7 16 will be fine for 16 on center and 5 8 for 24 on center rafters.
Osb for shed roof.
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.
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.
With edge support and the same snow load 3 8 inch osb can be used.
Plywood with similar propertiescurrently costs about 30 more for an equivalent thickness.
Typical types of wood used for roof sheathing are oriented strand board known as osb and plywood the most popular being osb.
Good enough for houses good enough for a shed.
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.
Osb is fine all the way around.
Underneath the shingles is osb sheathing.
However there are some sceptics out there who doubt the strength and durability of osb.
The osb thickness will be based on the rafter spacing.
Using oriented strand board is a tested way of reducing costs for building your shed.
Osb comes in 4 by 8 foot sheets as does plywood but the manufacturing process allows the production of longer and wider ones.
The thickness required by josh s circumstances are good for roof snow loads of up to 70 psf again spanning 24.