The Right Plywood for the Job
The world of plywood is vast and complicated but once you learn the grades you can find the right plywood for the job in a jiffy.
How Plywood is Composed
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.
Know Plywood Grades
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.
- 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.
Know Which Kind of Plywood you Need
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
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.
Plan your Project
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.
It’s What’s Inside that Counts for Plywood
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.
Look for Non-stained Plywood
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.
Don’t Forget the Edges
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.
Originally Published:August 20, 2019