Porcelain tile
Plain English. Practical detail. UK context.
A porcelain tile is a dense ceramic tile with low water absorption, used on floors, walls and some external surfaces. Porcelain describes the tile body, not a guarantee of slip resistance or suitability for every job. A polished indoor tile and a textured outdoor paver can behave very differently when wet.
Last reviewed: (editorial review against the public sources listed below).
Specify the whole tiling system
The tile, substrate, adhesive, grout, movement joints and any waterproofing must work together. Large tiles need suitable flatness and a fixing method that produces adequate support. Tile weight and background load capacity are particularly important on walls. Check the manufacturer’s declared use and installation instructions rather than deciding solely from thickness or the word premium. In a shower, the background and waterproofing detailing matter even if the tile itself absorbs little water.
Fixing on a real job
The tiler should assess moisture, contamination, movement and the condition of the background before selecting products. A suitable cement-based adhesive is often needed for porcelain because water absorption and tile size affect drying and bonding. Adhesive classification under BS EN 12004 describes characteristics, but a label alone does not design the installation. Notch choice, bedding technique and checks of transferred coverage matter. An adhesive skinning over before the tile is placed can compromise the bond.
Mistakes that cause expensive failures
Dot fixing floor tiles leaves unsupported areas rather than a proper adhesive bed. Tight joints, missing movement joints and poorly planned edges can also create problems. The Tile Association warns against PVA as a tile primer and explains that water-resistant adhesive and grout do not replace waterproof tanking. Do not assume flexible printed on a bag makes any background suitable. A timber wall is not automatically an acceptable tiling background merely because the adhesive claims high strength.
Alternatives and guidance
Ceramic wall tile may suit some lighter wall applications; natural stone offers different appearance and maintenance needs. Neither is a direct swap without checking the system. BS 5385 provides relevant tiling guidance and BS EN 14411 concerns ceramic tiles. Slip performance should be assessed for the expected wet or dry use. Obtain spare tiles from the same batch where practical and keep the product reference. Different batches can vary in appearance and dimensions even when the range name is unchanged.
Frequently asked questions
Is porcelain waterproofing for a shower?
No. The tile face is not a substitute for a properly detailed waterproofing system behind the finish.
Can porcelain be used outside?
Only where the product and installation system are suitable for the external conditions, loading and slip risk.
Should rectified tiles have no grout joint?
No. Accurate edges do not remove the need for appropriate joints and movement provision.
Sources and further reading
Public sources and further reading. Sources checked: 8 November 2026. Consult the original for details and later changes.