After you've decided to install a radiant barrier product
After considering the options and deciding to use a radiant barrier in your attic, there are several things you should do to optimize the performance. Most important, you must insure that the installation follows all the guidelines and recommendations provided by the manufacturer. Other guidance is provided in two ASTM Standard Practices for the installation of radiant barriers. Find out if your contractor follows these practices.
To obtain the best performance with both radiant barriers, the gable ends of the attic should also be covered, but do not cover the gable vent area. For attics that are open to the space over garages or carports, the radiant barrier should extend eight feet or more into the garage or carport to achieve the same effect. It is not necessary to cover the gable ends if a radiant barrier is placed on top the attic floor insulation.
| If a radiant barrier is reflective on only one side, the reflective side must face toward the main attic space, regardless of whether the radiant barrier is at the rafters or the attic floor. |
While working in the attic to install a radiant barrier, care should be taken not to compress existing insulation present in the attic. The effectiveness of the existing insulation is dependent upon its thickness, so if it is compressed, its R-value is decreased
If you select a radiant barrier product, you have several installation location options. If you select an interior radiation control coating, you should be sure that the application covers ALL the roof support structure connected to the roof deck.
| Installation Options | Non-Energy Consideration |