i'm currently building a timber garden shed, 2.4m x 2.4m x 2.2m high, most of the frame is 70mm x 70mm pine and the walls are 12mm thick structural plywood, i'm doing this job after building three very solid benches to sit pot plants on.
along the way i've had a few problems inserting the screws with the drill and now drill an appropriate pilot hole and insert by hand, a tough job no doubt about it but certainly more rewarding i have found
