Bricks are such an integral part of the architectural landscape that it’s hard to imagine building without them, but are they sustainable? Not unsurprisingly, the Brick Development Association, which represents the majority of the United Kingdom and Ireland’s clay brick and paver industries, reckons they are and has now published the Industry’s sustainability credentials in a downloadable leaflet entitled; Brick: Building A Sustainable Resource For The Future.
There is no doubt that bricks have staying power. The Romans brought them to Britain, the skills to make them were revived in medieval times and they were the essential building blocks of the Industrial Revolution and our major conurbations. Nowadays housebuilders and architects value them for their ‘kerb appeal’.
According to the BRE publication Sustainable Masonry Construction by Mark Key, the embodied energy contained in around 10 old bricks is equivalent to that contained in a gallon of petrol. This doesn’t sound great from an environmental perspective but it’s worth remembering the potential locked up in a brick. A brick can last a very long time (think Hampton Court Palace and other Tudor structures), provides excellent thermal mass and is often attractive so can contribute to a sense of place.
In the past one of the things that added to the life of bricks was the fact they were bonded with lime mortar. This offered two advantages: it allowed a certain degree of movement within the building, so the bricks didn’t crack, and it allowed a wall to be demolished and the bricks to be reused. Lime mortar works well when holding bricks together in compression but is easily cleaned off a brick’s surface when a wall is deconstructed. Consequently, a brick bonded with lime is easily recycled into a new wall. A brick bonded with cement based mortar doesn’t have the same advantage: try chipping off the mortar and the brick will inevitably be damaged.