Hot Roof vs. Cold Roof: To Vent or Not to Vent?

If you have been considering a new roof installation, looking into adding insulation to your home, or are planning to build a new house, you may have heard people talk about “hot roof” and “cold roof” systems. However, you may not be familiar with these concepts, particularly what they mean and the pros and cons of each.

In this case, you can learn a lot from Foam-Tech’s article, Vented vs. Unvented Roofs, which provides a detailed explanation of each. Basically, the term “cold roof” refers to a traditional roof, or vented roof, while “hot roof” refers to a roof that is not ventilated and which has foam insulation attached directly to the roof sheathing.  The theory behind a hot roof system is that rather than allowing heat to escape through your roof, you contain it in your attic space, which can save on utility costs… in theory.

Here are some of the pros and cons of each type of roofing system.

Cold Roof: The Most Commonly Chosen and Installed Roofing System

The term “cold roof” refers to traditional roofs in which insulation is placed in the ceiling of the home, so it is underneath the attic space, which is not conditioned. These roofs include a .


  • Ventilated roofs remove moisture from roof cavities, structural members, sheathing and insulation.
  • A properly insulated ventilated roof can help to control or prevent the formation of ice dams.
  • Because the sheathing is kept cooler, roofing materials tend to have a longer life span.
  • These roofs keep your home cooler during the hot summer months.


  • These roofs do allow a bit of heat to escape from your home through the roof in the winter months
  • The roofs can fail if the roof assembly is not properly installed or insulated or if the outside air is unable to absorb moisture faster than it is accumulated.

Hot Roof: A System Most Likely to Be Found in Newly Built Homes

The term “hot roof” is something of a misnomer, as the attic space will only be a few degrees warmer than in a traditional roof. These roofs have some pros and cons, as explained in the article.


  • When properly installed, unvented roofs perform well and cause no excess moisture accumulation.
  • These roofs can lower your heating costs in the winter.
  • If water or air ducts run through your attic space, they are less likely to be affected by extreme temperatures, and this can save you money on utility costs.
  • According to the Homeowners & Trade Resource Center (HTRC), a properly conditioned and sealed attic will eliminate the formation of ice dams.


  • Unventilated roofing systems will fail if the home does not have a tight building envelope that includes air barriers and vapor retarders.
  • Hot roofs can create a “stack effect.” This is because the attic space will be under positive pressure, and this can the lower, living space of the home to be under negative pressure, which forces outside air into the home through any holes in the building envelope, such as through leaky windows or underneath doors.
  • Because the roof assembly is exposed to more heat, roofing materials may wear out faster, requiring a new roof installation sooner than you might have hoped.

You can learn more by reading the full article here.

Whichever type of roofing system you decide to go with, it is important that you ensure it is installed correctly. If you are in the market for a new roof installation and you own a home in the southwestern Chicago suburbs, be sure to contact Baltic Home Improvements for an estimate. Our award-winning team of experienced and qualified roofers will be happy to answer your questions and provide you with a free estimate for your roofing job. Learn more about what Baltic Home Improvements can do for you by contacting us today.