Is 20mm Oak Flooring Better? Why 20mm Is the New Zealand Standard
Twenty millimetres has been the benchmark for timber flooring in New Zealand for decades. Long before engineered boards existed, solid floors were installed at 18 to 20mm, and builders, architects and installers designed around that height.
Modern engineered construction has not changed the number. It has made it perform better.
What 20mm means
20mm is the total board thickness: a solid European oak wear layer over a multi-layer engineered core. In a high-performance configuration that is roughly 6mm of oak over 14mm of cross-laminated plywood, which is how our boards are built. The core construction is where most of the stability comes from.
The real argument: everything else was designed around it
A floor does not exist in isolation. It has to meet carpet, tile, joinery, thresholds and wet areas, and 20mm is the height at which those junctions resolve without intervention.
Carpet. Underlay alone is a minimum of 12mm before the carpet itself. A 20mm oak floor gives a clean, level transition with minimal height difference, no bulky trim and no ramp.
Aluminium joinery. Most New Zealand door and window joinery is designed around a 20mm finished floor level. At 20mm the flooring runs flush to standard thresholds, inside and out, with no packers or workarounds.
Tile setdowns and wet areas. A 20mm timber floor lets the tiler work down from that height, which creates a natural fall within the tiled area. Better water containment, and less risk of moisture migrating toward the timber. At the junction to a tiled bathroom, ensuite or laundry this is a performance detail, not a finish detail.
Thinner flooring forces adjustments, packers, trims and compromises that should never have been necessary. A build where every junction aligns is not just tidier, it is cheaper to finish.
Refinishing capacity
A 20mm engineered board carries a thick wear layer. Ours is 6mm, which allows four to five full sanding cycles. Refinishing takes a few days. Replacing is a renovation.
Boards in the 12 to 15mm range look similar on the surface and behave differently over time: less stable, limited refinishing, lighter underfoot and a shorter overall life.
How it feels, and how it sounds
The difference underfoot is immediate. Additional thickness reduces flex and produces a solid, grounded feel that thinner boards cannot replicate. It reads as a structural element of the house rather than a surface applied to it.
The added mass also helps with sound transfer between spaces. In multi-storey and apartment work that is a compliance question as well as a comfort one, and the Acoustic Underlay Test Report covers the impact sound result, measured on the 20mm flooring over the 3mm rubber underlay rather than on the board alone.
Underfloor heating
There is a persistent assumption that thinner floors perform better over heating. In practice, performance is governed by stability rather than thickness, and a well-constructed 20mm engineered board is proven across both hydronic and electric systems.
It minimises movement through heating cycles and delivers even, balanced warmth rather than sharp spikes. The operating limits are in the Underfloor Heating Declaration.
Design continuity
20mm is not confined to the floor. Our stair boards are the same 20mm board, so a flight can be wrapped in the material the floor is already made of, with precise mitres, clean edges and seamless transitions. The wall and ceiling boards are a 12mm profile, deliberately lighter for vertical and overhead work, and dimensioned so their joins align with the floor. One palette across every surface, at the thickness each surface actually needs. We cover the thinking behind it in why cohesion is the new luxury.
The short answer
Yes, and not because thicker is inherently better. Because 20mm is the dimension New Zealand construction already assumes, and building to it removes a long list of problems rather than solving them later with trims.
Full specifications, the Installation Instructions and the test documentation are in Resources. To see and handle a full board, order samples or visit the Christchurch, Auckland or Queenstown studio. The range is in Flooring.
