Plywood is a necessity for many projects, from building cabinetry in the laundry room to building your dream gazebo in the backyard. However, if you’re not an experienced plywood shopper, the numerous options at the hardware store can seem overwhelming.
You’ll find various prices matched with multiple materials, ply, sizes, veneers, grades, and more. Our ultimate guide to different types of plywood and the projects for which they work best should help you narrow your options to find the right kind for your needs.
Table of Contents
- I. Plywood Buying Guide
- A. Types of Ply
- B. Types of Plywood
- C. Other Types of Boards Often Used as Plywood
- II. More Details
- III. Where to Buy Panels Online
I. Plywood Buying Guide
A. Types of Ply
Source: Workshop Supply
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.
Each layer is known as a wood veneer. A veneer is a thin piece 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.
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.
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.
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.
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.
Softwood is a type of plywood that manufacturers make using softwoods, like pine, redwood, or cedar. 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.
Hardwood plywood typically has between three and seven layers and uses hardwoods, like birch, maple, oak, and walnut. Manufacturers glue the layers of wood at right angles to one another to create an incredibly strong finish.
Hardwoods are best for things like furniture, packing cases, sporting equipment, musical instruments, and other intricate projects that require strong frames.
Source: Spitfire Aircraft Company
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.
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.
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 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.
7. Overlaid Plywood
Source: Piano Plywood
Overlaid plywood, which can be either high or medium density (HDO or MDO), is a kind that utilizes the same structure of regular sheets with veneers glued to one another. However, overlaid sheets have an overlaid face that gives it a somewhat finished appearance.
The finished exterior isn’t necessarily for decoration, but instead gives the panels a durable surface that’s also smooth enough to keep water and other particles from damaging or sticking to it. The coating also helps the wood resist scratches and other abrasions that may happen during transport and construction.
Manufacturers bond the exterior surfaces to the rest of the veneers through a process of heat and pressure. High-density overlaid panels have more resin than medium-density panels, making them a bit more expensive. However, both can make a finished project stronger and more durable than can traditional plywood.
Source: Bunnings Warehouse
Structural plywood, also known as sheathing plywood, is not for looks, but rather, strength for framing and building structures in which you’ll eventually cover the wood. This type of wood needs a very strong adhesive to keep the plies together.
You can use structural woods on the inside or outside of a building, but they aren’t typically as weather-resistant as other types. Structural woods usually have a C or D grade, but no higher, so they’ll be an inexpensive option compared to some woods, but they also may not have the high performance you need for outdoor structures.
C. Other Types of Boards Often Used as Plywood
There are some other types of wood board that people use in place of plywood. Although they aren’t technically classified as plywood, you can use them in many similar instances.
Some of the following alternatives can provide inexpensive options for those on a budget, while others can create a completely different finished look for your project.
1. Composite Woods
Source: Columbia Forest Products
Composite woods come in similar sizes as traditional plywood, but manufacturers don’t make them quite the same. They do use layers, but composites have regular wood layers on the inside and external layers that consist of fiberboard covered with a layer of hardwood.
The construction leaves the outside smooth and easy to work with, while the strong core gives the wood a durable and unyielding frame. You’ll find composite wood mostly on furniture and cabinetry.
Source: Piano Plywood
Blockboard uses a similar construction as plywood, usually with three layers. The inner core has thick, square cuts of wood that are glued together to create the strong core. The outer layers are thin and enclose the wood, forming a thick piece of wood.
Sometimes, you’ll see finished outer layers for cabinetry and other furniture pieces on blockboard. While plywood is a good option for surfaces that need a strong surface, blockboard is more about the core and a decorative finish. Blockboards usually range in thickness from 3/8-inches to 1 3/16-inches.
Source: Boulter Plywood
Foamboard has become more popular in recent years, offering a rot-resistant alternative to plywood. These boards have a reinforced polyurethane foam construction that is reinforced with fiberglass, creating a board that’s just as strong as plywood, but also offers extra protection against mildew, mold, and rotting.
Foamboard can also be significantly lighter in weight than plywood, even in the densest boards.
The most common type of fiberboard is medium-density fiberboard, also known as MDF. This alternative to plywood consists of engineered wood fibers glued together to create a dense composite. You can find either hardwood or softwood MDF, or a combination of the two.
The benefit of this type of wood is that the small fibers create a finished piece without knots or rings. Unfortunately, you also won’t see the wood grain, which can be a drawback for people who want that authentic wood look for their furniture or other finished product.
MDF is a less expensive alternative to plywood, but is stronger than the least costly options, like particle board. Still, you might end up with cracks or split wood as you work because MDF won’t be able to handle a lot of stress.
The finished product is easy to cut and paint. Additionally, you don’t have to worry about splinters as you work because MDF’s dense construction results in a smooth finish.
Hardboard is a thin piece of fiberboard that often has one side rough and the other finished. Manufacturers use wood pieces to create hardboard, which then gets densely compressed to make a panel that doesn’t bend or warp.
Hardboard is exceptionally durable, despite its thin frame. It’s common to see this type of panel on kitchen countertops, furniture frames, and subflooring. Some people use hardboard for the base of their laminate flooring because it’s so strong and can stand up to constant wear and tear.
