7 16 will be fine for 16 on center and 5 8 for 24 on center rafters.
Osb for shed roof.
However there are some sceptics out there who doubt the strength and durability of osb.
Standard asphalt shingles do an excellent job keeping the weather out.
Underneath the shingles is osb sheathing.
For the curious 7 16 osb has a span rating of 24 16 and with supports every 24 inches is good for a roof live load of 40 psf pounds per square foot with a 10 psf dead load.
With edge support and the same snow load 3 8 inch osb can be used.
Good enough for houses good enough for a shed.
The osb thickness will be based on the rafter spacing.
Thicknesses range from 5 16 to 3 4 inch and the proper one to use.
However moisture has a way of finding its way into a structure.
Sheets of 7 16 inch thick with no edge support can be used in an area where the snow load is 30 pounds per square foot.
Plywood with similar propertiescurrently costs about 30 more for an equivalent thickness.
Using oriented strand board is a tested way of reducing costs for building your shed.
Typical types of wood used for roof sheathing are oriented strand board known as osb and plywood the most popular being osb.
Osb comes in 4 by 8 foot sheets as does plywood but the manufacturing process allows the production of longer and wider ones.
Using oriented strand board osb for shed walls floors and roofs.