If you are planning on installing a radiant barrier on your garage door, one option is to use foam board with foil attached to one side. You can purchase pre-made foiled foam board at home improvement stores, or you can make your own.
Making your own is actually quite simple and can, in some cases, be more economical that purchasing the pre-made version.
Simply purchase your foam board, and then cut strips of AtticFoil® radiant barrier to size for the board. You can attach the foil with an adhesive that can withstand high temperatures, or you can use some foil tape to secure the foil on the ends. Feel free to get creative with how you adhere it - there are no hard and fast rules; just make sure you keep in mind that the foil can get hot since it will be facing in, toward the metal door.
As you can see from the photo on the right, customers do make their own foil-faced foam board and it is a great way to add R-value without adding bulk to the assembly.
With garage installations, it's important to keep in mind that ventilation is equally important so that the air temperature in the garage stays close to ambient (outside) air temperature.
Another option for garages are pre-made "garage door kits" and there is nothing wrong with most of these products. The main thing you need to look for is a product that instructs you to install it so that the radiant barrier portion is facing an air gap. This is critical since no radiant barrier can work without an air space. Why? Simply because radiant heat is heat that travels across an air gap (or vacuum) and if there is no air space, the type of heat is conductive, not radiant, and therefore a radiant barrier would be totally useless in that case.
Do you have any garage installation photos you'd like to share with us? Please feel free to email them to us at support (at)atticfoil(dot)com or you can post them on our AtticFoil.com Facebook page.