Parquet Flooring Calculator — Block Count & Adhesive

These waste figures are typical installer and supplier guidance rather than a British Standard — increase them for small or irregular rooms. UK timber-flooring suppliers (Chaunceys, Havwoods) advise about 12–15% for parquet such as herringbone and chevron, against roughly 10% for straight-lay planks. This calculator uses 15% for herringbone, 18% for chevron (its angle-cut ends on every block waste more), 12% for basket weave and 10% for straight lay.

Parquet blocks are full stick-down using a flexible flooring adhesive applied to the prepared subfloor with a notched trowel, then the blocks are pressed in. Coverage is roughly 1.0–1.4 kg/m² for solid and engineered parquet using a B11/B12 notched trowel (Mapei, Bostik data) — always follow your adhesive's data sheet. This calculator sizes tubs at 15 kg, the prevailing UK trade pack (Mapei Ultrabond P980/S948, Soudal Parquet, Bona R848); check the pack size of your chosen product, as some are sold in 5 kg, 14 kg or 16 kg units.

Split the room into rectangles and enter each one as its own section using the Add section button; the calculator adds the sections together for you. Block counts are rounded up per section before being added, which covers the extra pattern cuts where the sections join and never under-orders. The pattern waste percentage applies to every section, and adhesive and primer are worked out from the combined floor area because they are spread continuously. Herringbone and chevron generate more junction cuts than straight lay, so consider a higher waste figure for a small or awkward L-shape. Use three sections for a T or U shaped room.

Traditional parquet blocks are typically 230mm × 70mm × 18mm (or 22mm thick). Modern engineered parquet comes in wider sizes up to 90mm wide and longer blocks up to 500mm.

A bonding primer and a damp-proof membrane (DPM) are two different products — don't confuse them. A bonding primer consolidates a sound, dry concrete or screed subfloor and is applied as one coat at roughly 0.10–0.15 L/m² (e.g. Junckers WB Primer ~8 m²/L); plywood subfloors usually need no primer. The primer figure shown here is this single-coat bonding rate. If the subfloor is damp, or residual moisture is above the adhesive's limit, you instead need a liquid surface DPM, applied at roughly 0.25–0.5 L/m² over two perpendicular coats (e.g. SikaBond Rapid DPM ~0.34–0.4 L/m² total; bitumen Black Jack 908 up to ~1.6 L/m²). Always test subfloor moisture (BS 8201:2011 Annex A hygrometer test) and follow the chosen primer or DPM manufacturer's data sheet.

New parquet flooring needs 3 coats of lacquer (or oil finish): one seal coat and two topcoats. Sand lightly between coats with 120 grit. Each coat uses approximately 0.1 L/m².