Revisions log for Answer #1288

We usually level with plywood. We cut plywood pads of 4.6 and 8 mm, you can dial in 2 mm increments. If it's not possible to level the rafters themselves. We make a counter-batten, and then along the outermost rafters we stretch strings, make pads under each batten along the outermost rafters. Then pull the string across, beat the rest, beat the battens, pull the next, padding, battens, etc., it turns out pretty quickly.