Given the nature of our business, this may seem counterproductive, but we are passionate about good brickwork. So, having come across many failed brick matches here are some key points towards achieving the best possible brick match for your new extension, after all, there’s no substitute for getting it right the first time.
Selecting the right materials
There are literally hundreds, if not thousands of brick types in the UK, all with unique colour, texture and technical properties and unless you’ve a record of the manufacturer of your original bricks, finding new bricks to match can seem daunting. Fortunately, there are companies such as Brick Factors and Builders Merchants who have extensive knowledge of the UK brick industry and they will be able to help identify your bricks, provide samples and arrange the supply of the appropriate new bricks for your project
When it comes to selecting your bricks, there are many variables that will affect the success of the match. Brick colour and texture are the obvious ones, but you should also consider the size of your bricks. The current standard brick size is 215 x 102.5 x 65mm. These are known as “Metric Size” bricks. However, prior to going metric, bricks were made to “Imperial Sizes” which could vary according to each brick manufacturer. So, depending on the age of your property, you may have metric or imperial sized bricks. The consequences of not matching the brick size means that you will have to accommodate any difference in size within the thickness of the mortar joint – which will impact on the overall brick match.
The mortar joint represents approximately 17% of the area of a brick wall and has a huge bearing on its appearance. Look at this brickwork diagram. At a quick glance it looks like the geometric shapes are created with different coloured bricks. In fact, all the bricks are IDENTICAL in colour and size, it’s the mortar colour that changes and creates the effect. You’ll need to get your builder to experiment with different sand and cement options to determine what combination gives the closest matching mortar colour.
There are various mortar joint profiles (or finishes) the most common ones include: curved recess (known as “bucket handle”), weather struck, flush and square recessed. Each joint profile creates its own unique shadow effect on the brickwork so it’s important to recreate the same joint profile on the new brickwork.
If you needed any more convincing about the importance of getting the mortar right, look at any row of brick built terraced houses, all with the same bricks, and note the difference in appearance of the brickwork between any house that has been re pointed against one that hasn’t.
Standards of workmanship
Site reference panel
As soon as you take delivery of the bricks, get your builder / bricklayer to construct a site reference panel of about 1m2. It needs to represent every aspect of the new brickwork, including an acceptable quality range for the bricks and their colours, the mortar joint colour and profile and the brickwork bond pattern. It needs to be located somewhere where it can be viewed with the construction project in the background, but not where it might get damaged during the building work. It needs to be protected from the rain, weather and general site splashes. Before laying any bricks, all parties need to accept the site reference panel as the benchmark for quality levels for material and workmanship and refer to it during any disputes.
Although working to the agreed site reference panel should dictate the appearance of the new brickwork, it is recommended that bricks are mixed by taking from at least 3 different pallets concurrently, and where possible the pallets should be from different deliveries. Further mixing can be achieved by taking bricks off the pallets in “vertical slices” as opposed to horizontal layers as that is how the bricks would have been stacked on the pallet at the brick factory. This is particularly useful when the consignment is small and there isn’t many pallets to mix from.
Protection of materials
Pallets of bricks need to be kept dry prior to construction. Left exposed to the rain, the bricks will become saturated which could result in the appearance of efflorescence (white salts) or iron staining (a rusty looking stain) after the brickwork is completed. Typically, pallets of bricks are delivered with a polythene wrapping, but once removed or if none is provided you should provide alternative protection.
It is also important to protect brickwork during the build. Overnight, or when rain is imminent, partially built brickwork should be covered to prevent it from becoming saturated or damaged by frost.