Build August PDF

Build Magazine 49 Dispelling the Myths of Single Ply im Hooker, the Single Ply Roofing Association’s Technical Director, looks at the recent growth of single ply roofing technology, dispels some of the most common myths surrounding it and examines why the demand for it now is higher than ever before. Single ply roofing membrane has been widely used in the UK and across the globe since the 1970’s, often a common component for large scale industrial projects including airports and sports arenas mostly due to its proven durability, versatility, design and speed of installation. And for this reason, it is now becoming increasingly popular in residential roofing projects including new builds, extensions and refurbishments. Yet despite this growing popularity people still remain wary of it. Why? This article will look at what single ply is, how it can be used in projects of all sizes, and importantly, dispel some of the lingering myths that dissuade some customers used to more traditional materials. What is single ply? Single ply membranes are made from oil and converted into flexible highly durable polymers which are then processed into large sheets and supplied either rolled or folded. Products are up to 2mm in thickness and may also include an internal reinforcement and/or fleece backing and are laid in a single layer. According to a report published by AMA Research1 at the end of 2015 single ply membranes accounted for almost a third of the UK flat roofing market and the same report predicted that longer term, the sector is expected to show higher than average growth. Yet for this level of growth to continue some of the common myths surrounding single ply must be dispelled. Below are five such myths and explanations designed to dispel them once and for all: MYTH 1 – Single ply is only suitable for flat roofs Single ply offers many advantages over more traditional products: because single ply can be attached directly to supporting deck or more likely combined with insulation so it’s suited to any design challenge and roof shape from flat to pitched including curved and spherical. There are three methods of attachment – mechanically fastened, adhered and ballasted – giving the designer a wide freedom of choice in appearance and speed of installation. MYTH 2 – Single ply doesn’t last as long as other types of membrane roofing All Single Ply Roofing Association members’ products are independently certificated for durability in the range 25-40 years. There are working examples in mainland Europe in excess of 40 years; in the UK some of the earliest projects will soon be this old. In comparison, the durability of other types of membrane waterproofing is typically a maximum of twenty-five years. MYTH 3 – Single ply works well for every type of building While single ply is very versatile and works well on most building types and shapes it isn’t the answer to everything and isn’t usually recommended for plant rooms with directly mounted heavy equipment, or balconies that were used as temporary storage during construction. In addition, some single ply membranes aren’t always compatible with other waterproofing solutions unless they’re separated by an approved weatherproof detail so it’s best to get advice from the manufacturer beforehand. MYTH 4 – Single ply has high environmental impact Because of their lightness and single layer application, single ply membranes are highly resource efficient and transport costs are low. Simple attachment processes reduce construction energy. A combination of extended durability and zero maintenance (except for checks of rainwater outlets and so on) minimises in- service energy and resource use. The BRE Green Guide3 offers the highest class rating (A+, indicating least environmental impact) for single ply membrane in the popular warm roof configuration on steel and timber panel decks. Many single ply membranes are also readily reprocessed into secondary products or recycled. J MYTH 5 – It’s difficult to get insurance for single ply roofs. This was true in the past and there was definite reluctance from insurers to recognise the scale, diversity and reliability of single ply. For many online brokers, there is simply no option if a substantial area of the roof is covered in single ply membrane (or other modern technologies). This has now been resolved through SPRA’s collaboration with GGFi2 to develop a new insurance product which offers protection to work carried out using SPRA member products and contractors. In summary single ply technology is a highly resource-efficient, lightweight waterproofing solution whose rapid growth is largely due its versatility, durability and low environmental impact in comparison to other types of membrane waterproofing. Furthermore, it’s easy to install with very little disruption as setting out and attachment are very straightforward and because the materials used are generally lightweight it is generally possible to refurbish on the existing structure. Yet for all this lingering myths and misinformation about usage and performance have probably held it back from achieving its full potential. It’s time the construction industry dispelled these myths once and for all, helping single ply to achieve its full potential as a cornerstone of modern roofing solutions. The Single Ply Roofing Association (SPRA) is the industry’s UK trade association promoting employment and training within the sector and well as providing guidance to all users and specifiers of single ply roofing systems in addition to co-operating with other trade bodies for the purpose of improving the UK roofing industry. 1 - The ‘Roofing Market Report – UK 2015-2019 by AMA Research - 2- GGFi Approved single ply roofing insurance - 3 BRE Green Guide to Specification - Construction