new pole building on existing asphalt driveway that sits on a retaining wall
I recently purchased an old garage I want to convert into a pole building.I have an asphalt driveway with a large pad on it but the back side of it has a retaining wall that is about 6 feet tall. Question 1: how far away from the edge of the wall should I drill for posts to avoid the gravel backfill and drainage tile at the bottom, or do i not need to worry about hitting the edge of the gravel? Question 2: I also assume I need to go at least as deep as the wall is tall to hit virgin soil but I am not sure if that is deep enough or if I should go a little deeper to really plant it well.
All comments are appreciated,