Everybody knows what size bricks are, don't they? They have always been that size, it's just the right size, and there is no need for anything else.Right? Wrong, or at least not entirely right.
First of all, British bricks are not as they have always been.New developments use metric bricks, in a standard format of 215 x 102.5 x 65mm. Although that is not so very different from 'traditional' imperial bricks, it is enough of a difference for imperial bricks to be required in refurbishment projects.But modular bricks are another story - different bricks for different applications.
In its literature Hanson refers to 'Classic modular bricks', indicating that this idea is not all that new either - it originated in Belgium in 1948.A system of metric modular bricks existed in the UK in the 1970s and 1980s but was never adopted widely.
Now there is a far greater appetite for them, an appetite that Hanson is happy to feed.
Modular brickwork is based around a 100mm module, and consists of one brick plus one joint. For example, the only metric modular brick covered directly by British Standards measures 190 x 90 x 65mm, which gives it a 'co-ordinating' size of 200 x 100 x 75mm. By using modular bricks with lengths of 190 or 290 mm, and co-ordinating lengths of 200 and 300mm, it is much easier to match the dimensions of windows, hence speeding construction and reducing the number of bricks that need to be cut.
Setting out is also simplified.Where brickwork is only one part of a facade treatment, co-ordination of modular bricks with other elements and structures is simpler than for standard bricks.
Another benefit is that modular bricks are slimmer than standard bricks. This means that, for the same total thickness of wall, the wider cavity allows room for more insulation, hence improving the building's thermal performance. With growing demand for improved U-values, and the imminent introduction of Part L of the Building Regulations, this is a distinct advantage.
But performance is not the only reason for specifying modular bricks. Since their height is considerably greater than that of standard bricks, the overall effect is of more brick and less mortar.
This approach is particularly effective with stack-bonded masonry (see feature on Thorpe Park, pages 4-7 of this supplement).
Hanson lists the benefit of modular masonry as:
simple setting-out procedures;
simple design procedures;
standardised dimensions which allow for standard window components;
since modular bricks are 90mm thick this provides a particular advantage over standard 102.5 clay units;
saving on overall wall thickness of approximately 12 per cent;
for a given cavity wall there is the potential to increase the insulation/ air space.
Hanson's modular bricks form part of its Desimpel range, made from high-quality European clays.Their names are chosen to convey appropriate images - either glamorous foreign cities (Cadiz, Cannes, Casablanca) or giants of Europe's artistic heritage (Albinoni, Bellini, Picasso).
Glazed alternative If modular bricks are not sufficiently slick and exotic for you, then the next step has to be glazed brick.Far from the traditional imagery of Victorian pubs and lavatories, today glazed bricks have entirely different cultural associations.
Think of buildings in the Benelux countries and Germany, where the bricks are as crisp and as shiny as any metallic cladding. Think of buildings that enjoy the reassuring human scale of the repeated brick element and a sense of solidity, yet have a sharpness and crispness associated with more recently developed materials. This is the province of the glazed brick: shiny, almost any colour you want, a hard surface that hints at the organic material beneath.
Hanson's Desimpel glazed bricks form the Diamond collection, which it describes as 'a unique range of ceramic glazed bricks and special shapes crafted from pure primary German Westerwald clay to meet the quality demands of our time'.The glaze is a silica base containing feldspar quartz and mineral additives to provide the colour.
The Westerwald clays used to form the bricks are chemically similar.This means that when the bricks are fired at prolonged high temperatures, the feldspar acts as a flux, forming a ceramic bond between the two layers.
The decorative properties of glazed bricks are immediately evident, but durability is also crucial.Hanson's glazed bricks are frost-resistant.Their shiny surface also makes them self-cleaning and maintenance free with, says the company, 'unrivalled anti-graffiti characteristics'.
The range of colours offered is wide enough to satisfy the most innovative of users - varying from pastel blue and rose, through lime green and mint turquoise to white, black, grey, burgundy and, of course, terracotta.Bricks are available with matt or gloss finishes, either fully or partially glazed, and in the full range of British Standard special shapes.The company can also make purpose-designed shapes to order.
If UK architects develop a real enthusiasm for these bricks we could see a brighter and more varied environment.