What Is A Radiant Barrier Roof?
A radiant barrier roof is a type of roof that is designed to reflect heat. If you’ve ever wondered why some attics are lined with shiny metallic-looking material, this article will explain the ins and outs of the subject.
How Does It Work?
As we already mentioned, this type of roof works primarily through the reflection of heat. The inside of the attic lined with a highly reflective material such as aluminum. Under normal circumstances, attics tend to be very hot. This happens because of the sun’s heat bearing down on those roofing tiles/shingles.
As the sun raises the temperature of the roofing tiles, these tiles absorb all the heat that they can. Remember: Heat is energy, and a given object can only absorb a certain amount. So, when the tiles are fully heated, that extra energy needs somewhere else to go. Usually, it will be absorbed by the closest material, which is the ceiling of your attic. When that ceiling cannot absorb any more heat, the heat begins to transfer to the walls, and so on. This sets off a chain reaction whereby your entire house becomes hotter than it should be.
Radiant barrier roofs prevent your house from transferring heat by simply reflecting that heat away. Hot air has a tendency to rise under most circumstances, so it doesn’t take a whole lot of reflection to do the job. A shiny material is generally all that you need, though (obviously) some materials are better than others.
There are several proven benefits to this type of roof. Let’s start with the most obvious one: Keeping your home cool in the summer. During the hottest days of the year, anything that lowers the temperature of your home is a blessing. In this situation, most people will simply run their air conditioner. However, this creates a drain on the electric bill. The hotter it gets, the harder the AC will need to work. The harder it works, the more electricity it will drain.
That brings us to the second benefit of this type of roof: A lower electric bill. By keeping your home from reaching a high temperature in the first place, you reduce the amount of work that your AC needs to do. But how much power will you really save? This study attempted to give a definitive answer. By measuring the amount of heat absorbed by the home, and comparing it to the amount of heat reflected, they were able to determine that the radiant barrier reduced heat transfer by 40-50%. That can only translate to a serious discount on your next utility bill.
Let’s start with the most obvious downside: These roofs are specifically meant for hotter climates. They don’t really offer any benefits in the winter, although they might offer a little bit of extra insulation against the cold. Thus, those who live in colder climates may not find a radiant barrier roof to be worth the cost.
It should also be noted that radiant barrier roofs are not equally effective for all homes. For reasons that are not completely understood, certain types of building dimensions will encourage heat flow and undermine the effectiveness of the radiant barrier. The level of heat reflection can be affected by a number of things, including the slope of the roof, the type of roof shingles used, and ventilation.
Another little problem is the fact that radiant barriers will often require extra insulation. This is necessary to prevent all transfer of heat from one part of the house to another. Of course, this means an extra expense and/or some extra time and trouble.
This biggest problem with a radiant barrier roof is the fact that moisture will often collect on its interior surface. When the water vapor from inside the home is evaporated, it tends to travel up, which can only lead it to the attic. Because radiant barrier materials repel moisture as well as heat, the water vapor has nowhere to go. Thus, it turns into little droplets that run down the barrier and into your attic. This problem is particularly common in cold weather.
In general, this isn’t a hard choice to make. If you live in a particularly hot climate, a radiant barrier roof is a great choice that is likely to increase your comfort level. However, those who live in colder climates will likely find that this isn’t the roof for them. As we mentioned, condensation can be a problem for these barriers, but this problem only manifests in cold weather. Thus, your choice is a simple one. If we have helped you to make an informed and intelligent choice, we hope that you will show your appreciation by filling out the contact form below.