Roofing battens are a safety critical building material subject to strict grading and quality requirements. Timber Development UK CEO David Hopkins explains why it’s so important to stick to the quality standards when selling, specifying and purchasing these products.
Roofing battens are the strips of wood that you will find secured between the rafters on any roofing structure. Once fitted into place, the battens are then used to secure the roofing felt, as well as any tiles or slates installed as part of the final finish. These battens are intrinsic to the structure of the roof as they help take the loads imposed by any roofing slates or tiles, as well as the pressure applied to the roof by weather events such as snow or strong winds.
Roofing battens (sometimes known as tile battens) are structurally vital to any roof, ensuring the roof is solid, stable and won’t fail once erected. They are also structurally significant during the construction of the building itself; builders and roofers will often walk, sit or lean on these battens while installing tiles, slates and felt – with potentially deadly consequences should the battens fail.
That’s why these products are subject to strict building standards, both to deliver a quality finish to the final roof and, most importantly, to ensure the safety of construction workers while on site.
The Health and Safety Executive has set out clear guidelines for roof work. Document HSG33 recommends that battens are used as secure footholds on pitched roofs – but only if they are graded to the BS5534 standard.
Organisations including the National House Building Council also require properly certified roof battens to be used, with serious financial and legal consequences for any contractor found using substandard, unmarked or incorrectly marked batten products.
Unfortunately, in recent years we have seen a concerning number of poor-quality timber products being sold incorrectly as roofing battens, despite not meeting the British Standard requirements required to be considered such. That’s why it’s so important for everyone, right across the supply chain, to be extra vigilant and double check that the products they sell, specify and purchase offer the expected quality.
Making the grade
‘British Standard 5534:2014+A2:2018 Slating and Tiling for pitched roofs and vertical cladding. Code of practice’ specifies that only battens graded to BS5534 can be called roofing battens, or used as such. The full requirements for correctly graded roofing battens can be found in Annex D of the standard. In particular, the number of large knots, the slope of the grain and the number of growth rings are strictly controlled to make sure the batten is strong enough to cope with the potential loads.
Size also matters here: battens must be a minimum of 38mm x 25mm (or 50mm x 25mm when using slates), and are subject to very strict tolerances (just -0mm/+3mm on the thickness and -3mm/+3mm on the width), to ensure the structure is not compromised.
Recognising an accurately graded, high-quality roofing batten by eye is not easy, especially for those who are new to the trade, or who don’t work with these products every day.
Many manufacturers have added coloured dyes to their preservative treatment process to distinguish them in the market (you may have seen red, gold or blue examples), but these colours on their own are not sufficient proof that a batten is compliant. Every single roofing batten must be indelibly marked showing that it is BS5534 graded, and must also have its size, the supplier’s name, origin and the timber species marked on the batten. TDUK members also use an independent verification process to prove that all roofing battens they sell have been checked by a third-party certification scheme.
Despite this, we’ve seen examples of low-quality battens entering the market that are clearly undersize, or that display the BS5534 stamp despite not being compliant with the standard. Any timber that is not fully BS5534 compliant is simply a piece of sawn, treated timber and is not fit for purpose, so it is vital that battens are visually checked for any obvious signs of non-compliance before sale or purchase. If in any doubt, always ask your supplier for more information and, if they can’t provide proof of compliance, seek another supplier.
All TDUK members who sell roofing/tiling battens and slatings participate in independently audited quality assurance schemes so that you know you are buying a quality, fit-for-purpose product.
Don’t forget the treatment
BS5534 doesn’t specifically say that battens must be treated, but as best practice most battens are supplied with an industrially applied treatment process designed to provide a 60-year design life under Use Class 2.
Tile battens should be treated using an industrial low or high pressure process, rather than a dip treatment, because dip treatments don’t have the process control needed to ensure quality is maintained. Cut ends should also be treated on site with brush-applied preservative, especially if it will be in contact with mortar.
More information about tile battens and the importance of Use Class wood treatments can be found online at www.timberdevelopment.uk
* This article was originally published in the Autumn 2022 issue of Timber Trader magazine.