The installation method matters almost as much as the product itself. The same hybrid SPC board installed floating over a flat slab and floating over an uneven pre-1980 subfloor will perform very differently. And engineered hardwood secret-nailed to original floorboards produces a qualitatively different result — more solid, more authentic — than the same board floated over a foam underlay. Here's how to think about each method.
Floating installation
The most common installation method for hybrid SPC and engineered hardwood in Australian homes. Boards click together at the edges and float as a unit over the subfloor, without adhesive or mechanical fixing. An underlay (usually IXPE foam or similar) sits between the floor and the subfloor.
Suitable for: Hybrid SPC over concrete slabs, tiles or existing hard floors. Engineered hardwood over concrete slabs. Any situation where the subfloor cannot be fixed to (e.g. over hydronic heating pipes).
Requirements: Subfloor must be flat within 3mm over 1.8 metres. Humps and dips cause stress points in the click system, leading to board separation or squeaking. Perimeter expansion gaps of 10–12mm must be maintained and covered by skirting or scotia.
Limitations: A floating floor has a slight give or hollowness underfoot compared to a glued or nailed floor. Most people don't notice this. Some do, particularly people who have grown up with solid floors. Over large open areas (60m²+) floating floors can also be noisy underfoot without adequate underlay.
Glue-down installation
Boards are adhered directly to the subfloor with a full-spread adhesive. Common for commercial LVT and some residential premium installations.
Suitable for: Areas where floating isn't practical — very large open-plan spaces, radiant-heated slabs where floating might move, commercial applications. Also used for herringbone and chevron patterns where the click system doesn't work.
Limitations: Significantly more expensive to install and extremely difficult to remove or repair. Adhesive residue on the subfloor is a major complication for future flooring changes. Not recommended for most residential applications in Australia unless there is a specific reason floating won't work.
Secret nail installation
A traditional method used for solid timber and engineered hardwood over timber subfloors. A nail gun drives nails through the tongue of each board at an angle, fixing it to the subfloor below. The groove of the next board covers the nail head — hence "secret" nail.
Suitable for: Engineered hardwood (minimum 12mm thick) over timber subfloors. Pre-1980 homes with original floorboards are the ideal application. The timber-to-timber connection creates a solid, quiet floor with zero movement and the authentic feel of a traditional hardwood installation.
Requirements: A structurally sound timber subfloor. Loose boards must be fixed, rot must be identified and addressed, and moisture content of the subfloor must be within acceptable range. An experienced installer will inspect and quote on preparation work before laying begins.
Why it's worth it: The difference in underfoot feel between a secret-nailed engineered floor and the same floor floated is significant. If you have the subfloor for it and you're investing in engineered hardwood, secret nailing produces a markedly better result.
Which method is right for your home?
Our Floor Finder asks about your subfloor type and home age and takes installation method into account when making a recommendation. If you've selected a product and want to verify the quoted installation method is appropriate, our Quote Checker will flag any concerns.