For most Australian homes, a 14-15 mm engineered timber plank with a 3 mm real-timber wear layer is the sweet spot — stable enough to lay over a concrete slab, thick enough to be sanded and refinished once down the track, and priced in the middle of the range. Anything thinner is fine over a perfect plywood subfloor in a low-traffic room; anything thicker is generally overkill outside commercial fit-outs. The detail is in matching the plank to your subfloor, your traffic, and what you want the floor to look like in ten years.
Two thicknesses to check, not one
Every engineered timber spec sheet gives you two numbers, and shoppers usually fixate on the wrong one. The overall plank thickness (typically 10-21 mm) tells you how the floor sits, sounds, and behaves over an imperfect subfloor. The wear-layer thickness (typically 0.6-4 mm) tells you how long it’ll last and whether you can ever sand it back. Both matter, but the wear layer is what determines whether you’ve bought a 10-year floor or a 25-year floor.
Overall plank thickness by subfloor
Your subfloor decides the floor of the range you should be looking at:
- Concrete slab (most ground-floor Australian homes). Go 14-21 mm. Thicker planks bridge minor undulation in the slab, sit more solidly underfoot, and reduce the hollow tap that thinner floating floors can have over concrete.
- Plywood or particleboard subfloor (suspended timber). 10-15 mm is fine. The subfloor is already doing most of the structural work, so a thicker plank doesn’t add much.
- Joists with no subfloor sheet. Engineered timber isn’t designed to span joists directly. You’ll need a structural ply subfloor first, then choose the plank thickness based on that.
Whatever the subfloor, it needs to be flat to within roughly 3 mm over a 2 m span before you lay engineered timber. Thicker planks tolerate slightly more variation, but they don’t fix it.
Wear layer is what you’re really buying
The wear layer is the slice of real timber on top — Oak, Spotted Gum, Blackbutt, whatever the species is. Once you wear through it, you’re into the plywood core and the floor has to come up. So the wear layer is the number that decides longevity:
- 0.6-2 mm. Cheaper engineered floors. You can buff and recoat once, but you can’t sand back to bare timber. Fine for bedrooms or rentals; we wouldn’t put it through a busy kitchen.
- 3 mm. The residential sweet spot. Sandable once, sometimes twice depending on the installer. This is what we’d recommend for living areas in a long-term family home.
- 4 mm or higher. Closest you get to solid timber performance. Worth it for high-traffic homes, homes with dogs, or anyone planning to stay in the house long enough to refinish the floor.
Match the plank to the room
Different rooms in the same house can take different specs:
- Hallways and entries. Highest traffic in the house. 14-15 mm plank with a 3 mm wear layer minimum.
- Open-plan living and dining. 14-21 mm. Wider, thicker planks read better in big rooms and feel more solid.
- Bedrooms. 10-14 mm is plenty. See our best flooring for bedrooms guide for the full breakdown.
- Kitchens. Engineered timber works if the kitchen is dry and well ventilated, but if you have a young family or a dishwasher prone to leaking, hybrid is the more forgiving call. Compare options in our best flooring for kitchens guide.
- Bathrooms, laundries, pool surrounds. Don’t lay engineered timber in wet zones. Real timber and standing water don’t mix — see what flooring is waterproof for the alternatives.
A note on underfloor heating and acoustics
If you’re laying over hydronic or electric underfloor heating, thinner planks (10-14 mm) transfer heat more efficiently. Thicker engineered timber can still work, but you’ll want to check the manufacturer’s compatibility statement — some warranties exclude underfloor heating outright.
For acoustic performance — particularly upstairs in apartments or two-storey homes — the underlay matters more than plank thickness. A good acoustic underlay rated to your body-corporate spec will dampen impact sound regardless of whether the plank is 12 mm or 18 mm.
Budget vs longevity
Thicker plank plus thicker wear layer equals more money, both in the product and in the install (heavier planks, more careful subfloor prep). But the long-term cost works the other way: a 14 mm plank with a 3 mm wear layer can be sanded and refinished once instead of being ripped out and replaced. We’ve costed the trade-off in detail in the engineered timber flooring prices guide.
The short answer
For a typical Australian home on a concrete slab, with kids and the usual living-kitchen-hallway traffic: 14-15 mm overall plank with a 3 mm wear layer. For high-traffic homes or anyone planning to stay long term: step up to 4 mm wear layer. For bedrooms or budget renovations on a sound timber subfloor: 10-12 mm with a 2 mm wear layer is honest value. We carry engineered ranges across our Sydney and Brisbane showrooms — bring the spec sheet you’ve been quoted on, and we’ll tell you straight whether the numbers stack up.
Ready to shop? Browse our full engineered timber flooring range online, or drop into our Sydney or Brisbane showroom to see the range in person.