My shed is insulated and vented and heated w/ a Rinnai and air conditioned too, but no plumbing to freeze up, plus it has a super lake-Gunstock mountain-Timber Island view....very nice shed..... it's a workshop.
Doing this roof job gives me a big appreciation for what roofing is all about. Surprisingly....make that very surprisingly, the 3/4" plywood roof was still solid despite the cruddy condition of the old shingles. The winter of Jan 2008 with all the ice was hard on this roof which has a low angle, not too steep pitch on one side.
Suggestion - How to be fully employed.....become a roofer....or is that a roofa......
.....yikes....hard work !