Wall and ceiling finishes

9.2.5Ceramic wall tiling

Ceramic wall tiling shall provide a surface adequate for its location and intended use (including appearance and durability).

Where a fixed shower or showerhead fixing is provided over a bath, at a height that will permit persons to stand under it:

  • a screen or other suitable means of containing the water should be provided
  • surfaces which will become regularly wetted should be tiled or have an appropriate alternative water-resistant finish.

Backing surfaces for tiling should:

  • be in accordance with Table 9 and BS 8212
  • be strong enough to support the weight of the adhesive and tiling (where separate coats are used, they should be well bonded)
  • provide an adequate mechanical key
  • be sufficiently even to achieve an even and plane tiled surface
  • provide adequate and reasonably consistent suction
  • avoid differential movement; where this may occur, precautions should be taken, e.g. metal lathing or wire netting fixed across junctions
  • be moisture resistant, where frequent wetting occurs
  • be dry, clean and free from laitance, grease, loose material or any substance likely to affect the bond or finish
  • be reasonably even (i.e. not have gaps greater than 3mm for thin bed adhesives or 6mm for thick bed adhesives, when using a 2m straight edge).

Where the backing surface contains soluble salts, and where cement mortar is used as an adhesive, precautions should be taken, such as the use of mortar with sulfate-resisting cement.

Gypsum plasters should not be used where:

  • repeated or persistent heating occurs, e.g. on flues or near heat sources
  • repeated or persistent wetting may occur.

Backgrounds may be improved by:

  • raking out masonry joints
  • hacking and scratching
  • applying a bonding agent (particularly on very smooth and dense surfaces).

Tiles should be appropriate for their location and intended use. When specifying tiles, consideration should be given to:

  • surface finish
  • size and thickness
  • colour
  • edge shape
  • fittings (coves, skirtings, etc.)
  • accessories (soap tray, paper holder, hooks, etc.).

Tiles should be:

  • fixed in accordance with manufacturers’ instructions
  • suitable for the location, intended use and background; their weight on lightweight plaster should not exceed 20kg/m2
  • fixed according to the background, using cement mortar or proprietary adhesive
  • solidly bedded in water-resistant adhesive on a moisture-resistant background, where frequent wetting occurs.

Table 10: Standards for tiling

BS EN 14411‘Ceramic tiles. Definitions, classification, characteristics and marking’.
BS EN 12004‘Adhesives for tiles. Definitions and specifications’.
BS EN 13888‘Grouts for tiles. Definitions and specifications’.

When tiling:

  • courses should be straight and even to form a plane and regular surface, especially around fittings and fixtures
  • there should be no cut or unfinished tiles at exposed edges or external corners
  • joints should be even and cut neatly
  • spacing should be sufficient to allow for expansion
  • up to sanitary fittings and fixings, the sealing method should be in accordance with the design and account for movement
  • proprietary water-resistant grouting should be used in accordance with the manufacturer’s recommendations.

Appropriately designed movement joints should be:

  • built into tiling at centres at a maximum of 4.5m, vertically and horizontally
  • provided at vertical corners in large tiled areas
  • located at junctions where there are variations in surfaces or backgrounds
  • 1-2mm where tiles are without spacer lugs.

Grouting should be:

  • as specified in the design, including mix and colour
  • cement-based epoxy resin or a proprietary product
  • waterproof in and around shower enclosures and where tiling can be saturated.