here is so pretty interesting findings..
I took my radio shack discone antenna, connected to 50 foot of Radio Shack RG-8/U cable and I went up into my attic. Didn't really get good reception at all up there. Then I took it onto my roof, and put the discone sitting up there on the shingles at different locations, from one side of the roof to the other. I found pretty good signal in the middle of my roof, okay signal on the right side, and horrible single on the left side of my roof. My roof is a standard straight bi-level roof which is about 60 foot long... so this was weird I thought. Then I even took the Discone antenna and held it up over my head as high as I could but this didn't do any better for the reception. So I don't think a 10' mast would even make a difference.
Then I got down from the roof and just stood the Discone up on my deck which is connected to the second floor of my house. Surprisingly this is where I get the best signal. I can pick up an airport about 25 miles away, both the tower and planes and I get local police, etc. very strong. It is just weird to me why putting the antenna on my deck which is lower than my roof actually gets me better reception. And also the fact that you have the house blocking the other side of where the signals may be coming from when the antenna is on the deck, but this is just weird I guess.. so it doesn't look like a roof mount is needed, but now the issue is that I need to get longer coax runs, like up to 100feet now to sit the antenna on my deck cause it's at the other side of my house versus where my office is!