If the attic and roof and roof area is the standard wood framing with wood or vinyl siding with composition singles and no metal backed insulation. . In the attic aim the Antennas Direct C5 at about 286 degree magnetic compass , north west because CFRE-DT channel 11 GTN is the weakest Tv station. Here is how to aim antennas ,
http://www.kyes.com/antenna/pointing/pointing.html. The other 3 Tv stations are so strong that they will be receivd no matter which way the antenna aimed. Yes the Digital Tv stations will be received with the antenna in the attic. Scan the Tv for new channels from time to time because new Tv stations and channels can begin transmitting at any time with out notice.