Brick dimensions, types & bonds
Standard brick dimensions:
For quick reference in a hurry:
UK - 215 mm in length by 102.5 mm width by 65 mm height.
US - 8 in. (203mm) length by 3 58 in. (92mm) width by 2 14 in. (57mm) height
Australia - 230mm length by 110 mm width by 76mm height
For further information and a detailed breakdown on brick dimensions, sizes, types and bonds continue reading:
What is a brick?
Bricks are building materials that are used to form various parts of a building structure. Although they are mainly used to build walls, they can also be used in the construction of other building elements such as foundation, floors and even roofs. See El Cortijo House by Felipe Assadi Arquitectos for example.
A brief history
Bricks have been in use for millennia. The earliest record of bricks being used in building construction is from around 7,000 BC, where the bricks used were hand-molded from mud then dried in the sun.
The industrial revolution marked the mass production of bricks, making it a very popular building material, even replacing the stone.
This happened for two main reasons: bricks had become much cheaper than stone, and stone had already gained a reputation for being a notoriously difficult and unpredictable material to work with.
Over time, bricks have remained popular in the construction industry. Their constant use has paved the way for more sophisticated building features such as columns, fireplaces, arches, chimneys, among other structural designs.
This is largely due to their ease of use and the fact that they allow the designer to be more flexible and creative in designing uses for them. Bricks are also extremely strong, durable and have cheap maintenance costs. They can also be easily manipulated into interesting and complex structures.
In the recent past, with increased innovations in building technologies, other building material solutions have been developed, most of which make arguably better building alternatives.
It has often been argued that compared to these new alternatives, bricks have become time-consuming, structurally limiting, expensive and take up too much storage space and labour on-site.
However, bricks have also kept up with changing times. If you do not want to use a traditional brick, you could always opt for pre-fabricated brick panels, or newer slimmer profiled bricks, such as Petersen Bricks Kolumba brick.
What are bricks made of?
Today, bricks are made from a number of materials like clay, concrete and calcium silicate. Of these, clay is the oldest material, having being used as the primary component in brick making for thousands of years.
How are bricks made?
There are several ways through which bricks can be manufactured.
There are the soft mud and dry press brick manufacture processes, which both start with curing the clay that will be used in the process.
As the name soft mud suggests, the bricks are made out of a thin mix of mud. On the other hand, dry press bricks use a thicker mud mix that results in a crisper definition. The greater the force applied in pressing the brick in the mold, the stronger the brick becomes.
Firing the bricks for a long time also makes them stronger.
There are also extruded bricks which are made through pushing the brick mixture through a die. This creates an extrusion, which is cut with a wire producing bricks according to the desired length.
Bricks can also either be compact solid or be perforated to reduce the amount of filler material used.
They could also have indentations on their surfaces (either on one side or both), this feature is called a frog.
The frog is filled with mortar during construction when they are laid.
The manufacturing techniques could also be used to categorize bricks. Here we have two categories of bricks: machine-made bricks and handmade bricks.
Machine made bricks:
If you want a cleaner and smoother finish on your bricks, this is the best option. These bricks have more uniform shapes and are also cheaper compared to their handmade counterparts.
These bricks are more expensive because they have a rougher texture, an attractive creased face, and they also account for the physical effort put in while processing the brick. The bricks could also come in a range of sizes and colors.
The following are some of the special bricks that are made for particular circumstances.
1. Radial, arch or tapered bricks.
2. Angle bricks which form returns and chamfers
3. Capping and copping bricks
4. Plinth bricks 5. Sill bricks
6. Bullnose bricks
7. Soldier bricks- they form returns to soldier courses
8. Brick slips used for cladding
There are also Engineering Bricks, which have high strength, good acid resistance, and low water absorption. These are used in civil engineering applications.
Bricks can be cut to size to suit the function they are being applied for in the project.
Bricks can be molded into different sizes and shapes according to set standards, preference or applications. Different countries follow different standard brick sizes and measurements/dimensions.
Large bricks are difficult to burn and are heavy, making them cumbersome during use. When using large bricks in construction projects, masons find it hard to handle them with one hand. A lot of strength is therefore used up in heavy lifting at the expense of speedy work.
Conversely, if the bricks are too small, a lot of mortar is required, which is uneconomical. Usually, the standard dimension is set for various brickworks. The actual/specific size is the real measurement of an individual brick.
The normal size includes the actual size and the width of the mortar at the joint between consecutive bricks. This standardization serves to strike a balance between speed and economy through the individual brick size.
Most bricks are also made in such a way that the real sizes fit in a 4-inch grid. This obeys the modules of other materials and fittings like doors, windows, wardrobes among others.
