For all of you inquiring minds out there , in Indiana they call Wood shingles "Shakes". We don't really nail asphalt shingles over shakes, altho the roofers here will tell you that we do :blink:
Holy shit, tell me you and your men are not just standing on that mansard with nothing beneath you! We would set scaffold frames to the bottom so that we had somewhere to drop the debris, and also a place to work from for safety's sake at least.
In the end, it is much faster and a whole lot cheaper than trying to train a new roofer to replace the one that was killed falling off the roof!