Behind the cherry, birch, or maple doors of a kitchen cabinet is the wood used to construct the cabinet box—the back, sides, top, shelves, and bottom. There are usually two options for cabinet box construction: plywood and particle board. Plywood is made up of layers of wood veneer glued together, alternating the grain of the wood for stability. Particle board (also known as furniture board) is made of wood fibers glued and pressed together, sometimes using a mold. Each material has benefits to consider.
Plywood is generally thought to be the better product when building cabinets. Plywood has superior construction longevity because it holds screws and other mechanical fasteners more efficiently. It has superior tensile and shearing properties (meaning it resists pulling forces and side-to-side movement) and a slight advantage in compressive strength (ability to bear weight), said Paul Kiefer, BBR staff member who has 20 years of experience as a woodworker. Plywood also weighs less than particle board, which can be significant when hanging large cabinets. In addition, plywood holds glue joints together better than particle board and is more resistant to dents and scratches.
Particle board has its own advantages, including greater dimensional stability: it does not warp due to temperature fluctuations and other changes in the environment. Most notably, particle board costs less than plywood. Particle board is often made of scraps of wood that are considered waste. Many plywood manufacturers also make particle board from the leftovers. Because of this, particle board is less expensive. By using particle board, one can save between 8% and 12% on the cost of cabinets, said Boston Building Resources kitchen designer Linda Lesyna. Among BBR’s cabinet lines, particle board is available as an option from Candlelight, Executive, Imperia, and Purekitchen.
A major downside to particle board is its lack of moisture resistance. If moisture is absorbed through the end grain, particle board will swell—for example, if water on the floor comes into contact with the unfinished bottom edge of a cabinet box. To address this potential problem, Imperia seals the ends of all particle board pieces with edge banding. The installer may also seal the bottom edges of cabinet boxes with a clear coat when installing them. Plywood, though more water resistant, is also not very durable in continually wet conditions.
Importantly, plywood and particle board can vary greatly in quality, making it hard to say that one is always better than the other. The quality of plywood depends on the number of plies and the thickness of the wood. Fewer plies are less stable, so quality plywood will have more plies. The quality also depends on how well the plies are glued together. Low-quality plywood will have gaps, making it less reliable. Plywood used for frameless cabinetry usually has between seven and nine plies and a thickness of 3/4 of an inch, Linda said. For face-frame cabinetry, half-inch plywood is used for the sides, top, and bottom because the frame adds strength to the overall box structure; shelves are 3/4 inch plywood. So, though plywood is superior in general, there are many cases where particle board will perform well enough to justify the cost savings, says Linda.
Particle board quality depends on the size of the particles that make it up, the glue that holds it together, and the density of the board. Because particle board can be made out of a lot of wood waste, its quality can vary quite a bit. Smaller particles make the board better quality, denser, and heavier. One of the best kinds of particle board is medium density fiberboard (MDF), which is high quality, but can be very heavy, making it difficult to hang large cabinets. Particle board is also easily gouged or scratched; however, this is not as much of an issue if it is protected by wood veneer or laminate.
Because plywood is superior to particle board in many ways, it is usually the better choice if cost is not an issue. However, the fact that particle board is less expensive makes it a reasonable choice in many situations. If the cabinet is large and going to be hung, plywood may be the better option because it is lighter. In most other situations, particle board will work almost as well as plywood. When renovating, be sure to consider the benefits of plywood against the limitations of your budget to decide which choice is best.