24 MMA Yearbook 2007 Michael Driver, Director of the Brick Development Association, explains why the traditional material is as much of the present and future as it is of the past. Brick is beautiful We all know that brick is beautiful. Yet we should not let its many aesthetic benefits obscure the growing range of advantages that the material has to offer. The aim of the Brick Development Association (BDA) is to ensure that all of brick’s qualities are promoted not only to construction industry professionals, but also to the general public. Yet it is surprising to see just how many of these benefits are either misunderstood, or simply not known. For example, brickwork is often described as ‘wallpaper’, a term which is as deprecating as it is untrue. In fact, when used as the external leaf of a cavity wall, brick can make significant structural contributions. Consider a typical construction comprising a 2.5mhigh panel with 102.5mm external brickwork and 100mm-thick internal blockwork. Upon analysis, it is found that the external brick leaf improves the slenderness and increases the overall loadbearing capacity of the wall by 50%, compared with a 100mm-thick single leaf wall. Furthermore, 70% of the moment of resistance of the cavity wall is provided by the brickwork. So clearly brick is not just a beautiful façade. Robustness and strength have been associated with clay brickwork for centuries and it is has become a tried and trusted solution where ‘high’ strength is required. The numerous 100-year-old brickwork-arch road bridges still in use in the UK are testimony to this and rather than being demolished to make way for new structures, they are refurbished to rejuvenate their service capabilities. Lasting for centuries It doesn’t usually take much to convince people about the long life of brickwork. So it is very unsatisfactory when BRE groups brick with other materials that are classed as having a life of only 60 years. This not only flies in the face of our collective knowledge, but is also at odds with a BDA-supported study at Leeds Metropolitan University, which has found that in a sample of 860 buildings, the average service period for clay bricks before replacement exceeded 150 years. Brick has proved durable enough to last for centuries, all the while increasing its visual appeal as the years go by. Yet how many materials are there which have a long and useful life during which little maintenance is required and can then be reclaimed and recycled for use on other projects? This demonstrates why it is important to look at the whole life-span and re-use potential when considering sustainability. Life-cycle analysis is one way of looking at sustainability, but there are many others. Since the launch of its sustainability strategy in 2002, the UK clay brick industry has taken significant strides in making brick production more sustainable. This has included both preand post-factory gate improvements that include greater efficiencies in flue-gas scrubbing, recycling waste water and heat back into the production process, the use of energy-efficient kilns and reductions in emissions to comply with government targets. BDA members, who between them account for over 95% of UK and Ireland brickmaking capacity, are actively working with local communities to improve conditions and reduce the impact of brick manufacture. Often, these measures go far beyond what is required, such as where former clay quarries are rehabilitated for local and amenity use. This has so far included the creation of wildlife retreats, but can also include the stabilisation of river banks using willow weave and rammed earth in place of concrete; river re-routing; increasing fish stocks; lorry-wheel washing and more. Material of the future Being perceived as a traditional material can sometimes limit the use of brick. Yet brick is as much a material of the present and of the future as it is of the past. Today’s cutting edge architects such as Allies and Morrison, Caruso St. John, Feilden Clegg Bradley, Sergison Bates and Short & Associates are redefining the use of brick and developing whole new vocabularies. It is thanks to practices such as these that there has been a revival of interest in brick, particularly in brick as an internal finish. And if brick did not offer enough benefits to ensure its continued use, along comes global warming, the corresponding rise in summer solar heat gains and the re-discovery of thermal mass. Recent “Brick has become a tried and trusted solution where ‘high’ strength is required.”

MMA Yearbook 2007 25 research conducted by ARUP has found that high thermal-mass buildings such as those made of masonry have the potential to be significantly cooler than those made of lightweight construction. UK Housing and Climate Change: Heavyweight v Lightweight construction examines the benefits of high-mass construction versus lightweight low-mass alternatives and looks set to influence building design for the next few decades at least. The report cites the potentially poor performance of thermally lightweight construction and how, other things being equal, heavy thermal-mass is able to better absorb excess solar heat gains. Architect Bill Dunster of BDa ZedFactory has warned that as the southern England climate becomes more like that of Marseilles, lightweight homes will become almost uninhabitable without air conditioning or other active cooling. It seems that as in the past, the tables are turning in favour of brickwork and heavyweight construction. Construction developments But despite the popularity of brick, the industry must keep pace with general developments in construction. It has therefore not been slow in devising a steady stream of innovations, all designed to extend brick’s versatility. For example, as a direct response to demands for greater off-site manufacture and reduced build times, the brick industry has created a host of patented time- and labour-saving products. These encompass building systems, cladding products, components and even innovation within the brick unit itself. A typical example is Traditional Plus (TP), an innovative building method that looks set to revolutionise modern housebuilding. The system comprises a single leaf of clay masonry made of special-shaped bricks that provides enhanced stability during construction, greater insulation and proven acoustic performance. The 140mm-wide perforated units can be laid with mortar in the conventional way and are then lined internally with waterproof insulation and the chosen wall finish. Typically, a U-value of 0.26W/m2°K can be achieved. Floor-to-wall connections are made using a special joist hanger that slots into the perforations. Flexible enough for use with the new ‘glue’ mortars, the system meets all regulatory requirements while the reduced wall thickness allows maximisation of internal space. Brick is a durable external cladding which also fulfils loadbearing functions. Pictured, Keyworth Centre, South Bank University, London. Architect: Building Design Partnership. .