What Are the Grades of Plywood and What Do They Represent?

Plywood is an engineered wood that is fundamental to many home building projects because of its strength and low cost. Understanding the different grades of plywood is crucial to choosing the best material for the task.

Plywood Grades: Softwood

In the case of softwood plywood, each veneer contains two grades, one for the "face" veneer and the other for the "back" veneer. There are four types of plywood veneers: A, B, C, and D.

• Grade A plywood is the highest quality. While it will cost more, the time savings for projects that are visible to the eye may be worth it. This type of plywood is smooth and easy to paint.
• Grade B plywood often has minor imperfections that may require minor repairs. A little less smooth.
• Grade C plywood has more visible defects and knots up to 1.5 inches in diameter.
• Grade D plywood can have large imperfections and knots up to 2.5 inches in diameter. This is usually the cheapest plywood veneer grade.
  The first letter denotes the grade of the plywood face, and the second letter denotes the back. Therefore, “AB” plywood will have a grade A face veneer and a grade B backsheet.

Plywood Grades: Hardwood

• The grading system for hardwood plywood is slightly different. Like softwood, the face veneer is represented by letters, with A being the highest quality and D the lowest. But there is a different standard for ridges: 1 is the best and 4 is the worst.
• A1 Hardwood plywood represents the highest quality plywood and D4 represents the lowest quality (but most cost effective) plywood.