62 RCI 0514

RCI May 2014

SPRA MATTERS The truth about product training Training for the so-called ‘Biblical trades’ of bricklaying, carpentry, stonemasonry and the like is firmly rooted in the established generic qualification structure and college-based training. This has evolved over a hundred years for materials that are themselves the bedrock of British Standards for both composition, performance and application codes. As a result, for those embedded in training such disciplines, the idea of manufacturers having a role may seem a little incongruous and perhaps ‘lightweight’ or biased. One of SPRA’s objectives in recent years has been to assuage such prejudice by explaining the role of manufacturer-based training to industry standards. Like many construction materials based on synthetic materials, single ply roofing never got a mention in any religious text, though it covers an increasing number of religious buildings! With the exception of some PVC membrane produced on the flooring line of a major UK manufacturer until the early 1990s, it did not even have a UK production tradition. Even today we have just one UK manufacturer, the remainder coming overwhelmingly from Western Europe and the US. Because it was new, rapidly changing and its application technology was highly proprietary, single ply never suited the slow process of consensus-building which resulted in highly prescriptive ‘recipe’ British Standards such as BS747 for reinforced bitumen membranes, or BS6925 for mastic asphalt. Instead, fitness for purpose was demonstrated by BBA or other UEAtc certification, which met the need for independent testing for product and in-service characteristics, but did not enable comparison between products nor provide detailed instructions as to how to install. Product standards The potential for a generic approach was overtaken by European Standardisation in the ‘90s. Whatever your view on the EU, the ten-year 062 MAY 2014 RCIMAG.COM By Jim Hooker, SPRA technical director process to achieve a suite of pan-European test methods to characterise products – all wrapped into BSEN13956 – was a huge step forward as it removed the parochialism, disguised trade barriers and cost associated with national standards. So now we have an established set of tests but no guidance on how to apply them to a particular design. That is where the expertise of the manufacturer comes in, and it drives the whole ethos of manufacturer responsibility for delivery of quality into the works themselves. Product training To maintain and improve quality, the key pillar of SPRA has always been the supply of membrane product and accessories only to registered contractors that employ installers who have passed a course of specific product training. What does this mean? 1. The installer must be trained in the specific polymer / product range. PVC, Flexible Polyolefin and Thermoplastic Elastomer products do not behave the same. Preparation, welding temperature / speed, evidence of quality and procedures for repair differ markedly. 2. Product-specific training must be recorded on a database and evidence issued as a card showing specific product training, with a maximum five years’ life. 3. Training in one method of attachment (e.g. mechanical fastening) does not imply sufficient knowledge of, say, adhered systems. This must be taken into account in training programmes and records. 4. Primary training must be delivered off-site to a programme and at a facility approved by SPRA. Secondary training via mobile units or field technicians at site is supplementary; it cannot replace bench-work. 5. We know that up to around 50% of single ply is installed by labour-only sub-contractors. The same rules apply to them also. Many SPRA membrane manufacturers publish pocket manuals to help installers in the field. Some also supplement knowledge by using mobile training units. Assessment of skilled workers What about installers who have cards for one polymer / product type and want a card for a similar product? In this case there must be a clear and recorded process of assessment of skills. If these are found wanting, the individual must attend primary off-site training. This is a vital area for site quality control. An individual who has been laying insulation or vapour control layer, or who has worked for years with product X will not have the necessary skills to apply to product Y. This may not show up in the roof field, but it surely will at details. For example, I recently witnessed a failed roof where the installer had applied a welding method used regularly in adhered applications when installing a mechanically fixed system. An unnecessary overhead for employers? Some employers complain about the cost of training but they often overlook the cost of failure. Single ply technology has achieved its popularity not only through flexibility of design and finish, but also because the welded seam is a fused polymer with huge strength if welded correctly. Anyone who doubts should try and break a sound weld by shear or peel stress. Excessive supervision and snagging visits are also expensive, and some employers would do well to consider whether they need the range of manufacturer registrations that they have. What about the roof system Does all this sound very membrane-focussed? You are right; unless the membrane manufacturer is supplying a warranty for the complete roof system (VCL-Insulation-membrane and any finish) they may be reluctant to spend vital training time discussing thermal issues, air permeability or drainage issues. This is where foundation training comes in – much of it applies to all roofing disciplines – hence the opportunity to develop pan-industry training modules. SPRA is working with FRA, LRWA and NFRC on this approach. Got a single ply roofing query or issue you would like to discuss? Contact The SPRA Helpline: Tel: 0115 914 4445 Fax: 0115 974 9827 www.spra.co.uk A SPRA member delivers off-site product training Weld quality is critical-especially at details. No two products are the same


RCI May 2014
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