Techshield foil-backed OSB roof decking
 

My wife and I are building a home in Alabama, and I chose to incorporate Techshield foil backed roof decking. The foil is on the surface inside the attic. How will the foil affect attic antenna performance?

The foil will block most if not all of the RF signals (radio, TV, satellite, etc.) from penetrating the roof deck. That attic will be a very unlikely place to find successful reception.