Large Format Tiles

Large format tiles, generally taken as 600 mm and above on the long edge, reduce joint frequency and let a floor or wall read as a continuous plane. They are the default selection for commercial reception, retail and hospitality floors, but they transfer risk onto the substrate and the fixing specification in a way smaller formats do not.

Specifying large format tiles

• Substrate flatness governs everything. A large tile cannot follow an uneven background. Substrates should be flat to SR1, typically no more than 3 mm deviation under a 2 m straightedge, before tiling begins. Correcting the substrate is cheaper than arguing about lippage afterwards.
• Adhesive coverage. Solid bed coverage is required, achieved by back-buttering as well as notching the bed. BS 5385 sets 100% coverage for external and wet areas and effectively requires it for large formats internally, since voids under a large tile cause cracking under point load.
• Offset limit. Keep any brick or offset bond to a maximum of one third of the tile length. Half bonds on long formats produce lippage because of manufacturing bow.
• Movement joints. Perimeter joints at all abutments and intermediate joints at maximum 10 m centres internally, closer over underfloor heating or where the floor is exposed to solar gain.
• Handling and access. Large panels need two people, mechanical suction lifters and a clear route to the workface. Confirm access dimensions before the range is confirmed, not on delivery day.

For formats above 1200 mm see extra large format tiles. For falls and geometrically constrained areas see small format tiles.

Frequently asked questions

What counts as a large format tile?

In general use, 600 mm and above on the longest edge. Manufacturers and installation guidance vary, and the practical threshold is the point at which the tile can no longer be laid without solid bed coverage and a substrate corrected for flatness.

What substrate preparation do large format tiles need?

A sound, dry, flat background within SR1 tolerance, with any deviation corrected by levelling compound rather than by adhesive. On timber, the deck must be rigid and overlaid, and an uncoupling membrane is normally specified to handle deflection.

Do large format tiles crack more easily?

Not inherently, but they are less tolerant of poor installation. Cracking almost always traces to voids in the adhesive bed, an unsound or moving substrate, or missing movement joints, rather than to the tile itself.