Open a ten year old medicine cabinet and you learn everything about what it was made of. Some interiors still look factory fresh. Others show rust blooms around the shelf pins, swollen board along the bottom edge, or a coating that peels in sheets. A medicine cabinet lives in the hardest spot in a Canadian home: above a sink, beside a shower, cycling between steam and bone dry winter air every day. Here is an honest comparison of the main material families, how each wears in real bathrooms from Vancouver to Halifax, and where each sits on the price ladder.
Why the bathroom punishes materials
Canadian bathrooms swing harder than most. A morning shower pushes humidity near saturation, then forced air heat in the Prairies or baseboards in a Quebec triplex dries the room right back out. That daily cycle stresses joints, seals and coatings, and condensation wicks into raw board edges and sits on cool metal. If your bathroom fan is undersized or rarely used, every weakness below shows up sooner. That does not mean you need the most expensive box, only that the material should match the room.
Anodized aluminum: the long service benchmark
Aluminum sits at the top of the category, and Swiss style cabinets from makers such as Sidler are built this way for a reason. Aluminum cannot rust, it is light enough to make large double and triple door cabinets practical, and it machines precisely, which is why these cabinets tend to have the crispest door alignment and smoothest soft close hardware. Anodizing hardens the surface against moisture without a coating that can peel.
The honest weaknesses: price, first and foremost. This is the premium tier, and you feel it. Second, a deep scratch through an anodized finish cannot be polished out the way solid metal can, though inside a cabinet this rarely matters. For a primary bathroom you plan to keep for fifteen years or more, aluminum is the strongest case for spending up.
Stainless steel: tough, with an asterisk
Stainless steel bodies and trim are strong, hygienic and far more corrosion resistant than plain steel. The asterisk: stainless resists corrosion, it is not immune to it. Harsh chloride cleaners, bleach splashes and hard water left to dry can leave spotting over time, and brushed stainless shows fingerprints. Care is simple, mild soap and a soft cloth, but abrasive pads will scratch the grain permanently. It sits mid to upper tier and suits busy family bathrooms where doors get slammed.
Coated steel: the budget workhorse
Painted or powder coated steel is what most entry level cabinets are made of, and there is nothing wrong with that in the right room. The coating is the whole defence, so the failure mode is predictable: any chip, cut edge or worn spot exposes raw steel, and raw steel plus bathroom humidity equals rust. Shelf supports, hinge screws and the bottom seam usually go first. In a powder room or a well ventilated secondary bathroom, coated steel can serve for many years. Above the sink in a bathroom with a busy shower and a weak fan, expect a shorter life and inspect the interior occasionally so rust never reaches your toiletries.
Wood, plywood and MDF: warmth with homework
Wood framed cabinets match vanities in a way metal never will, which keeps them popular from Victoria heritage homes to Maritime farmhouses. The differences inside this family matter more than the family itself:
- Solid wood moves with humidity. Doors can stick in August and gap slightly in February. A good finish slows this, nothing stops it.
- Plywood is the most stable wood option and handles moisture better than composite board. Worth seeking out.
- MDF and particleboard are flat, paintable and inexpensive, but they depend entirely on edge sealing. Once water finds a raw edge, the board swells and never recovers. The bottom edge nearest the taps is the classic casualty.
Care is straightforward: wipe standing water promptly, run the fan, and watch the finish at edges and around the mirror frame. Wood spans everything from entry level MDF to premium hardwood, so read the spec sheet rather than the photo.
Plastic and ABS: humble but honest
Moulded plastic bodies sit at the bottom of the price ladder with one genuine virtue: they cannot rust or swell. For a rental unit, a basement bathroom or a cabin, that is a real argument. The trade-offs are equally real: plastic flexes, hinges screwed into plastic can strip with heavy use, white bodies can yellow over the years, and the whole cabinet feels light in the hand. Nobody upgrades to plastic, but as a low cost solution in the right room it is a fair choice, not a mistake.
Quick comparison
| Material | Moisture resistance | Typical tier | Watch for |
|---|---|---|---|
| Anodized aluminum | Excellent | Premium | Price; scratches cannot be buffed out |
| Stainless steel | Very good | Mid to premium | Harsh cleaners, fingerprints |
| Coated steel | Good until chipped | Entry to mid | Rust at chips, shelf pins, seams |
| Solid wood / plywood | Good with upkeep | Mid to premium | Seasonal movement, finish wear |
| MDF / particleboard | Fair, edge dependent | Entry to mid | Swelling at unsealed edges |
| Plastic / ABS | Excellent | Entry | Flex, stripped hinges, yellowing |
Choosing for your bathroom, not the showroom
Match the material to three things: ventilation, traffic and how long you plan to stay. A well ventilated ensuite you will own for a decade justifies aluminum or stainless. A powder room with no shower barely tests coated steel or MDF at all. If the cabinet will be recessed, avoid exterior walls in cold climates, insulation matters there, and confirm placement with your contractor and local code before cutting.
Two Canadian notes that apply across every material. If you are considering a cabinet with lighting or a defogger, confirm it carries certification from CSA or an equivalent recognized body, and let a licensed electrician handle the connection to satisfy local requirements. And cabinets ship well across the country, so buyers in smaller centres are not limited to what the local big box carries.
When you are ready to compare real options, browse our full medicine cabinets collection, which spans every tier discussed here. If storage can live elsewhere and the wall deserves glass alone, the bathroom mirrors collection is the natural detour. For more plain spoken buying advice, our bathroom and kitchen guides hub is the place to keep reading.
Frequently asked questions
What is the best medicine cabinet material for a humid bathroom?
Anodized aluminum is the safest long term choice because it cannot rust or swell, with stainless steel close behind. If the budget points to coated steel or MDF, improve the odds with a good bathroom fan, prompt wipe downs, and placement out of the direct steam path.
Is an aluminum medicine cabinet worth the extra cost?
If you plan to stay for many years and the bathroom sees daily showers, usually yes: aluminum keeps its door alignment and interior finish long after cheaper boxes show wear. In a low humidity powder room, or a home you may sell soon, a mid tier material often makes more sense.
Can I put a wood medicine cabinet near a shower?
Yes, with realistic expectations. Choose plywood over particleboard where you can, confirm the edges and back are sealed, run the exhaust fan during and after showers, and wipe off condensation rather than letting it sit. Expect some seasonal movement in solid wood doors, particularly in regions with dry winters.
Do lighted medicine cabinets need special certification in Canada?
Any cabinet with integrated lighting, outlets or a defogger should carry a certification mark from CSA or another body recognized in Canada, with the connection made by a licensed electrician to your local standards. A listing with no certification mark at all is a red flag.
