As a professional framing contractor, I would like to share one of my house framing tips with you. Most plans require half-inch plywood or oriented strand board as their roof sheeting. This product is fine and if you’re building a lot of homes, you’re not going to have the choice. Ordering larger sized plywood could cost you thousands of dollars, especially if you’re building a lot of homes.
However, if your framing or building a home for someone or even yourself, you might want to take my advice and think twice about it, before ordering the roof sheeting. Half-inch plywood, works okay for 16 inch on center roof rafters or engineered truss roofing systems. It doesn’t work well on 24 inch on center roof rafters spacing.
It is usually flimsy and weak at the center point, directly in between the 24 inch roof rafter bays. If you’re going to use the half-inch plywood, I would recommend using plywood clips that are relatively inexpensive and can be placed in the direct center of each roof rafter bay on each sheet of plywood. These can be purchased at most home improvement centers or lumber yards.
The other alternative, and this is what I recommend, would be to use 5/8 inch plywood. This plywood works great for 24 inch on center roof rafters and you will have a nice sturdy roof to walk on, while roofing your home.
I have actually seen people step through the flimsy plywood, while lifting heavy roof tiles and bundles of composition roof shingles. Experienced roofers try to walk directly on top of the roof rafters, when loading their roof shingles or even carrying them on the roof.
If you’re a home builder and your concern is about making a profit, you will need to use the half-inch plywood. If you want to build a superior roof, use the 5/8 of an inch plywood.