Types of Plywood – Hardwood plywood (often simply referred to as ‘plywood’) is a type of wood that is actually manmade – so technically it is not actually a natural wood, but rather is an engineered wood product.
Plywood is made by sticking three or more boards (veneers) of wood together with some sort of adhesive. The explanation does not need to be much more complicated than that.
However, it is important to know the differences between types of plywood, so that you can make a more informed choice when purchasing furniture, building materials or other plywood products.
A. Types of Ply
The term “ply,” as it refers to plywood , means the layers manufacturers use to create the boards at various thicknesses. Some projects won’t need a thick board, while others will. Ply achieves the right depth and can also make the boards stronger.
The thickness of the plywood (how many sheets are glued together) is known as the plywood grade. Each layer is known as a wood veneer. A veneer is a thin sheet of wood that you can glue together to create a different number of plies. Plywood, then, is the finished product when the manufacturer glues the veneers together.
It’s important to note, though, that veneers can also have various thicknesses. Depending on your location, some parts of the home must meet specific standards for the number of plies required for a board of a certain depth, especially with external walls and roofing.
1. 3-Ply
3-ply is one of the most common types of plywood. This kind has three layers of veneer and is layered enough to be strong and durable but can look more decorative than plywood with more plies, making it a good choice for indoor use.
2. 5-Ply
5-ply pieces of wood have five layers of veneers. This is another common type of plywood used for projects that require less durability and strength than those needed for exterior use.
3. Multi-Ply
Multi-ply plywood is mostly for exterior use and roofing. It can comprise several veneers, usually seven or more, to create an incredibly strong, unyielding frame for a home that can stand up to wind and damage.https://c102319dde3264ef0e153bfb0f1db3a5.safeframe.googlesyndication.com/safeframe/1-0-38/html/container.html
B. Types of Plywood
The various types of plywood you’ll find in the hardware store can make your shopping trip seem overwhelming but understanding how they differ is the key to deciphering what the best kind is for your project.
1. Softwood
Softwood is a type of plywood that manufacturers make using softwoods, like pine, redwood, or cedar. Some examples of softwood plywood are:
- Cedar plywood
- Redwood plywood
- Pine plywood
Although the name implies that these woods aren’t as strong as others, you might be surprised to know that construction workers typically use softwoods for exterior frame sheathing, roof sheathing, and sub-flooring.
Softwood plywood can also create things like sheds, temporary flooring, doghouses, shelving, and more.
2. Hardwood
Hardwood plywood typically has between three and seven layers and uses hardwoods. Manufacturers glue the layers of wood at right angles to one another to create an incredibly strong finish.
- Birch plywood
- Oak plywood
- Maple plywood
- Walnut plywood
- Poplar plywood
Hardwoods are best for things like furniture, packing cases, sporting equipment, musical instruments, and other intricate projects that require strong frames.
3. Aircraft plywood
According to Woodwork Made Easy Aircraft plywood is among the highest-grade, most durable kind you can find. This wood uses hardwoods, like mahogany or birch, to create an incredibly strong finished piece that can also resist heat and moisture.
The design incorporates some very thin veneers that can keep it light and flexible, while still giving it unyielding strength for the heftiest jobs. You’ll find this type of plywood in projects that need industrial-strength woods, like airplanes, boats, and furniture that’s meant to hold a lot of weight.
4. Exterior plywood
Exterior plywood has weather and water-resistant glue that holds each veneer together. When you create an exterior with plywood, one of the biggest – and most important – concerns is how the wood will handle wind, rain, and other weather. Exterior wood is meant to combat the elements to provide a strong, sturdy frame for years to come.
Exterior plywood sheets typically have several veneers glued together, classifying them as multi-ply. You can also choose various kinds of wood for exterior plywood, depending on the area in which you live. Some locations that experience unusually harsh seasons may fair better with wood like oak, which can resist mildew and mold from damp conditions.
5. Lumber Core
Source: Schaller Hardwood
Lumber core plywood is usually made with three plies, with two thin veneers on each side and a thick core. The outer veneers are typically made of a hardwood, while the inner core consists of strips of wood glued into one solid slab.
The inner core helps grasp screws, which makes it a good choice for projects that need a strong screw hold. One disadvantage is that poorly-made lumber core plywood may have voids within the core that diminish its strength and screw holding abilities.
6. Marine plywood
Source: Timber & Building Supplies Online
You might think that the name of marine plywood , also known as marine-grade wood indicates that it’s waterproof, but that’s not the case. Instead, wood manufacturers make marine grade plywood with water-resistant exterior glue using the same layered construction as other woods.
The difference is in the grade of marine types. According to the APA – Engineered Wood Association, marine-grade wood consists of Western Larch or Douglas Fir woods and must have a B-grade or better, which we’ll discuss in the “More Details” section of this guide. This kind of wood is one of the best-constructed, high-graded plywood on the market.
Marine-grade wood isn’t resistant to mold, mildew, or rot from weather and water. Manufacturers don’t treat it with any chemicals, so rot and decay can be a problem unless you treat it with a pressure-preservative, as suggested by the APA.
To be graded as marine-grade, this wood must have no knotholes in any of its plies and use a top-performing water-resistant glue between plies. This ensures that the glue won’t stop working if the wood becomes damp from weather or wet conditions.
You’ll see marine-grade woods used mostly on outdoor furniture and decorative pieces, like gazebos, planter boxes, and benches.