Changes to the British Standard for Slating and Tiling BS 5534 

As a code of practice, BS 5534 sets out guidance and makes recommendations for the installation of slates and tiles, and all aspects of pitched roofing above the rafters. It applies to new-build pitched roofs and vertical cladding and has undergone several updates since its publication.

What is BS 5534?

BS 5534 is the code of practice for installing slates and tiles to new-build pitched roofs and vertical cladding. It was the first guidance of its kind to provide recommendations on the design, performance and installation of new-build pitched roofs using slates, tiles, shingles and shakes. It also covers normal re-roofing work and repairs.

Installing to BS 5534 isn’t required by law, but its inclusion in a specification can be upheld in court if necessary and following its guidance aids compliance with building regulations.

The British Standard’s contents include batten selection, methods of fixing, wind uplift formulas and a means of calculating fixing specifications. Product manufacturers in the roofing industry typically make sure their installation guides are aligned with BS 5534, with any deviation requiring documented evidence to prove suitability.

Third-party warranty providers like the NHBC and Zurich expect installations to comply, and the standard is also a foundation for competency schemes like Competent Roofer.

What changes have been made to BS 5534 - and when?

In recent years, updates to BS 5534 have aimed to raise the standards in roofing. In 2015, changes were driven by extreme weather, which was putting more strain on roofs and increasing insurance claims. There was also a need to align with European Standards and equivalent Eurocodes.

The 2015 amendments made it clear that mortar could no longer be relied upon as the only means of securing the roof covering. Single-lap roof tiles and hip and ridge tiles all had to be mechanically fixed regardless of the use of mortar, while tiles to the perimeter of a roof had to be fixed twice. Higher wind loads were assumed, requiring more fixings generally and improved guidelines on the installation of underlays.

These changes led to the widespread adoption of dry-fix pitched roof systems. Roof tile manufacturers looked to capitalise on the shift away from traditional mortar bedding to mechanical fixing, while contractors enjoyed the promise of faster and easier installation. 

However, two main issues occurred because of the rapid expansion of the dry-fix market:

• An increased range of products became available - they were of variable quality, and there was no defined way to compare them.
• Site work problems, such as confusion over the installation of breathable membranes and underlays over rafters and the appropriate drape.

These issues led to problems with finished roofs. The most common included verge systems not providing sufficient mechanical restraint and failing to shed water from the roof verge without staining the gable wall.

To combat these problems, the standard was again updated in February 2018, and a second amendment was added. This new set of changes was intended to:

• Combat the poor installation quality of dry-fix pitched roof products that had become more prevalent
• Increase confidence that building owners were being provided with durable, weathertight roofs, both new and refurbished.
• Expand on previous revisions and clarify points of uncertainty.

The amendment, BS 5534:2014 + A2:2018, aimed to further improve the security, durability and weather-tightness of new and refurbished pitched roofs. It does this, in part, by referring to BS 8612:2018, which supports BS 5543 by setting out fixing and roof ventilation standards for dry-fix ridge, hip and verge systems for slating and tiling. 

Other significant changes included:

• Updating the scope to include normal re-roofing work, including repairs.
• Clarifying the standard’s scope in relation to heritage roofs, noting that its recommendations may not be appropriate. Fixing methods for traditional roofing materials often conflict with BS 5534, and consultation with local planning authorities and conservation experts is advised so that a suitable approach can be agreed.
• Support for BS 8000-6:2013 (now BS 8000-0:2014), covering workmanship of slating and tiling on site.
• Further guidance on roof underlays, including the classification of their wind uplift resistance by prescribed test methods; changes to the definitions of low water resistance (LR) and air-permeable underlays; and a maximum drape of 15mm. There is also a revised clause about temporary weather protection, before the installation of the primary roof covering, aimed at protecting them from exposure to UV light.
• Improved interpretation of test results determining the wind uplift resistance of roof tile clips.
• New definitions relating to the continuity of ceilings.

The full document can be purchased from the BSI website.

Compliance with BS 5534

The widespread adoption of dry fix roofing systems will continue, but it is not a new solution. Marley has produced dry-fix products for 30 years, and our range of trusted roofing products is designed to meet the requirements of BS 5534. Our solutions are also backed by a full 15-year system guarantee.

For example, our SoloFix one-piece clip and nail provides easy and affordable dry-fixing for all standard interlocking tiles. It is up to 30% faster to install than traditional clips and delivers outstanding strength and durability. 

If you’d like more information or help to ensure a project meets the requirements of BS 5534, contact our technical team on 01283 722588, or find your local Marley specialist.