BS 5534 Fixing Specification

BS 5534 is the British Standard code of practice for slating and tiling, including shingles. It covers design aspects such as wind loading, fixing, underlays and battens. The fixing specification is the set of instructions, derived from the standard, that defines how many and which fixings each part of a particular roof needs. Site workmanship is covered by the companion standard BS 8000-6.

Key fixing principles

Following revisions that took effect in 2015, the standard no longer allows mortar to be relied on as the only means of securing a roof covering. Its requirements include the following:

• single-lap tiles must be mechanically fixed, whether or not mortar is also used;
• ridge and hip tiles must also be mechanically fixed;
• tiles at the perimeter of the roof are fixed twice; and
• higher wind loads are assumed than in earlier editions, which generally means more fixings.

How a fixing specification is produced

The standard contains methods to calculate wind uplift on the roof and to compare that load with the tested resistance of tiles, nails and clips. Tile manufacturers typically provide a site-specific fixing specification based on location, building height, roof pitch and exposure, listing the nails, clips and edge fixings for each zone of the roof.

Amendments

• 2014 edition with 2015 changes. Introduced the mechanical fixing requirements and aligned the standard with Eurocodes.
• Amendment A2, February 2018. Improved the interpretation of tile clip uplift tests, set a maximum underlay drape of 15 mm, revised underlay definitions and added guidance on temporary weather protection.

Related standards

BS 8612:2018 specifies dry-fix ridge, hip and verge systems, written in response to products that gave insufficient mechanical restraint. Underlays must be classified for wind uplift resistance using prescribed test methods.

The fixing specification concept is specific to UK practice, but similar wind-based fixing tables appear in other national codes, such as Australian and New Zealand standards and North American tile installation manuals.