i wont even try to mess with anchoring it to the rock, most of the places the poles are on the rock were crazy, the rock would be wedge shaped, so the pole would be sitting on a ^, so i had to pour concrete in the hole to fill in the void between the point ^ and the soil, so if i drilled, it would be into just a few inches of quickrete, if there was just some other dang way to anchor that one side down, i would be ok, but i have the metal roofing coming in this week and have absolutely no place to store it except out in the yard and i cant afford to have it stolen, so i want to get it on the roof sunday, but without the building being anchored, im afraid of getting one of those spring Tennessee storms and high winds getting up under the roof and picking it up like an umbrella, ive heard too many stories on this board about barns being blown out into the street and stuff...i do have a 8x10 porch i built that has a roof and is freestanding and not connected to the house that has never moved, even through storms, but the house probably blocks a lot of that wind, so..at this point, i wouldnt mind taking the trusses off and taking the whole thing apart and selling the lumber..lol..things went from going good to hopeless in about 2 days, between this concrete/anchoring thing and the gable overhang.