • Safety First – Because insulation material is commonly made of fiberglass or other irritants that can be inhaled, make sure you have a dust mask, gloves, and work clothes that cover exposed skin.
  • Find Your Floor Joists – After accessing your attic, you will probably support yourself as you work by standing on joists in the attic floor. These are important to locate not only to move about safely, but for the next step.
  • Determine What Type of Insulation You Have – Examine the insulation between joists. If you see light-weight yellow, pink, or white material you probably have fiberglass. If you find dark gray or off-white material, it’s likely rock wool. Small, gray fibers or flat pieces indicate cellulose, while blankets of light-weight yellow, pink, or white indicate fiberglass batting.
  • Measure Between Joists – Now that you know what your joists are, extend a tape measure into a joist bay (this is the insulated space between two joists.) For this step, you should push the tape measure all the way down until it touches the drywall.
  • Record the Measurement – Examine where the tape measure meets the top of the insulation and record the corresponding number.
  • Calculate Your R-Value – Now that you have a measurement, you can multiply the number you recorded by the factor associated with the type of insulation you have. Here are some generally-accepted factors used to determine the R-value for spaces using different types of insulation:
  • Loose Fiberglass: measurement times 2.5
  • Rock Wool: measurement times 2.8
  • Cellulose: measurement times 3.7
  • Fiberglass: measurement times 3.2

Fix Your Insulation Issues with a Professional Touch!

Are you still wondering if you have enough attic insulation? Allow the team at DFW Thermal Solutions to lend a hand. With professional skills and experience you can trust, our pros are ready to find the best solutions for any of your home insulation projects. Call us today at 972-382-7124 or fill out a service request form on our website!