Started tearing the old roof of the garage, which had been built by the previous owner of the property.
So far, after raking and sweeping off all the leaves and topsoil I could reach from a scaffold (I'm not _about_ to put my weight on the roof deck until I see what it looks like from both the top and the bottom) I started tearing off shingles on the shed part. Got on sheet of decking cleared and decided to take five and vent.
First thing, he used shingles on a relatively shallow slope. Next, along the edge for about two inches there's no deck, just shingles. Of course the shingles have long since failed so the ends of _every_ rafter are rotted. There's no sign of anything resembling an underlayment--no tar paper, no ice and water shield, no _nothing_, just shingles directly on plywood. Cheap shingles, thin as a piece of poster board. About 9/10 coverage (i.e. not even quite single coverage--I can see plywood between shingles in places). Each shingle got two and only two nails whether it needed it or not. Between two sheets of decking water's been coming down from somewhere higher up--it's rotted the ends of the decking, the top of the rafter, and the roof plate (may not be his fault--haven't gotten high enough to see where it was coming from yet).
That's one sheet of decking clear, 25 more to go.
The guy meant well, but every repair that he's made to the house so far I've had to redo to fix what he screwed up. Been better off if he's just left it alone.