Wood flooring adds warmth and character to any NZ home, but choosing between solid wood and engineered wood can be confusing. Both look beautiful, yet they behave quite differently depending on your subfloor, climate, and lifestyle. Here's what you need to know before you buy.
How They're Constructed
Solid wood flooring is exactly what it sounds like — each board is milled from a single piece of timber, typically 18–20 mm thick. Common species used in NZ include rimu, matai, heart kauri (often salvaged), and imported hardwoods like oak and blackbutt.
Engineered wood flooring is a layered product. It has a real hardwood veneer on top (the wear layer), bonded over multiple layers of plywood or high-density fibreboard (HDF) running in alternating directions. This cross-ply construction is the key to its performance.
Stability and Movement
This is where the two products differ most significantly. Timber is a natural material that expands and contracts as humidity and temperature change — a real consideration in NZ's varied climate, from the humid north to the cold, dry south.
- Solid wood moves considerably with seasonal humidity changes. It needs expansion gaps around the perimeter and is generally not recommended over concrete slabs or in areas with high moisture, such as kitchens or bathrooms.
- Engineered wood is far more dimensionally stable thanks to its cross-ply core. It handles humidity fluctuations much better, making it suitable for installation over concrete slabs (including those with in-slab or underfloor hydronic heating), and in open-plan living areas that connect to kitchens.
BRANZ research highlights moisture management as one of the most critical factors in flooring performance in NZ homes — something worth keeping front of mind.
Installation Methods
Solid Wood
- Secret-nailed or screwed to a timber subfloor (not suitable for direct glue-down to concrete without specialist preparation)
- Requires a flat, dry, structurally sound subfloor
- Needs to be acclimatised on-site for several days before installation
Engineered Wood
- Can be glued down, floated, or secret-nailed depending on the product and subfloor
- Compatible with concrete slabs when moisture levels are within the manufacturer's specified limits
- Also requires acclimatisation, though typically less than solid wood
- Many products are compatible with underfloor heating — always check the manufacturer's specifications
Sanding and Refinishing
One advantage solid wood has is longevity through refinishing. Because the boards are thick, they can be sanded back and refinished multiple times over their life — potentially lasting generations.
Engineered wood can also be sanded and refinished, but only as many times as the wear layer thickness allows. A thicker veneer (4 mm or more) gives you more refinishing cycles than a thin 2 mm layer. Always check the wear layer thickness when comparing products.
Appearance
Both products use real timber on the surface, so the look and feel underfoot is genuine wood. Engineered boards are often available in wider planks and longer lengths than solid wood, which can give a more contemporary feel. Solid wood, particularly recycled NZ native timbers, carries a heritage character that's hard to replicate.
Comparison at a Glance
| Feature | Solid Wood | Engineered Wood |
|---|---|---|
| Construction | Single timber piece | Hardwood veneer + plywood/HDF core |
| Stability | Lower (moves with humidity) | Higher (cross-ply core resists movement) |
| Subfloor compatibility | Timber subfloor preferred | Timber or concrete slab |
| Underfloor heating | Generally not recommended | Many products compatible |
| Refinishing | Multiple times | Limited by wear layer thickness |
| Typical thickness | 18–20 mm | 12–20 mm |
| NZ native species available | Yes (inc. recycled rimu, matai) | Limited |
| Relative cost (guide only) | Moderate to high | Moderate to high |
NZ-Specific Considerations
NZ's Building Code (specifically clause E3 relating to internal moisture) means subfloor moisture control is essential. Concrete slabs must be tested for moisture vapour emission before any timber flooring is installed — your installer should carry out this test as standard practice. MBIE Building Performance provides guidance on acceptable moisture levels and building code compliance.
If you're a landlord, note that the Healthy Homes Standards require adequate underfloor insulation in many properties. Flooring upgrades are a good time to address insulation at the same time — visit Tenancy Services for the current requirements.
For sourcing materials, retailers like Bunnings, Mitre 10, and PlaceMakers stock a range of engineered and some solid wood flooring products, while specialist flooring suppliers often carry a wider selection of species and grades.
When to Call a Professional
While a confident DIYer can install a floating engineered floor, most solid wood installations — and any glue-down application — are best left to a qualified flooring installer. Getting the subfloor preparation wrong (incorrect moisture readings, poor levelling, or inadequate adhesive) can lead to costly failures like cupping, gapping, or delamination.
A professional installer will:
- Test subfloor moisture correctly
- Ensure the subfloor is flat to within manufacturer tolerances (typically 3 mm over 1.8 m)
- Select the right adhesive and installation method for your specific product and subfloor
- Advise on appropriate expansion gaps and trims
You can find qualified local flooring installers on tradedirectory.co.nz to get the job done right the first time.