As interior works move toward completion, the final floor stage must begin with substrate preparation. Suitable substrates include concrete screed, plywood, plank subfloors, or chipboard. Plywood should be at least 12 mm thick and chipboard at least 19 mm thick. The substrate must be flat, stable, and dry before installation begins.
For engineered parquet, the surface is considered suitable when deviations do not exceed 3 mm per square metre. Use a one-metre straightedge or level across the full area to verify this tolerance. Any larger gap must be corrected before installation. Once the substrate is levelled, remove all dust carefully with a vacuum.
The next stage is vapour protection. Use a dedicated vapour barrier membrane or a dense polyethylene film with a minimum thickness of 0.2 mm. In some cases, moisture-resistant coatings are used as an additional protective layer. On top of the vapour barrier, install an acoustic underlay such as foamed polyethylene or compressed cork. For engineered parquet, a 3 mm underlay is commonly used.
Because parquet boards are significantly larger than traditional strip parquet, installation is usually much faster. At the moment of installation, the substrate temperature should be at least +15 °C, and the relative humidity in the room should remain between 40% and 60% during and after the works.
Several installation methods are used. Some systems fix each board to the substrate with adhesive, screws, or nails. Another method connects the boards only to one another without mechanical fixing to the base. This floating installation method is currently the most common. Modern locking systems make installation faster and more stable than older glued tongue-and-groove methods.
Whatever system is chosen, the parquet boards should be acclimatised in the room where they will be installed so the wood can adapt to local temperature and humidity. Boards with a factory-applied lacquer system can usually be installed immediately if the manufacturer permits it.
Expansion gaps are essential. A gap between the wall and the floor allows the wood to move naturally with seasonal humidity changes. In rooms longer than six metres, allow approximately 1.5 mm of movement gap for each metre of floor width. Around heating pipes, drill openings at least 20 mm larger than the pipe diameter.
Boards are usually laid in the direction of the incoming light, which generally means perpendicular to the window. On an existing timber floor, the new boards are typically laid perpendicular to the old boards. Start the first row with the tongue facing the wall and use wedges to maintain a 15 mm perimeter gap. The second row should begin with a cut piece at least 500 mm long, and the transverse joints between neighbouring rows should be staggered by at least 500 mm.
Before inserting each new row, check that the previous groove is perfectly clean. Any dust or debris will prevent a tight joint. Insert the next board at an angle, lower it flat, and press or tap lightly so it seats correctly. The last row is trimmed to width and laid with attention to the same 15 mm expansion gap.
As a final stage, some installers choose to apply an additional protective lacquer layer even when the boards already have a factory finish. This can improve moisture resistance in certain projects. Once the floor is completed, install the skirting boards to finish the perimeter cleanly.
