This installation is considered to be the best method in hot climates where cooling is far more important than heating. This type of installation will generally keep the entire attic space much cooler compared to a non radiant barrier insulated attic, and will effectively block radiant heat from striking air handlers and ductwork in the attic. Also, any attic air which happens to leak into the return side of the ductwork will be cooler, causing less stress on the cooling equipment, increasing its efficiency and lengthening its life.

Although this installation method is the most efficient, it is also the most challenging and requires the most work and time to install. However, once complete, this is a maintenance free installation method requiring no cleaning as it is generally not affected by dust.

This installation method is the most common installation in the north, and easiest way of installing a Radiant Barrier in an existing attic. This method helps to reduce radiant heat gain through the ceiling in the summer and helps to retain interior heat in the winter. This installation method is susceptible to some dust accumulation, however Ra-flect™ Radiant Barrier is a double sided product and will continue to perform, but if left uncleaned, a slight degradation can be expected.