Navigating the New BS5385 Standards: Transforming Outdoor Spaces with Expert Tiling

In May 2024, an update to the British Standard for Wall & Floor Tiling, BS5385, introduced a new Part 3 with significant changes. One key update specifies that when tiling directly onto wood-based surfaces like plywood, you must use an intermediate layer such as an uncoupling membrane, a reinforced tanking system, or a tile backer board.

Another notable change pertains to external tiling. The new standards mandate that movement joints should be included in tile assemblies every 3 to 5 meters. This is due to the increased exposure to thermal and moisture fluctuations in outdoor environments. The Standard further advises that the spacing of these joints might need to be reduced based on factors like sunlight exposure, substrate movement, tile size, colour, and joint width.

For porcelain tiles, the Standard now requires grouting with materials that meet BS EN 13888 standards, specifically recommending a minimum of CG2 or RG type grouts.

Moreover, the Standard highlights the critical role of skilled labour, advocating for "efficient supervision and the employment of trained operatives" whose competency is certified by bodies like The Tile Association.

The trend for tiling external spaces has grown, driven by the desire to enhance outdoor living areas. This is a significant factor in both residential and commercial property markets, particularly in the hospitality sector. External tiling often involves 20mm porcelain tiles or natural stone, allowing for design continuity or contrast between indoor and outdoor spaces.

However, the success of these installations often hinges on the installer's expertise. While DIY enthusiasts and general builders might tackle such projects, they frequently lack the specialized knowledge that professional tilers or landscapers bring.

A landscaper's approach to external tiling differs significantly from that of a tiler. They typically avoid concrete bases, instead opting to prepare the ground by excavating to create a stable, debris-free base, followed by laying a compacted Type 1 (MOT) base and then a permeable bedding mortar to manage moisture.

Conversely, a tiler would prefer a concrete substrate, applying tiles with a flexible adhesive using a 20mm notched trowel, ensuring the bed depth aligns with adhesive specifications. Both methods would involve using a priming slurry for adhesion before grouting.

Maintenance of these installations requires attention to cleaning practices to preserve appearance and slip resistance. External surfaces are prone to quicker soiling, often necessitating high-pressure washing, which should be done cautiously to avoid grout damage. Using an impregnating sealer and a suitable tile cleaner is also recommended for ongoing care.