The Right Plywood for the Job

Plywood is made of several layers of veneer, thin sheets of wood sawed off from trees. The layers are glued together and if water-resistant glue is used, it is exterior plywood. Pine, spruce, mahogany, Douglas fir, birch, oak and maple are types of wood used for exterior plywood. Exterior plywood used the traditional grading system but uses the letter “X” to indicate it was made with exterior glue. We'll help you find the right plywood for you. Check out the differences between oriented-strand board and plywood.

There are a few plywood grading systems out there, but most of them follow an A-D classification with A being the best. Plywood is also classified as Exterior, Exposure 1, Exposure 2, and Interior. The type of plywood you choose will depend on economics, how much exposure to the elements the wood will get, and whether looks are important to you.

• Fully waterproof bond (glue) between the layers and designed for applications subject to permanent exposure to weather and moisture.
• Exposure 1. Fully waterproof bond but not for permanent exposure to weather or moisture.
• Exposure 2. Interior type with an intermediate bond. Intended for protected construction applications where slight moisture exposure can be expected.
• Interior applications only.

If you don’t have a lot of money to buy plywood and you don’t care if your plywood is baby smooth on the surface, go for a lower grade. It’s just as strong as the nicer looking grades.

• Smooth, paintable surface. Repairs to the veneer like replacing knots with patches can be made, but no more than 18. This is the best plywood for cabinets.
• Solid surface. Minor splitting permitted.
• Tight knots and knotholes allowed. Can also have discoloration and sanding defects on the surface as long as it doesn’t impair strength.
• Larger knots and knotholes permitted.

You’ll often see plywood with two grades as in “A-C.” This means that the face side is an A grade and the backside is a C grade. In addition to the above two classifications, plywood is also rated as Sheathing, Stud I-Floor, and siding. This just specifies what a particular end use a piece of plywood was designed for. Most of the plywood you buy from the hardware store for projects around the house like a workbench will be classified as sheathing.

The different grades of plywood indicate what it should be used for. Exterior grade plywood is for roofs or where direct contact with water is possible. You’ll want it to be pressure treated. For bathrooms, a Luan plywood is good to put on top of decking plywood for protection. Marine plywood is good for things that need to withstand water like boats. The best plywood for cabinets is decorative plywood and can also be used to make furniture. Create circular saw cutting guides for plywood.

Plywood for roofing typically needs to be 3/8” but using thicker plywood can mean more durability. Check your local building codes to see the requirements. Check out DIY shed building tips and how plywood was used.

If you need plywood for roofing, walls or subfloods, then choose construction plywood or OSB. Oak or birch hardwood is good for cabinets, storage and furniture. The Home Depot has a handy chart to make picking plywood easier.

Plywood comes in many forms but it’s also constructed in several ways so it can be tough to find the right plywood. Plywood cores vary greatly and include veneer core, particleboard core, medium-density fiberboard core and combination core. Veneer is the most common core type and is made of different trees depending on the region. It is also a lightweight option, weighing about 70 pounds for a 4x8 panel. Particleboard core (PBC) is usually the cheapest, weakest and heaviest. It can weigh 100 pounds for a 4x8 panel and can swell up with moisture. Medium-density fiberboard (MDF) is good for shelving and storage cabinets and the face is harder than most woods. However, its inner layers are soft. It will sag over time, though. Find out how to use melamine.

Sometimes stained plywood can hide imperfections under the stain so it’s best to find unstained plywood. Find out how to build floating shelves, which can also be made from plywood.

In general, it’s thought the more layers in plywood make it a higher quality. More plies can mean fewer voids in each veneer but the quality of the veneer core is certainly more important. Even plywood with many plies can still warp.

The face of plywood can be great for projects but the edges leave something to be desired. You can remedy that by using iron-on banding to cover up the layers of veneers.

Starts with the right blade, you can use a plywood cutting blade or use a blade you know will cut. Set the depth right and use some extruded foam as a backing board. That will prevent any kind of snapping off of the piece. Always cut with the good side down and along the scrap side so it won’t punch out or splinter. Learn some tips on cutting plywood.