Particleboard is one of the least expensive alternatives to plywood. Particleboard has no layered construction. Instead, it’s comprised of small slivers of wood scraps glued together to create a board. This is the type of material you usually find on inexpensive furniture pieces.
Particleboard may be cheaper than plywood, but it’s also much less durable. This type of wood can split and crack easily, and it’s not uncommon to hear about pieces breaking during assembly of particleboard products. You’ll also notice that particleboard is much heavier than plywood, making assembled pieces more difficult to transport.
One of the biggest issues with particleboard is that, in its regular form, it’s untreated, so it’s susceptible to swelling if it’s in an area with high moisture. If you’re going to use particleboard, you should ensure that you seal it correctly to avoid warping and swelling.
7. Moisture-resistant Particleboard
Moisture-resistant particleboard has the same construction as regular particleboard, except that manufacturers use a particular moisture-resistant resin to keep the board from swelling and warping in wet areas.
You’ll be able to tell the difference between regular particleboard and its moisture-resistant version by the color of the board. Moisture-resistant boards usually have a green dye added to the resin to make them distinguishable.
II. More Details
Now that you know more about the various kinds of panels you’ll find, you’ve probably decided on the right type for your project. However, there a few more essential details can help you narrow your options further. Let’s look at the different materials, finishes, sizes, and grades of plywood that you’ll come across as you shop and how it all translates into the right kind for your job.
A. Wood Grades
We’ve mentioned the grades plywood sheets can have a few times in this article. It’s important to understand why wood has a grading system and what the grades mean for the type of wood you purchase.
The plywood grading system uses letters A, B, C, and D, with A being the best and D being the lowest quality. You’ll see two letters, though, for most woods. One letter designates the grade for the front of the board while the other grades the back, or the part you won’t see when you install it. Typically, one side will have a lower grade than the other, and that’s the side you’d want to use in the back.
Exterior panels will usually have high grades of A-B or A-C. You’ll want to ensure that you choose the highest grade possible for anything that may be exposed to weather or needs excellent strength. A grade of C-D is usually okay for internal structural use but isn’t something you should consider using if it won’t be adequately covered. You might sometimes see an additional grade with an X at the end, like A-CX. This just means that the board has met the standards for external use.
For projects that require a high-end finish, opt for higher grades. These should have little to no knots and voids and should provide a nice, smooth finish for staining or painting.
B. Sheet Sizes
Plywood comes in several different thicknesses, widths, and lengths to meet the needs of your project. Some sheets are so thin that they’re flexible enough to bend over structures to form a uniform shape, while others are incredibly thick, made to withstand things like weight and wind. Sheets can be very long, but you can usually ask a hardware store or lumber yard to cut the sheets to the measurements you need.
The size indicated on the panels may not be the exact size, though, which is important to remember when picking up the sizes you need for your project. A ¾-inch piece of plywood, for example, actually measures 23/32-inch, which is crucial to take into account when you plan your project since a 1/31-inch gap won’t be very attractive in most pieces.
Some lumberyards also tag their sizes in millimeters rather than inches, which can further complicate your shopping. Be sure to have your phone with you to do a quick conversion using Google or a mobile app so that you can make sure you have the correct size.
We discussed several how hardwood and softwood boards differ and what types of wood qualify as hard and soft. But, what differences will these woods bring to your project? Interestingly, scientists classify hardwoods and softwoods by their trees’ seeds, not the actual density or strength of the wood itself.
However, they do perform slightly differently in woodworking, but mostly in the way that you cut them. You can usually cut softwoods a little more easily than hardwoods, but hardwoods may be able to outlast softwoods in furniture, flooring, and other parts of the home that are subject to wear and tear.
You might prefer the look or feel of one type of wood over the other when it’s made into a sheet of plywood. Your best bet is to look at all the options and feel them. You might even prefer the feel of one over the other which can help you decide on the best kind for your project.
Remember, though, that hardwoods can be more expensive than softwoods. Softwoods tend to be more common and available, so they may not eat into your budget as much.
D. Finishing Plywood
If you don’t want to cover up your wood panels, and instead want to stain or paint them, you’ll need panels that provide the right surface to do so. High-grade panels, those marked with A or B are the best type to use for finishing. If you want to finish both sides, you’ll need to make sure that both letter grades are A or B.
To paint almost any plywood, you should plan to use a primer first, which will give the wood a smoother surface and help the paint adhere to it. You’ll probably need at least two coats of paint to give the wood the right finish. Painting with a brush may help you penetrate the wood better, which will require fewer layers.
If you’d like to stain the wood instead, choose smooth plywood, or you’ll find it difficult to create an even finish with the stain. Allow the stain to dry for at least 24 hours before coating it with a clear varnish, which will help protect the stain and seal your wood.
With both paint and stain, you should consider using a sealant as the last step to prevent molding and rotting in the wood when exposed to moisture.
III. Where to Buy Panels Online
Buying panels online can be a little tricky because you can’t see the pieces you purchase in person, leaving you to guess whether you’re getting an adequate piece without voids and numerous knotholes. However, the following online stores are ones that we recommend if you’d prefer to shop for plywood online than in the store:
Do be careful to only purchase from trusted suppliers on Amazon and when you aren’t buying directly from Lowe’s or Home Depot. Research the company first before finalizing your order to get an idea of the quality and grade of woods it sells.