Although it is often argued that the resurgence in brickwork design is driven by concerns with cost and sustainability, cultural factors also play a part. In parallel with this his brickwork renaissance, there is widespread innovation in the manufacture of masonry products.
As Wilkinson Eyre’s Siemens Building in London’s Docklands (AJ 27.09.2012) confirms, the notion that glass building envelopes are no longer tenable in these parsimonious emissions-wary times is twaddle. Lightweight construction with extensive glazing is fine for certain briefs and architectural responses. It is true that heavyweight masonry envelopes work well with certain building types and diurnal patterns of use, for example housing, and their inherent longevity suits not only a particular type of brief and real estate framework but also an economy which favours retrofit to scrap and build. But to borrow from Amos Rapoport’s thesis, masonry is often specified for cultural reasons. Perhaps it’s a chicken and egg relationship, but good brickwork construction denotes architectural quality, whereas steel sandwich panels, insulated render and thin rainscreens often struggle to do so. Just look at some of the buildings shortlisted for this year’s Brick Awards. Highlights include The Mac, Belfast, by Hackett Hall McKnight, AHMM’s North London Hospice and Niall McLaughlin’s student accommodation for Somerville College, Oxford, not to mention the work featured in this issue.
‘People are rediscovering masonry, especially brick’, says Ibstock marketing manager Andrew Halstead-Smith.
‘Architectural awards, for example the RIBA regional awards, indicate a resurgence in the number of brick buildings, as people begin to realise that clay is the original sustainable product, especially because of its longevity.’
Traditional buildings, especially in masonry, can be good value when you compare them with others which use imported products.
But Halstead-Smith also argues that manufacturers are now more adventurous and no longer limit themselves to standard sized red and cream bricks. Ibstock’s Fireborn bricks, up to 490mm long and 440mm wide, are available in blacks and greys, with a range of interesting textures. Whereas traditional brickwork textures are dominated by wire-cut and simple creased treatments, Ibstock has developed lined and riven textures.
‘Brick is almost like a fashion material with specifiers going from hand-made effects to others which are crisp and sharp’, says Halstead-Smith. ‘Our Linear range is changing perceptions of brickwork, offering long and thin modules, with heights of 40, 50 and 60mm and lengths of up to 440 or 490mm, which can completely change the appearance of a building.
As Halstead-Smith explains, Ibstock seeks inspiration from many sources.
‘Clay is a wonderful material with such a fantastic heritage: James Campbell and Will Pryce’s Brick: A World History is an excellent source book, which reminds us of the historic achievements of brickwork, for example in the sheer artistry of the extraordinary glazed bricks produced by the Etruscans over 2,000 years ago.’
Clay is a wonderful material with such a fantastic heritage
There has recently been a resurgence of glazed brickwork, for example in Landolt and Brown’s West Hampstead Station, which uses Ibstock Umbra saw-toothed glazed bricks, to produce big and bold effects, using three types of glazed brick with an appearance which changes throughout the day.
‘Most Ibstock bricks are produced in Britain with an average distribution mileage is 62’, says Halstead-Smith. ‘Very few products can claim such localised sourcing. Britain is a natural environment for brick, which is used for 50 per cent of all UK cladding.’
Brickwork exhibits extraordinary regional diversity. Whereas Kent and Sussex Weald bricks are soft and warm, Manchester’s are hard and wire-cut. Although for cultural reasons other external finishes are popular in some regions, for example in the southwest where there is extensive use of render, brick is manufactured throughout Britain.
‘Looking out of the window from Ibsock’s office in Leicester I can see red and cream bricks’, says Halstead-Smith, ‘But I know that just thirty miles away there will be a completely different colour range. Clay is naturally super-abundant and after using it for over 5,000 years we haven’t even scratched the surface of its potential uses. We have 500 hundred brick products in our range and are constantly trying to push the boundaries. We are always excited by the element of surprise, encouraging architects to take advantage of brick’s inherent flexibility.’
Because bricks come in small, compact and regular sizes they encourage architects to pay more attention to detail, for example by experimenting with different bonding patterns.
BrickShield is a new external wall insulation which Ibstock has developed with Rockwool, building on traditional brickwork construction, while enhancing structural performance and helping architects to maximise floor space. ‘This CERAM-tested system enables brick slips to be seamlessly applied to facades and is ideal for the estimated 5.5 to 6 million solid-walled houses in Britain requiring thermal upgrading’, says Halstead-Smith. Ibstock also manufactures the Elementix range of rainscreen cladding systems, including eco-freedom, which uses 90 percent recycled material and was specified by Stride Treglown Architects for its University of the West of England Faculty of Environment and Technology, which demonstrates the flexibility of clay products. There have also been developments in accessories, for example Ancon’s super-low thermal conductivity wall ties, which are overcoming cold bridging concerns.
‘In the past we were unadventurous and failed to capitalise on brickwork’s flexibility’, says Halstead-Smith, ‘But we are now trying to create the unexpected at every stage. The pioneering work on large architecturally-driven projects will filter through to smaller ones over the coming years.’
Another manufacturer, Wienerberger has added more than 30 new bricks to its Terca range over the course of the year, including two new facing bricks: Abbeydale Red Multi, a vibrant red wire-cut style brick with dark hearting and Brookhurst Yellow Multi, a golden yellow stock brick with a warm hearting effect. Both have occasional black surface spotting and are accredited to BES 6001, the responsible sourcing framework which gives housebuilders extra Code for Sustainable Homes points.
Moving on to concrete products, Forticrete has developed a new range of dense concrete masonry blocks which are manufactured with up to 45% recycled content. Part of Forticrete’s ECOBLOCK range, these decorative facing blocks are available in various finishes, profiles and a wide variety of colours. ‘Concrete products are acknowledged in the Green Guide to Specification where they are rated A or A+’, says Forticrete general manager John Lambert. Forticrete has adopted the ISO 14001 environment management system across its sites and has ‘Very Good’ accreditation for the BES 6001 standard for its full product range and all manufacturing sites. Finishes include shot-blasted, with a weathered appearance, Splitface which simulates hewn stone, Burnished Venezia and Polished Florentine, used to create expanses of reflective walls. Available profiles include Standard, Ribloc and Twinbloc. The Ribloc Profile features bold geometric planes which emphasise light and shade, whereas Twinbloc provides inexpensive stack bonding effects.
For work on existing buildings, architects may wish to consider physically inserted DPCs as an alternative to chemical injection. According to DPC manufacturer Dampcoursing, BRE Digest 245 says physical DPCs are the only sure fire method to overcome rising damp. Dampcoursing’sphysical DPCs have a 50 year guarantee and can be used for brick and stone walls up to 1m thick. Bespoke cutting gear is used to cut slots through the walls and if a particularly large stone is encountered, it is removed and then replaced after the DPC is inserted. The thickness of the cutting blade creates a precise opening for the insertion of a physical DPC along with the necessary bedding mortar, which is placed in the slot. The DPC material is taken to site and cut to suit. This process is then repeated, 900 mm at a time. Once the mortar has dried, the wall is re-pointed.