Changes to the British Standard for Slating and Tiling BS 5534
In its current guise, the code of practice for slating and tiling, BS 5534:2014, has been mandatory since February 2015. A first amendment was issued later the same year.
February 2018 saw the publication of an updated version with a second amendment. A transitional period for its introduction ends in July 2018. It is likely to become formalised in NHBC technical standards at the beginning of 2019.
BS 5534:2014 + A2:2018 aims to further improve the security, durability and weather-tightness of new and refurbished pitched roofs. It does this in part by referring to a brand new British Standard, BS 8612:2018, which sets out standards for dry fix roofing products and systems, in response to issues of product quality and installation issues.
The full document can be purchased from the BSI website.
What is BS 5534?
As a code of practice, the standard sets out guidance and makes recommendations on best practice for the installation of a roof. Installing to the British Standard 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.
Its 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 or Zurich expect an installation to comply, and the standard is also a foundation for competency schemes like Competent Roofer..
Why was BS 5534 revised in 2014?
The initial overhaul of BS 5534 was driven by extreme weather putting greater strain on roofs and increasing insurance claims, and the need to align with European standards and equivalent Eurocodes.
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; 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.
Why was BS 5534 amended in 2018?
The revised BS 5534 changed the roofing market and significantly increased the use of dry fix roofing systems. The 2018 amendment addresses the challenges that resulted, setting minimum standards for dry fix products and improving the quality of pitched roof installation.
Among the most significant changes are:
● Updating the scope to include “normal re-roofing work, including repairs".
● Clarifying the standard’s scope in relation to heritage roofs, aware 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/or conservation experts is advised, so a suitable approach can be agreed.
● Reference to BS 8216, covering the specification of dry-fixed ridge, hip and verge systems for slating and tiling.
● Support for BS 8000-6:2013, 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.
● Improved interpretation of test results determining the wind uplift resistance of roof tile clips.
More onerous fixing specifications increase installation times, especially where clipping is required. All roofs laid in single lap tiles require some clipping, traditionally using either two-piece aluminium or stainless steel clips and nails.
Marley Eternit’s SoloFix one-piece clip and nail provides an affordable fixing for all standard interlocking tiles. It is up to 30% faster to install than traditional clips, and delivers outstanding strength and durability.
Two videos demonstrating the advantages of SoloFix over traditional clips, including an installation race, are available to watch at marleyeternit.co.uk/solofix.
The widespread adoption of dry fix roofing systems will continue, but is not a new solution. Marley Eternit have produced dry fix products for 30 years and continue to offer an extensive range. Our ridge and hip systems are mortar and maintenance free, and are capable of providing sufficient ventilation to meet the requirements of BS 5250 (code of practice for the control of condensation).
Where mortar bedding is necessary, we offer security ridge and hip kits with enough mechanical fixings to secure up to six metres of each. Clips for small tile cuts at the hip and valley are also available. Installation videos for our mortar bedded security kits are available to watch at marleyeternit.co.uk/securityridge and marleyeternit.co.uk/securityhip.