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Plywood vs. MDF vs. Particleboard Cabinets: What Is in the Box and What It Costs You Later
Kitchen Cabinets
Plywood, MDF or Particleboard: What Is Inside the Box, and What It Does Under a Leaking Dishwasher
Doors are what you look at. Boxes are what you live with, and the box is the one part of a kitchen nobody puts in the brochure photo. Three materials make almost every cabinet box sold in Ontario. They look identical with the doors closed and they age like three different animals.
The three materials, honestly
Particleboard
Wood chips and glue pressed into a sheet, faced with melamine, a paper-and-resin skin. Cheap, flat, stable, heavy. Holds a screw once. Swells like a sponge where water gets past the skin, and the skin always has an edge. Most stock and much semi-custom cabinetry.
MDF
Wood fibre, finer than chips, pressed denser. Smoother, more uniform, machines beautifully, takes paint like glass. Heavier than particleboard, swells slower but still swells. The best material there is for a painted door. A fair material for a box.
Plywood
Thin wood veneers glued in alternating directions. Lighter, stronger, holds screws for life, and shrugs off a wet sponge left in the sink base. Costs 15 to 25% more per box. Can bow slightly and has visible plies on a cut edge. The box a cabinetmaker builds for his own house.
What happens to each one
When it gets wet
The sink base is the test. A slow drip from a supply line, a dishwasher that seeps at the door seal, a wet sponge left on the cabinet floor. Particleboard takes the water at the unsealed edge, swells to twice its thickness, and crumbles into something like wet cereal. MDF does the same, slower, and swells more evenly, which is almost worse because it looks fine until the shelf sags. Plywood gets wet, dries, and is still plywood. I have pulled thirty-year-old plywood sink bases out of houses that had been through two dishwashers and they were sound.
When it is screwed into
Cabinets are screwed to the wall, to each other, and every hinge and drawer slide is screwed into the box side. Particleboard holds a screw once; take it out and put it back and it holds half as well. MDF is a little better. Plywood holds a screw as many times as you need. The hinge on a particleboard cabinet that has been adjusted five times in ten years is loose, and that is the door that sags.
When it is loaded
A 36-inch shelf of cast iron and canned goods on 5/8-inch particleboard sags visibly in five years. On 3/4-inch plywood it does not. This is a thickness question as much as a material one, which is why the back of the box matters: a 1/8-inch hardboard back stapled on is what keeps a cheap cabinet square, and it does not.
When it is painted
Here MDF wins outright. A painted door needs a surface with no grain to telegraph through, no joints to open, and edges that take paint cleanly. MDF is all of that. Plywood doors show grain and have edges that drink paint. Solid wood doors move with the seasons and show a hairline at every joint by February. The right painted kitchen in Ontario is a plywood box with MDF doors, and most good shops will sell you exactly that without being asked.
What the upgrade costs
On a semi-custom line that offers it, plywood boxes add 15 to 25% to the cabinet price, which on a $15,000 mid-grade kitchen is $2,500 to $3,500. On a custom shop quote, plywood is often the default and the saving for particleboard is small, because the labour is the same either way. Stock lines do not offer it. IKEA’s SEKTION frames are 3/4-inch particleboard with a painted fibreboard back and no plywood option, which is what the 25-year warranty is covering. The calculator prices the grades; ask the shop for the plywood line as a separate number.
If you can only upgrade some of them: the sink base, the dishwasher cabinet, and the cabinet beside the range. Water and heat live there. The uppers that hold wine glasses can be anything.
How to tell what you are buying
- Look at a cut edge. The shop has a sample box or a cabinet with the back off. Plywood shows layers like a stack of paper. MDF is uniform tan and smooth. Particleboard is chips in glue and looks like it.
- Ask the thickness of the sides and the back, separately. 3/4 sides and a 1/2-inch back is good. 5/8 sides and a 1/8 back is builder grade whatever the door costs.
- Ask what the shelves are. Shelves sag first. 3/4 plywood or 3/4 particleboard with a solid wood front edge, not 5/8 with a plastic edge band.
- Lift a drawer out. A dovetailed plywood or solid wood drawer box on undermount runners is the sign of a shop that cares about the inside. A stapled particleboard drawer on side-mount runners is the sign of a shop that cares about the door.
- Get it in writing on the quote. Box material and thickness, by cabinet line. If they will not write it down, you have your answer. The quality checklist has the rest.
Where the trade actually stands
The Kitchen Cabinet Manufacturers Association runs the testing program most North American lines quote, and a KCMA-certified cabinet of any material has passed a set of structural and finish tests that are worth something. Their standards are at kcma.org. Certification tells you the box will not fall apart under normal use. It does not tell you what it does under a dishwasher leak, which is the question that matters in year eight.
For what it is worth: I have installed every kind. Particleboard in a dry, square, well-plumbed kitchen lasts twenty years. The same box in a cottage with a well pump that hammers the supply lines lasts six. Plywood lasts in both. That is the whole argument, and the $3,000 is cheap insurance on a $25,000 kitchen if you intend to be there to collect.
Questions people ask
Is MDF good for kitchen cabinets?
For doors, it is the best painted-door material there is. For boxes it is adequate and better than cheap particleboard, but it still swells when wet. Plywood boxes with MDF doors is the combination most good Ontario shops build.
Are plywood cabinets worth the extra cost?
If you will own the kitchen for more than ten years, yes, and if you cannot do all of them, do the sink base and the dishwasher cabinet. On a rental or a flip, no.
How long do particleboard cabinets last?
Fifteen to twenty-five years in a dry kitchen with no leaks. Five to ten after the first slow leak under the sink. The leak decides, not the calendar.
What is a “furniture board” or “engineered wood” cabinet?
Particleboard. Both are marketing names for the same material. Ask to see a cut edge.
Are IKEA cabinet boxes particleboard?
Yes, 3/4-inch particleboard with melamine faces and a painted fibreboard back. Better than most stock lines on the sides, weaker on the back, and covered by a 25-year warranty that excludes water damage. The IKEA comparison goes through it.
The one line to put on every quote
“Box sides and back, material and thickness.” Five words, and the shop that writes them down without hesitating is the shop whose cabinets you want under your sink.
