Radiant barriers are materials that work in conjunction with insulation
to prevent heat gain and loss and keep the inside temperature of your home at a constant. The most commonly used radiant barrier in residential construction is installed in the attic. Because the attic can be a large source of heat loss, consider adding a radiant barrier if your attic does not all ready have one.
A radiant barrier works by reflecting heat or cold that permeates through the roof. If it is a sunny day, the heat may radiate through your roofing material and into your house. If a radiant barrier is installed, it reflects most of the heat back to the roof, rather than letting it invade your attic. This technology, combined with the proper insulation can significantly reduce heating and cooling energy costs.
In the winter, the radiant barrier can also help keep the warm air inside the house. However, it will also reflect a large amount of heat you would receive from any sun in the winter. Even with this disadvantage, overall you will most likely save energy unless you live in a particularly cold climate.
If you are considering adding a radiant barrier to your attic, the easiest method may be to add the material directly over the existing insulation. The reflective side of the material should always face up. This method of installation that has the material placed directly onto the existing insulation is called an attic floor application.
Another popular method involves attaching the radiant barrier to the roof. You can attach it underneath an attic truss or the existing attic rafter framing. If you are putting on a new roof, you can put the radiant barrier over the rafters before the roof deck is installed. You could also consider installing the radiant barrier on the underside of the exposed roof deck.
The type of radiant barrier you will need will depend on your installation method. Normally made of a thin sheet of reflective material that is applied on another stabilizing material such as plastic, paper, or plywood, a radiant barrier can come in many different forms. There are also versions that are reinforced with fiber, making them easier to work with while still maintaining their thin profile.
Installing a radiant barrier in your attic can be a simple process, but only if you are knowledgeable on how your home is constructed. If you have only a hazy idea of what rafters are or aren’t sure how to access your attic, call a professional. A licensed contractor or handyman should be able to install one in an attic in a single afternoon.