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General instructions for installing engineered hardwood flooring.

Responsibility and Standards

  • Engineered flooring is a natural product. Allow for a grading tolerance of 5%.
  • Acclimatise the flooring for at least two days in the installation environment before fitting.
  • Keep packs sealed until immediately before fitting. If you inspect boards early, reseal the packaging straight away.
  • Some boards may bow slightly due to the lamination process. This corrects itself during installation.
  • Do not install any board with an obvious defect. Contact us before fitting — we can exchange it. Use stain putty or filler stick for minor corrections; this is standard practice.
  • Install to British Standard BS 8201:1987, which covers recommendations for laying hardwood flooring.
  • Once you install the floor, you and the owner accept the product.
  • Do not install engineered flooring in bathrooms. High humidity in those areas will damage it.

Expansion Gaps

  • Leave a minimum gap of 10mm between the boards and all walls. Allow the same gap around fixed objects such as pipes.
  • This gap lets the floor expand and contract with changes in humidity.
  • For rooms longer or wider than 6m, increase the gap by 1.5mm for each extra metre.
  • For rooms longer or wider than 12m, incorporate a movement joint.

Storage and Handling

  • Store packages in a dry place. Open them only immediately before fitting.
  • This protects boards from short-term humidity changes before installation.
  • Never store boards on their side or end.
  • When you remove boards from the packing, do not bend them — this can crack the varnish.

Subfloor Preparation

  • Level a concrete subfloor with a self-levelling compound or screed. Level a wooden subfloor with a sander.
  • If the subfloor is an existing wood floor, check it has adequate support before you start.
  • If the subfloor lacks rigidity, fit 12–18mm plywood — preferably tongue and groove — between the existing floor and the new engineered boards.

Humidity and Moisture

  • Keep the ambient humidity at 40–60% RH and the temperature at 18–24°C during installation and afterwards.
  • Measure the moisture content of the subfloor before laying the boards.
  • For a concrete subfloor, the relative humidity must not exceed 35–40% RH (approximately 2% moisture content). Note: BS 8201 specifies 75% RH, but at that level adhesives will not bond reliably — target 35–40%.
  • For a wooden subfloor, the moisture content must be 8 ± 1%.
  • To test concrete without specialist equipment: tape a 1m² piece of polythene to the floor for four to five days. If condensation appears under the membrane or the concrete darkens, moisture is too high.
  • Always use a moisture barrier on concrete. Over a recently cast slab, lay a 0.2mm plastic membrane with joints overlapping 200mm or taped.

Underlay and Underfloor Heating

  • Always use an underlay designed for floating engineered flooring. We recommend Timbermate Excel or Woodtex with the appropriate joint tape — both incorporate a moisture barrier.
  • If you bond the flooring permanently to the subfloor, use a professional installer.
  • For underfloor heating, use only a flooring product the manufacturer specifies as compatible.
  • You can add a sound insulation layer below the boards. Timbermate Excel or Woodtex work well for this purpose.

Layout and Fitting Details

  • Measure the room width before you start. Calculate the width of the last row. If it would be too narrow, make the first row narrower to achieve a balanced finish.
  • Stagger end joints between adjoining rows by at least 500mm.
  • Apply glue to the top edge of the female groove only — not the bottom. Check the manufacturer’s instructions, as some products vary.
  • Always use a professional tapping block such as a Unika Professional Push Block. Use a pull bar at walls. Never use a board as a tapping block — it damages the top lamina or lacquer.
  • Use professional compression straps to draw boards tightly together for the final fit.
  • Wipe away any glue that squeezes from joints immediately with a damp cloth.
  • If you fit thresholds by screwing through the boards, keep screws at least 10mm from all board edges.
  • Nail skirting boards to the wall only — never to the floor.
  • Lay the flooring last. If other trades continue after fitting, protect the boards with fibreboard or corrugated cardboard.

14–15mm Engineered Floating Floor

You can lay 14mm engineered flooring as a floating floor or bond it permanently to the subfloor. For full bonding, use a high-solids adhesive such as Rewmar MS Polymer flexible wood flooring adhesive. We recommend a professional installer for glued installations.

  • Suitable subfloors include concrete, plywood, existing wooden floors and vinyl floor coverings.
  • Clean the surface thoroughly before installation.
  • The subfloor must be dry and level.
  • Keep humidity at 40–60% RH and temperature at 18–24°C during and after installation.

Step-by-Step: Floating Floor Method

  • Clean the subfloor and check it is level. Use a straight length of board as a guide — allow ±2mm within 2 metres.
  • Level any uneven areas with self-levelling compound (concrete) or a sander (wood).
  • Undercut door linings so the board and underlay slide underneath.
  • On concrete, lay a polythene membrane first, then the underlay. We recommend Timbermate Excel or Woodtex with joint tape.
  • Orient boards to face the main daylight source. Lay them at right angles to any existing floorboards below.
  • Place the first row with the female groove toward the wall. Use 10mm spacers along the wall edge.
  • Fit the last board of the first row with a laying jemmy. Close the header joint, then insert spacers at the narrow end.
  • Apply glue along the end joints and the full length of each lengthwise joint.
  • Apply glue to the top edge of the female groove. Tap boards together with a hammer and professional tapping block. Use compression straps to complete the joint.
  • Start the next row with the offcut from the previous row. Keep end joints at least 500mm from row to row.
  • Fit each board from the open side: close the header joint first, then tap down the length. Use PVA glue on all joints and compression straps to finish.
  • For pipes: drill the hole, cut out the waste with a saw, position the board, glue the offcut back, then cover with a pipe ferrule.
  • Mark and cut the last row using a piece of board as a guide.
  • When the glue has set, remove the spacers. Fix skirting boards or scotia to the wall — do not press them tight against the floor.
  • Leave the glue to cure overnight before use.
  • Re-coat high-traffic or kitchen floors with a fresh coat of lacquer or oil before general use.