If you have completed a roofing project you may have noticed that a lot of insulation is involved. Over the last decade, insulation has increased from 3.3” insulation needed to reach “R” 20 to codes now requiring 4.4” insulation to reach “R” 25. There are two main reasons for this increase.

Understanding Roofing Insulation

  • Energy efficiency: As people try to increase energy savings, codes have become more stringent. More insulation results in needing less heating or cooling.
  • R-value per inch: Five years ago, 1-inch of insulation reached an R-value of 6 but research shows that these values needed to change because of foam aging. Today, 1-inch gives an R-value of 5.6. This eventually adds up as you get into larger R-values. To meet new building codes, you may experience an increase in insulation use of 57%. The good news is, that over time, you should see a return on those costs in terms of energy savings.

The Importance of R-Values

The insulation you choose should be based on R-value. With roofing, heat will move away from an area that is hotter to one that is cooler. Insulation helps restrict this movement. The R-value of a material is the measure of this ability. Higher values indicate better efficiency at preventing heat escape.

Do You Insulate the Roof or Ceiling?

The next factor to consider is where to install your insulation. Roof insulation involves placing insulation materials within the roof above the rafters. Ceiling insulation involves materials being placed within the floor nearest to the roof structure. Insulation should be a priority for a few reasons:

  • Regulated temperature
  • Energy savings
  • Reduced heat conduction
  • Prevention of water moisture

Ceiling insulation is much easier and uses loose-fill materials to spread along the surface. This is often cheaper and you can do this yourself. Insulating the roof typically involves hiring a roofing professional. If you are insulating the roof deck, the most common materials used are rigid foam boards and radiant barriers. Rigid foam insulation layers are installed using staggered seams. This is a good choice for reducing air leaks and limiting condensation and moisture in your roof. Rigid foam insulation allows you to achieve high R-values and is also environmentally-friendly.


Radiant barriers are great for warmer climates. This reflective insulation helps regulate the internal temperature by reducing the amount of heat absorbed into the surface. Radiant barriers are more expensive, but in the long run, you will save in energy costs. This is especially beneficial in warmer climates. Insulation is an important part of any roofing system. Reach out to us today for insulation questions and projects. Trust us to help keep your energy costs from going through the roof.


For any questions or to schedule a roof inspection, contact us today!