Conservation meets new build, meets sustainability. This was the theme that emerged from yesterday’s Brick Development Association (BDA) Conservation Day at the Building Centre in London.
Dr Gerard Lynch, the acclaimed expert on historic brickwork and master bricklayer, was first to speak, proving that the art of creating fine brickwork hasn’t vanished despite the loss of some 60,000 bricklayers to the First World War. His theme was gauged work, a technique for creating exceptionally high quality brickwork. It relies on bricks that are ‘rubbed’ flat so that they can be laid with very precise and thin joints; they may also be carved into decorative mouldings. The techniques were superbly demonstrated by Emma Simpson of Simpson Brickwork Conservation.
Although bricks have been a principal part of the UK’s building materials since Roman times, they are as relevant today as they have ever been. Architects are embracing bricks and are using them in innovative ways to add texture and layering to buildings. Meanwhile, brick makers are developing new products such as oversized bricks, prefabricating techniques and mortars.
Mortars cannot be excluded from any debate about bricks – they typically form around 18% of the surface of a wall. Until it was supplanted by cement in the early part of the twentieth century, lime was the material traditionally used. It’s now making a comeback, and not just in conservation work. It’s sustainable credentials coupled with is aesthetic appeal are finding favour with architects, as is its flexibility: it considerably lessens the need for movement joints along the length of a wall.
Ian Pritchett, of Lime Technology, is dedicated to pushing the use of traditional lime based building materials into the new build market as ecological alternatives to cement and petrochemical based products. Indeed he’s now supplying large sites with ready to use lime mortars in bulk silos.
His presentation was compelling. He believes lime mortars are a key to making buildings sustainable. Unlike cement, lime doesn’t glue bricks together so, when a building is demolished, lime mortars, renders and plasters are easily cleaned off the bricks allowing them to be reused. Conversely, bricks that have come into contact with cement are generally crushed and turned into low grade materials such as aggregates, consequently the embodied energy and carbon within them is lost.
Throughout the day, the building that was cited as an example of brick at its best was London’s magnificent St Pancras Station. Extensive repairs and a large amount of new build in brick have been undertaken using lime mortars, along with 50 bricklayers and stonemasons and approximately 1.5 million bricks to complete the project. I recommend anyone with an interested in brick or indeed fine Victorian architecture to pay a visit.
The BDA’s, Brick: Building a sustainable resource for the future can be downloaded here.
Image: St Pancras. Credit: BDA