What size of plywood are used for roof decking?

Answer 1

The most common varieties of softwood plywood come in three, five or seven plies with a metric dimension of 1.2 m × 2.4 m or the slightly larger imperial dimension of 4 feet × 8 feet. Plies vary in thickness from 1/10" through 1/6" depending on the panel thickness. Roofing can use the thinner 5/8-inch plywood. Subfloors are at least 3/4-inch depending on the distance between floor joists. Plywood for flooring applications is often tongue and grooved. The mating edge will have a "groove" notched into it to fit with the adjacent "tongue" that protrudes from the next board. This keeps the boards from slipping past each other providing a solid feeling floor when the joints do not lie over joists. Tongue & groove flooring plywood is typically 1" in thickness.

Sources--

http://en.wikipedia.org/wiki/Plywood

Answer 2

Most of the time it will be 3/4". On a custom build we use 1 1/8 tongue and groove plywood or 2 x 6 pine #2 tongue and groove.

Actually, sub flooring plywood, T&G (tongue and groove) is 29/32". Almost 1".

Answer 3

As a standalone question I'd have to say there is no answer. In general. regardless of whether a piece of plywood is standing vertical or laying horizontal, the term "tall" doesn't typically apply. The dimensions commonly used to described plywood, and panel products as a whole, are width (W), length (L) and thickness (T). For plywood, or any "grained" panel product, the "L" is measured "with" the grain, the "W" is measured "cross grain"; thickness is self-explanatory. Additionally, the standard method of describing panel size follows the common construction practice of W x H, where H (height) and L are used interchangeable, then x T. So ... a 4x8x3/4 sheet of plywood would be 4 ft wide by 8 ft long by 3/4 of an inch thick. Plywood comes in many different sizes, but 4x8 is by far the most common. Also, plywood sizes tend to come "NET", that is a 4x8 sheet of plywood is 48" x 96", where as composition panel products (i.e. particle board, MDF, etc) are quite often "over sized; for example ... a 4x8 (nominal) sheet of particle board is typically 49" x 97".

Answer 4

Usually it's 4'x8'.