I LIVE IN A HEAVILLY WOODED AREA 40 MILES FROM MOST OF THE LOCAL STATIONS, WITH THIS ANTENNA ONLY 8 FEET HIGH ON TOP OF MY SHED IN THE BACKYARD. I CAN CURRENTLY RECEIVE 22 CHANNELS VERY WELL WITH ONLY MINOR PIXELIZATION HERE AND THERE.
SO IN MY OPINION, ON A 2 STORY ATTIC YOU SHOULD DO MUCH BETTER.