I built my shed about 20 years ago and used 3/8" spruce ply roof sheating on 16 inch centers. The guys at the "Borg" said that's what everybody uses - it meets code. Well, meets code doesn't mean squat. The shingles have needed replacing for a few years now - no leaks, but starting to curl along the one edge - and I noticed the roof looked a bit wavy.
After stripping the shingles, "a bit wavy" was definitely an understatement. It looked like a windy day on Lake Superior.
The "Borg" only had spruce ply sheathing and termite spit, so I went to the local Home Building Center, which had spruce listed, but on the racks it was DFP - Douglas Fir Ply. NO comparison!!! I bought 5/8 tounge and groove and screwed it dowm. My first attempt was with "construction screws" from the Borg. Drove in 20, and broke 15. Took the remaining 330 back, and replaced them with the much cheaper "deck screws" - same price for 500. I can drive them right down through the plywood without breaking them. The person at the return desk gave me $15 discount for the trouble - Their products might be crap, but at least the service is good - -
Now I just have to get my eave starter strips on and get shingling -
- - . Lots of help from my future son-in-law, andmy daughter even helped me get the first sheet up this evening.