Changes to the British Standard for Slating and Tiling BS 5534
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On August 31st, The British Standard for Slating and Tiling (BS 5534) was updated. The widely anticipated and welcomed update contains a number of changes that are designed to improve the overall security of the roof structure.
The updated standard became mandatory at the end of February 2015 with any roof not started by this point required to be installed to the new version. In addition, the grace period for NHBC work finished on July 1 2015. Our guide to the BS 5534:2014 provides a quick overview to the changes and the solutions the roofing industry can use:
What is the British Standard BS 5534?
The British Standard for Slating and Tiling provides the industry with guidance on best practice, relating to the installation of a roof. Contained within it is a vast array of information, ranging from batten selection, to the methods of fixing, through to wind uplift formulas, providing a means of calculating fixing specifications.
Whilst installing to the British Standard isn’t a requirement by law, it can be included within a specification and upheld in a court if necessary. In most instances, manufacturers providing products for the roofing industry will usually ensure their installation guidelines closely follow the standard, and any deviation will require documented evidence to prove suitability. Also, most third party warranty providers, such as the NHBC or Zurich, will only cover a building if it has been installed to relevant British Standards.
Why has BS 5534 been revised?
Although there are a number of reasons for the update, the two main drivers have been:
An increase in extreme weather
There is little doubt that extreme weather events such as gale force winds, driving rain and flooding are on the rise and placing more strain on the UK roofscape than ever before.
Alignment with European standards
As we’ve seen recently with the new Construction Products Regulation, there is a push to harmonise many of the standards and regulations across the European Union. The update to the British Standard for Slating and Tiling will ultimately ensure that the UK is more closely aligned with the equivalent standards and practices outlined in the equivalent Eurocode.
What has changed?
A number of important changes have been implemented, with the purpose of improving the overall security of the roof structure. In summary, the three main areas of change relate to:
An update to wind load calculations means that all single lap tiles have to be mechanically fixed with either a clip or a nail. Whilst the proportion of each will depend on a number of factors, is naturally concern in the industry on how this affects installation time and costs.
The use of mortar as a sole means of fixing roof tiles and fittings is now deemed as insufficient. Not only should careful consideration be given to the creation of a suitable roof mortar through the correct sand and cement mix, but tiles or fittings bedded with this mortar must also be accompanied by a mechanical fix.
With lightweight underlays now commonplace, it has been necessary to issue new guidelines to ensure they are securely installed. In contrast to their traditional bitumen coated predecessors, the new lightweight underlays, if not secured properly, can ‘balloon’ in the roof space, placing a load on the underside of the roof covering, with the potential to dislodge it.
How has Marley Eternit responded to assist the industry?
More stringent fixing specifications will introduce an element of clipping on all roofs laid in single lap tiles. Clipping, in particular, is widely acknowledged as the most time consuming means of mechanical fixing and traditionally involves the use of either two-piece aluminium or stainless steel clips and nails.
In response to these concerns, Marley Eternit has now launched the SoloFix one-piece clip and nail for all standard interlocking tiles, providing an affordable fixing that not only installs up to 30% faster than traditional clips, but delivers outstanding strength and durability.
To demonstrate the advantages of using SoloFix over traditional clips, there are now two informative videos on-line, including an installation race. These can be viewed by visiting marleyeternit.co.uk/solofix
Avoiding mortar with its associated risks and maintenance will always be best practice, and the changes to BS 5534 should assist in the continued adoption of dry fix. Marley Eternit has an extensive range of high performance dry fix solutions, including ridge and hip systems that are not only mortar and maintenance free (BS 5534 compliant), but are able to contribute ventilation to meet the requirements of BS 5250.
Where mortar bedding is necessary, we now offer security ridge and hip kits, providing installers with enough mechanical fixings to secure up to six metres of each. In addition, clips for mechanically fixing small tile cuts at the hip and valley are also available.
Installation videos for both our mortar bedded security kits can be viewed by visiting marleyeternit.co.uk/securityridge or marleyeternit.co.uk/securityhip
What support is in place to assist customers and ensure compliance?
Technical Advisory Service
Fixing specification to the new standard can be requested or you can use our instant online fixing specification tool, TileFix.
BS 5534 Presentation
For industry professionals who wish to understand the changes and ensure future compliance, we are currently offering the opportunity for one of our experienced area managers to visit and deliver an informative presentation on the subject. If you would like to book one of these presentations, please complete the form below and we'll be in touch shortly to confirm a suitable date and time.