Plywood is an affordable wood for any project. However, if you browse a home improvement store, you may be overwhelmed by the options. Between the number of layers to the different types and everything in between, here’s everything you need to know about buying the right plywood for your projects.
What is Plywood?
Plywood is an artificial wood that’s used in different building projects. It’s made by adhering different boards or veneers together, including 3-ply, 5-ply, 7-ply, 9-ply, and 13-ply. How thick it is impacts the grade of the plywood, among other properties, and what it is used for.
For example, 3-ply is the most commonly used type of plywood for indoor projects. At the same time, multi-ply (5-ply or more) is best for exterior use, including roofing. You must choose the correct grade based on the project.
Types of Plywood
Plywood varies not only by grade but also by the type of wood used. You’ll want to select the correct type of plywood for your project.
Softwood plywood is most commonly made using cedar, redwood, and pine. Don’t let the name fool you. It’s most often used in sheathing exterior framing, roofs, and sub-flooring. Softwood is also used to create select external structures like sheds, doghouses, shelving, and temporary flooring.
Hardwood plywood is often made using birch, oak, maple, and walnut. Its grade is typically between 3- and 7-ply. Hardwood plywood makes incredibly strong frames, so they are best for making musical instruments, furniture, packing cases, sporting equipment, and other complex projects.
Exterior plywood is weather and water-resistant, making it excellent for outdoor projects. It’s often made of Douglas fir or oak, held together with glue designed to withstand all weather conditions. These woods are mildew- and mold-resistant, extending their lifespan when exposed to the elements.
Lumber core plywood is typically 3-ply, with two thin veneers covering a thick wood core. The dense core helps to hold screws, but if it’s poorly made, there may be voids that lessen its strength over time. It’s typically made using Basswood.
Marine plywood often uses western larch or Douglas fir to create its sturdy construction. It is one of the highest-graded and best-constructed plywood that you can get on the market today. While the glue is water-resistant, the wood itself is not treated. This means that, despite its name, your Marine plywood is not resistant to the weather, including water, and may be susceptible to rot, mold and mildew over time.
Overlaid plywood has a finished surface that makes it great for quick and dirty projects. The finished coating helps the plywood be water-resistant, scratch-resistant, and fade-resistant, which is especially important during transport. High-density overlaid boards are more expensive than medium density and feature more resin. Both thicknesses are strong and durable.
Structural plywood is among the lowest grade plywood; it’s not designed to look good. Instead, structural plywood is made to be strong, to frame and build structures that will be covered. Use a strong adhesive to keep the boards together. They are not weather resistant, so be careful with outdoor use, even when it’s covered.
Aircraft plywood is very durable plywood thanks to its high grade. It’s typically made using mahogany and birch wood, making it resistant to heat and moisture. Aircraft plywood is used in industrial-strength projects, including airplanes, high-capacity furniture, and boats.
In addition to those listed above, there are other types of plywood that you can use depending on your project. These include commercial, composite, sanded, veneer core, flexible, tropical, decorative, and MR-grade plywood.
In recent years, builders have used other types of boards in the place of plywood. They can be less expensive, but you’ll want to ensure that they are strong enough for your project. Consider composite woods, blockboard, foamboard, fiberboard, hardboard, particleboard, and more for your projects.
The type of plywood is not the only factor you want to consider when picking the right plywood for your project. You’ll also want to consider the grade, size, and finishing.
Plywood is graded, so you know the best places to use it. The higher the grade, the better it is for outdoor use or projects that require extra strong materials. Look for A-B or A-C for projects that will be exposed to various weather conditions. Look for plywood with an X at the end for additional peace of mind. That means it has met the rigorous standards for outdoor use.
C-D-graded plywood can be used indoors, but you’ll need to finish it with other wood or coverings. You’ll also want to keep an eye out for knots and voids in the wood. It will impact how the plywood stains.
Plywood not only comes in different thicknesses but also different sizes. Make sure to choose the correct width and length for your project right from the start. Thin sheets will be more flexible, while thicker sheets will be stronger. If you don’t find a short enough sheet for your needs, you can always cut them to size at the store or later at home.
Depending on what you’re using the plywood for, you may need to finish it. If the board has knots or other imperfections, they will be visible, even after you stain or treat the wood.
The Final Word on Plywood
Plywood is a great building material, and when you know what you are working with, it can help provide the framing and structure to build your next big project. Consider the type, material, grade, size, and other features before selecting the plywood best for you. Your budget may constrain you, but you can find a type of plywood that works for you.