Actually I recommended an over the roof install because that is the only place on my entire property that I have a view of the arc. Luckily it's a great view there. I need to peak the dish right now, but I have gotten from 55.5 to 148 west.
I have a 16 inch overhang and concrete tile roof. The roof peak is about 20 feet above the ground, but I put my pole down a little - like at about 17 feet.
I pulled my two or three concrete tiles out and drilled a four inch hole in the supporting 3/4 inch wood with a drill and a hole saw. The 3 1/2 inch pole by about 30 feet I got from my local scrap yard, bringing in the polar mounting part of the bracket to make sure the fit was right. I got a thin wall pipe. I stuck the pipe through the hole and just sat it there before digging any footing. I used a level to plumb it up, both north south and east west. The larger hole in the overhang worked because my wall on the end was leaning in some and I could use the oversize hole to move the pole until plumb.
Then I dug my footing. I have a concrete sidewalk on the side of my house, so I only went down maybe 2 feet, and I put some "L" shaped rebars in the bottom of the pole. I plumbed the pole up where it sat as close as I could and filled the hole with ready mix concrete.
I went up to the roof line and used the level again in both directions. I held the pole plumb in the hole with wooden wedges. Some guys thing I'm crazy but I filled the pole with ready mix concrete ( I made a big concrete funnel with some sheet metal and brought it up a ladder, buckets half full). After filling, I used a rubber mallet to hit on the pole until I worked the air out of the pipe. It has never twisted, even in serious wind. After the concrete cured and I checked again for plumb, I used a circular saw with an inexpensive diamond blade (about ten bucks at Harbor Freight) to cut slots out of the concrete tiles. After getting the tiles back in, I used some more ready mix to fill in around the pole.
My roof does not have a steep pitch so I am able to get up there and change lnbs and make adjustments. That may not be your situation.
But I am happy with my install, my friends say it looks professional, and I get to keep all of my yard space for other things.
Every property is different, but I just want to tell you what I did as a homeowner, by myself, total cost a hundred bucks, pole included,