Floor finishes

Also see:

9.3.6Wood finishes

Wood and wood-based flooring shall provide a suitable wearing surface for the location and intended use. Issues to be taken into account include:

  1. thermal insulation and DPMs
  2. sound insulation
  3. condition of the substrate
  4. directly applied finishes
  5. indirectly applied finishes.

Wood and wood-based flooring should be installed ensuring that:

  • services beneath the floor finish are tested before the floor is installed
  • underfloor heating is kept on, before and during the floor laying
  • wood finishes are conditioned to the appropriate moisture content
  • where required, DPMs are incorporated, in accordance with manufacturer’s recommendations and the design.

Standards relevant to wood floor finishes include:

BS 8201‘Code of practice for installation of flooring of wood and wood-based panels’.
BS 1187‘Specification for wood blocks for floors’.
BS 4050‘Specification for mosaic parquet panels’.
BS 1202‘Specification for nails’.
BS 1297‘Specification for tongued and grooved’.

Thermal insulation and DPMs

Methods of providing insulation include:

  • insulation positioned above in-situ concrete slab (DPM required)
  • insulation positioned above dry, precast system (DPM not required).

Proprietary insulated flooring should be in accordance with:

  • Technical Requirement R3
  • manufacturer’s recommendations on vapour control layers and DPMs.

Sound insulation

Floating floor finishes should be designed and constructed to:

  • isolate the floor finish from the supporting floor and walls
  • avoid excessive movement or squeaking
  • avoid the use of fixings which penetrate the insulation layer
  • ensure there are no airpaths, especially at the perimeter.

Where flooring is to be installed on a resilient material on a separating floor, edges should be isolated from walls and skirtings by a resilient layer.

Where a floor relies on a soft floor covering to provide the minimum standard of sound insulation, the covering should be fixed permanently in position.

Condition of the substrate

Screeds or concrete to receive wood flooring should be dry. The floor should:

  • be tested and the moisture content suitable, in accordance with BS 8201
  • be allowed to cure for a sufficient period of time (generally two months for 50mm screed, and six months for concrete slabs), or
  • have a DPM or vapour control layer incorporated in the floor construction to protect the wood finishes (moisture should not be trapped between the layers).

Screeds or concrete to receive wood flooring should:

  • be free from high spots, nibs and major irregularities
  • have differences in level dubbed out.

Directly applied finishes (wood blocks, parquet, wood mosaic, etc.)

Directly applied finishes should be installed:

  • in accordance with the manufacturer’s recommendations
  • using the correct adhesives, e.g. bitumen rubber emulsion in accordance with BS 8201 or proprietary adhesives assessed in accordance with Technical Requirement R3
  • using evenly spread adhesives
  • according to the specified pattern, and leaving gaps around the perimeter for movement.

Screeds or concrete surfaces should be treated with a suitable primer in accordance with the adhesive manufacturer’s recommendations.

Indirectly applied finishes (softwood boarding, wood-based panel products)

Indirectly applied finishes should be installed with:

  • vapour control layers where required
  • preservative treated battens, in accordance with Chapter 3.3 ‘Timber preservation (natural solid timber)’
  • provision made to support heavy items, such as storage heaters and boilers
  • battens fixed to prevent excessive movement
  • battens spaced in accordance with Table 3.

Table 3: Spacing of battens for indirectly applied floor finishes

Thickness of finish (mm)Maximum batten centres (mm)
Chipboard (type P5)18/19450
Oriented strand board (type OSB3)15450
Other types of floorIn accordance with the manufacturer’s instructions.

Chipboard and oriented strand board should be fixed to battens:

  • with flathead ring shank nails or screws
  • with fixings 2.5 x the thickness of the board
  • at 200mm-300mm centres at perimeters
  • at 400mm centres on intermediate supports.

Plywood should be fixed to battens:

  • with 10 gauge nails or screws
  • a minimum of 10mm from the edges of boards
  • at 150mm centres at perimeters
  • at 300mm centres on intermediate supports.