Earlier this week we had a nice brisk morning and I was running a little early to my 8am sales call. I decided to drive around the neighborhood I was in to check out some of the homes roofs near my appointment. Why in the world would I want to look at a roof at 7:30am? Well, believe it or not you can tell a lot about the insulation of an attic, ventilation of an attic, air leaks and possibly discover some other issues within a home by checking out a roofs frost patterns.
The frost pattern or frost on a roof is different than the snow on a roof, so this little bit of advice won’t do you much good with the snow on a roof. You see the air inside your attic is considered outside of your building envelope, or outside of your home, therefore the temperature in your attic should be at or close to the same temperature as the outdoor air temperature. This is only true, however, if your attic is properly insulated, vented and sealed off from your living space below. So in the early morning hours before the sun is out you should see no difference in the frost pattern across the roof. Once the sun hits the roof it is hard to see the trouble area since the frost will melt quickly.
There were a few homes in this neighborhood with some major issues. The biggest issue that I found was with the two story home to the right in my photo. As you can see, there are two large sections of frost on the shingles, but no frost at all towards the top of the roof line. This home has the same layout, or design, as the other two homes in the photo, so in reality they should all have a fully frosted roof. I am guessing that on the upper home, with the issues, the two sections with frost have rolled insulation in an attic or ceiling space and the bare spots are probably blown in insulation above a ceiling. This troubled home probably has several air leaks from the second floor into the attic such as can lights, bathroom exhaust, vent pipes and may have leaky ductwork in the attic as well. Whatever the case may be they are spending a lot each year to not only heat their home but also to heat their roof.
So the next time you look out your window, before the sun comes out and see frost on the ground, slip on your warm slippers and check out your roof to see what you may discover. You may find that just doing a little insulating or sealing can help save you some big bucks and keep your home more comfortable year round. Hey, don’t worry about the pigeons; they can go to your neighbor’s roof to stay warm.
Thanks and have a great Holiday Season!
James Gallet