Use plywood to complete a range of DIY projects, from subfloors to furniture
Plywood is ideal for applications in residential and light-duty construction and is made from thin sheets of veneer that have been peeled from debarked wood. These thin layers, also called plies, are glued together in alternating, perpendicular directions to create a cross-graining pattern. This pattern results in added strength and stability that resists shrinkage and expansion, should it come in contact with moisture.
Plywood is an engineered wood from the manufactured boards family, which also includes particle board and oriented strand board (OSB). The types of wood species that are used in engineered plywood include ash, oak, birch, maple, cedar, spruce and pine.
This guide will walk you through the different uses of plywood, as well as explain its rating and grade system.
Plywood is a popular choice in construction because of its low cost. It is usually used in areas that are hidden from view in a post-construction capacity.
The most common uses for plywood include support for floors, walls, roofs and garages in residential construction.
When used for roofing, plywood panels are covered and protected by a variety of building materials that keep the elements at bay, including roof felt, underlayment, flashing and shingles. When used in flooring, plywood functions as the subfloor that supports hardwoods, tile and carpet floors.
Plywood makes up the majority of the walls and floors in attics, and are sometimes found in laundry rooms, closets and other unfinished areas in the home. It can also be made into fencing materials, packaging materials, scaffolding, shelving, sheds, shipping containers, cabinets and furniture.
Ratings, Grades & Sizes
Plywood is sold in various ratings, grades and sizes. Make your selection based on the type of project you’re working on.
There are two ratings that convey where and how to use plywood. The first rating is Exposure 1, which means the panels can withstand exposure to the elements during construction, but are not suitable for long-term exposure post-construction.
An Exterior rating means the panels have been waterproofed and are able to withstand extended exposure to inclement weather.
The Home Depot carries four grades of plywood: A, B, C and D. A is the best and most expensive, and D the least expensive.
A-grade plywood features a smooth, sanded surface without knots. Any wood defects have been repaired with synthetic filler, so the veneer can be painted, making it ideal for furniture or cabinet doors. B-grade plywood also features a smooth, sanded surface, but may have more repaired defects up to 1-inch across.
C-grade is unsanded and may have several minor defects that will need to be repaired with knots up to 1 1/2 inches across, discoloration and sanding defects. C-grade plywood should be used when appearance is not important, such as on subfloors or garages. D-grade is also unsanded with defects that have not been repaired and knot holes up to 2 1/2 inches across, discoloration and sanding defects.
You may also find ratings with two-letter classifications, such as BC. BC-grade is a mix grade plywood with one side graded a B, while the other side is graded a C.
The most common size for plywood sheets is 4 x 8 feet, followed by 5 x 5 feet. The Home Depot also carries pre-cut project panels that are available in different sizes that may vary by store. These project panels help eliminate waste, cut costs, and are easier to transport than full-size panels.
The most common thickness of plywood is 1/2 inch, but can range from 1/8 inch to 3 inches.