ISSUE
Increased attention is being paid to achieving energy efficiency through a roof system. In the case of a building with a properly vented attic, the roof system has little impact on winter efficiency. That must be achieved with insulation on top of the ceilings. However, if the roof system can reduce attic temperatures in the summer, then it can have an impact on cooling loads and subsequent energy costs.
ANALYSIS
Many contractors are promoting the installation of radiant barriers when roofing is installed. Radiant barriers are basically a shiny aluminum foil or similar material, sometimes laminated to a scrim or paper backing for strength. The manufacturers of radiant barriers often make substantial claims about the ability of their products to reduce energy costs. It is Classic Products’ opinion that these claims are often exaggerated or perhaps based upon certain parameters which one would never see in normal building construction. However, we also feel that properly installed radiant barriers can have some benefit.
CONCLUSION
It is our suggestion to make sure that the cost of a radiant barrier is reasonable. Otherwise, the period for payback in energy savings will never be realized by the property owner. It is always advisable to consult closely with the installing contractor and the manufacturer of the barrier to make certain that installation will be occurring in a way which permits maximum effectiveness of the material. As an example, the shiny side of a radiant barrier must face an airspace. If it is tight against another component of the roof system, all efficiency is lost because heat will then be transferred by conduction and will not be blocked by the radiant or reflective qualities of the barrier.
