Patrick Lewis from the Brick Development Association answers readers’ questions about bricks.
A brick loggia blurs the distinction between inside and outside at The Blockmakers Arms, a converted and extended London pub designed by Erbar Mattes Architects.
How do you tackle movement when building with brick?
All buildings move and brickwork is no exception. Clay brick is a natural material and will last forever with little or no maintenance, but only if the installation is correctly carried out. However, it will expand over time. The main factors that contribute to brickwork movement in the UK are the effects of heat and moisture through long exposure to sunlight, and the cycle of being wet and then drying or freezing. Movement issues can be mitigated by various methods, including the use of additional expansion and compression joints, careful consideration of mortar properties and thickness, technical detailing, and design systems.
The loads acting on the structure will also create small amounts of movement – long-term expansion typically equates to one millimetre per one metre of brickwork. Installing correct movement joints that allow for expansion and compression will allow for the internal stresses to be released. Horizontal movement joints for clay bricks at a maximum of 12-metre centres should be about 16mm wide. For concrete bricks, this increases to a maximum of six-metre centres, which can spoil the look of a building and increase the workload and overall cost.
Special façade areas, such as corners, freestanding walls, short returns and parapets, require special attention. Free advice is available here. Always use a qualified structural engineer when designing. Your local brick manufacturer should also be willing to help.
Are bricks sustainable?
Bricks are made of wholly natural materials: clay – which is both plentiful and easily obtainable – and water, and that’s about it! They are inherently durable and use no carbon during their lifespan. Brick buildings are built to last. They will hold back the elements, and even fire, as proven in 1666 with the Great Fire of London. Clay brick currently holds the highest fire rating possible: A1 non-combustible.
While the official line is that brick has a design life of 150 years, history has taught us that many brick buildings last far longer. People have been using clay since Palaeolithic times. The remnants of fired clay brick construction can be dated as far back as 7400 BC and to a specific point in the Middle East, Jericho. In the UK the use of manufactured fired clay bricks dates from the 11th century.
Today’s challenges are to educate and innovate. The BDA’s guide to the use of brickwork in modern methods of construction gives an overview of recent developments in the field.
Suggested embodied carbon figures for brick buildings are in their infancy and may have a skewed representation of just how sustainable clay bricks are. However, with governing bodies improving standards and industry leaders creating ever lower carbon manufacturing and erection techniques, clay brick will remain at the forefront for builders that require longevity and low maintenance.
How do you check the quality and credentials of clay bricks from overseas?
Some imported brick helps to support the industry since the demand for clay brick in the UK is so high. But one must be very careful. Many of us have seen photos of children working in Asian brick factories with black smoke pouring out of chimneys releasing carbon into the atmosphere. No decent business would want to align itself with such shoddy practice. Nothing highlighted this more than the global pandemic and subsequent widespread manufacturing issues.
Clients often ask about the quality and properties of bricks that are not under the jurisdiction of UK and/or EU standards, and although we can attempt to assist with certain matters, this can be a difficult challenge. The BDA has helped people to make up their own minds using the global Brickmakers Quality Charter (BQC), a credentialing scheme that seeks to measure a brickmaker’s ability to work ethically and to quality standards recognised across business norms. If you procure your bricks from a quality brickmaker who adheres to the BQC’s ‘critical assessment points’, then you can be sure that the bricks you are buying meet the basic standards. More information.
How do I check the quality of reclaimed brick?
This is just as tricky as checking the quality of non-UK/EU bricks, but at least you are likely to know the source of the reclaimed brick. Ask the seller where the bricks come from and if they’ve been tested. If they can’t answer, walk away, or at the very least ask for the bricks to be evaluated at a testing house by a qualified engineer. The BDA has produced a guide on reclaimed bricks.
For more information call 020 7323 7036 or email patricklewis@brick.org.uk
