If you have a couple bucks and only intend on running 100W, a wide range auto tuner feeding a loop would work pretty well for you.
SGC-237, stuck in a Tupperware bin, tucked up under an eave as the tuner, then run wooden poles just a few feet off the roof at each corner and feed wire in a loop around the roof. Bring both ends of the wire, stood off from gutters etc, down into the SGC-237 auto tuner.
You could do this same thing, more effectively even, if you run a manual tuner like a Palstar AT1KP feeding window or open line up to the feed of the loop. That would hold power that way too, good few hundred watts at least.
You'd be able to work reasonably well on any band where the loop was a full wavelength on up in frequency from there. You might be able to get it to play on the next lowest band as well, but losses go up from there.
The other alternative to consider if you have the reach on your property is an end-fed wire with a manual tuner fed against a ground rod with some radials on it. Make the wire a half wavelength or longer for the lowest frequency band you want to work.
Yet another idea is a vertical up on the roof, like a GAP Titan as it requires no radials and will work pretty well from 40m on up...80m on it is pretty useless.
G5RV as mentioned, by its design will be pretty awful lying on a roof. The fan dipole or resonant dipoles would be a lot better than a G5RV for that.
Any antenna that close to the house will pick up a lot of noise from appliances and power supplies inside the house. Of course interference inside the house goes way up with the antenna so close too.
SGC-237, stuck in a Tupperware bin, tucked up under an eave as the tuner, then run wooden poles just a few feet off the roof at each corner and feed wire in a loop around the roof. Bring both ends of the wire, stood off from gutters etc, down into the SGC-237 auto tuner.
You could do this same thing, more effectively even, if you run a manual tuner like a Palstar AT1KP feeding window or open line up to the feed of the loop. That would hold power that way too, good few hundred watts at least.
You'd be able to work reasonably well on any band where the loop was a full wavelength on up in frequency from there. You might be able to get it to play on the next lowest band as well, but losses go up from there.
The other alternative to consider if you have the reach on your property is an end-fed wire with a manual tuner fed against a ground rod with some radials on it. Make the wire a half wavelength or longer for the lowest frequency band you want to work.
Yet another idea is a vertical up on the roof, like a GAP Titan as it requires no radials and will work pretty well from 40m on up...80m on it is pretty useless.
G5RV as mentioned, by its design will be pretty awful lying on a roof. The fan dipole or resonant dipoles would be a lot better than a G5RV for that.
Any antenna that close to the house will pick up a lot of noise from appliances and power supplies inside the house. Of course interference inside the house goes way up with the antenna so close too.