Slabs for wall cladding are large porcelain panels fixed to interior walls or to the outside of a building. Thin slabs of 3 to 6 mm, with a reinforcing mesh, are used for interior cladding. Facades generally call for thicker slabs and a mechanical or ventilated fixing system designed by the facade engineer.
Never treat a slab as a big tile glued to any wall. Fixing, weight and movement decide whether the cladding is safe.
Which thickness suits which use?
Slab thickness changes weight, strength and the fixing method. Thin slabs are light and suit interior walls, furniture and lining, but they need full support and careful handling. Thicker slabs, commonly 6, 9, 12 or 20 mm, suit exterior work and can be fixed with clips or on rails. Porcelain slab thickness sets out the options and their trade-offs.
Final selection belongs to the project engineer, who must account for wind load, panel size and the building's movement.
How are slabs fixed?
Methods vary by building and local codes:
- Adhesive fixing on a sound, flat interior wall, using a flexible adhesive suited to low-absorption porcelain.
- Ventilated facade systems, where slabs hang from metal rails with concealed or visible clips and an air gap behind.
- Mechanical fixing with undercut anchors in the back of thicker slabs, specified by the system supplier.
- Movement joints at the intervals the system designer sets.
Are porcelain slabs suitable for facades?
Porcelain has very low water absorption, resists frost when tested to the right standard, does not fade in sunlight and does not burn, which are all reasons it is used outdoors. Ask for frost resistance and thermal shock test reports, and confirm colour stability. Whether a product is approved for a facade depends on the system, the building height and the local fire and building codes, so confirm with the facade engineer and authority.
For installation details and handling, see slab installation guidance for customers.
What should you check before buying?
Check flatness and size tolerance, because large panels on a facade show every error. Ask about pattern continuity across slabs, edge quality and the rate of breakage in transit, since slabs are shipped on A-frames and need careful handling; see slab breakage risk in shipping. Request test reports that match the thickness you plan to use, not a different gauge from the same range.
What are the main risks on site?
The main risks are handling, cutting and fixing errors. Large slabs are heavy and fragile on edge, so they need A-frames, suction lifters and trained installers. Cutting thin porcelain without the right tools leads to chipped edges and cracked corners. Poor fixing, for example adhesive that does not fully contact the back of the slab, can lead to debonding. Ask the installer for experience with large-format porcelain, request method statements, and have the first panels checked against the system designer's details before the rest are fixed.
Next step
Facade projects need documented products and a factory that holds tolerance. We find and audit slab manufacturers, check samples and documents, have lots tested and supervise production and loading. Book a free sourcing review with your system details.