Installing your new roof can be the perfect time to add a radiant barrier without too much additional outlay in time or cost. Before you decide to do so, you should first understand how radiant heat works, so you install a barrier that actually IS effective, and doesn’t just claim to be. Radiant heat is radiation that travels across a space in wave form. The space can be comprised of air and/or gasses or a vacuum. Though this may seem pretty basic, it’s important to understand this principle when evaluating the claims of various products.
There are some foil roofing products on the market that are marketed as radiant barriers when installed directly under the shingles on your roof. While the foil itself may reflect heat, this is not radiant heat, since the waves are moving through an adjacent object and not through a space. It would be considered conductive heat instead. If the shingles are placed directly on the foil, radiant heat cannot be generated since there is no space through which it can move. While some product manufacturers correctly state that, used in this fashion, it is a thermal, but not radiant barrier, some roofing companies may purposely, or inadvertently still sell it as a radiant barrier.
Knowing all of this, you’re probably still wondering if there is any easy way to install a radiant barrier under your shingles. Fortunately, there is! Once your roofing company understands that YOU understand how radiant heat works, they should be happy to help you come up with a solution. The key is to create some kind of air space between the barrier and the shingles. This can be accomplished with metal, tile or other “raised” type roofs that can provide the required air space. This is usually achieved with wooden battens.
The batten method is quite common and simple to do. Roofing felt or some other type of roof underlayment should be rolled out as usual, followed by a layer of reflective barrier foil. Make sure the foil is perforated so moisture can escape and condensation doesn’t build up. Wooden battens are then installed over the barrier, and then the metal, or tile roof is installed. This method will leave a space for the radiant heat to be reflected away from the roof decking. If possible, small spaces should be left between the battens to allow for even greater airflow.
While this method is usually more expensive and adds a step to the roofing process, if it’s done correctly, you can be assured that your radiant barrier will work properly. Understanding the simple principle of radiant heat will help keep you from falling for scams or products that are incorrectly installed. Your home will stay cooler, helping you to save on energy costs for many years to come.