I'm in a metro area and the local transmitters are on a mountain, so I
get by with a 20' mast with an amplified saucer on top for OTA
channels. My place has aluminum siding, too. I just made a T with
some treated 2x4s and bolted a roof tripod to that. It and the mast
tubing are from RS. It sits on a concrete slab that originally had a
storage hut on it and the mast has 3 ground anchors and 6 guy wires.
Has been up for about 10 years now in 100+ mph winds. Have to tighten
the turnbuckles occasionally, but no maintenance otherwise. if I need
to, I can tip the thing down across the top of the T, very easy to get
up and down. I used hooks on one end of the turnbuckles. Have the
satellite dish on it now, too. The wooden T just sits on the
concrete, it's not bolted down at all. Very handy when adjusting
rough satellite dish orientation, just tap the leg the desired
direction, then tighten up the turnbuckles.

Stan