How Plywood is Composed
Check out the differences between oriented-strand board and plywood.
Know Plywood Grades
- 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 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 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. Used for projects like 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 back side 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.
Know Which Kind of Plywood you Need
Plywood for Roofing
Plan your Project
It’s What’s Inside that Counts for Plywood
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.
Look for Non-stained Plywood
Find out how to build floating shelves, which can also be made from plywood.
More Layers Doesn’t Equal High Quality
Don’t Forget the Edges
Learn some tips on cutting plywood.