UK standard brick dimensions / size
There are a variety of brick sizes in the UK in accordance with the standards in use. The brick sizes have remained constant for quite a while.
The standard brick dimension in the UK is
215 mm in length, 102.5 mm width and 65 mm height.
The overall ratio for a standard brick is therefore 3:2:1.
Looking at the construction of a stretcher bond, the standard dimensions considering a standard mortar joint of 10mm, the stretcher bond's dimensions will be 225 mm long and 75 mm high.
If the bricks are laid across each other, two widths (of 102.5 mm), and two mortar joints result to the same repeating unit which is same to the standard length of a brick, ie, 120 mm.
When the bricks are laid lengthways, 3 65 mm heights' and 3 mortar joints result to the same repeating unit like the length of a single brick, ie 120 mm.
United States standard brick dimensions / size
The American Society for Testing and Materials (ASTM) is liable for controlling the standard of modern bricks in the United States. The body has come up with the following standard sizes for bricks:
1. 8 in. (203 mm) length x 3 58 in. (92 mm) width x 2 14 in. (57 mm) height which is the standard size set for a normal brick.
2. the most common modular brick they use is 7 58 in. (194 mm) length x 3 58 in. (92 mm) width x 2 14 in. (57 mm) height.
3. The modular brick is used with a 3/8 in mortar is used to calculate the number of bricks in a given run because it is easy.
Australia standard brick dimensions / size
The standard brick size or the working size in Australia is 9.05 in. (230mm) length by 4.33 in. (110 mm) width by 3.00 in. (76mm) height as per the Australian Standard AS4455. However, some bricks have work sizes like;
1. 11.42 in. (290 mm) length by 3.54 in. (90 mm) width and 3.54 in. (90 mm) height (one square face)
2. 11.42 in. (290 mm) length by 3.54 in. (90 mm) width and (50mm) height
The above bricks are used in construction to bring certain aesthetic effects. Larger bricks promote more economical laying, and they can also be combined with smaller bricks for design purposes.
Other key brick dimensions
In areas that are prone to cyclones, larger bricks measuring 11.42 in. (290 mm) length by 5.51 in (140 mm) width and 3.54 in. (90 mm) height can also be used.
Hollow bricks are used because of the reinforcement done by grouting.
Wider 5.51 in. (140 mm) bricks could also be used for walls that need a lower sound transmission, high load-bearing capacity and high fire resistance.
Generally, the specific properties needed on a wall will influence the work sizes of bricks used.
In the UK, bricks are graded under British Standards. These standards ensure the bricks meet the necessary criteria such as water absorption, strength, frost protection among others.
All bricks are made in accordance with standards like EN771-1 which advocates that all external works should be classified as extremely exposed to the risk of frost attack. For this reason, all designs and builds should be done accordingly.
Clay bricks are prone to freeze-thaw. You are advised to choose a brick of minimum rating F'. F1 is for bricks prone to moderate exposure to elements, a good example are bricks under the eaves. F2 is the highest, it represents bricks that are resistant under severe exposure to saturation and freezing.
Mortars should also conform to the requirements as of BS EN 998-2, for factory-made mortar, if they are site batched, refer to BS1996-1-1, Eurocode 6. These standards define properties like strength.
There are many ways to lay bricks. They can be laid as soldiers (upright), stretchers (lengthwise), and headers (width-wise along the wall). The mortar used in the joints bonds the bricks together. The profiles can be manipulated depending on the exposure or specific visual effect.
The most common profiles are bucket handle, weather struck, recessed, weather struck and cut, and flush (rag joint).
There are many standard bond patterns, including;
1. English bond, which has alternating courses of headers and stretchers.
2. Stretcher bond has each stretcher offset by half a brick. The half brick is relative to the course above and below. This style is common in the UK.
3. American common bond. It is similar to English bond but has only one course of headers in every 6 stretcher courses.
4. English cross bond. It has alternating courses of headers and stretchers. The alternating stretcher course is offset by half a brick.
5. Flemish bond with alternating headers and stretchers in every course.
6. Sussex bond-it has three stretchers and one course of headers.
7. Garden wall box- it has one course of headers against three courses of stretchers.
8. Header bond- headers are offset by half a brick.
9. Stack bond- bricks are laid directly on top of each other, with aligned joints. These bonds are weak. Reinforcement is fundamental in such an arrangement.
Designing with brick dimensions
Many manufacturers produce bricks according to their own specifications. It is important that you look at their specification tables so that you confirm sizes before you make a purchase.
Understanding brick dimensions and sizes
It is important to understand different brick sizes to avoid any confusion. There are three different dimensions:
Specified brick dimensions:
These are the brick dimensions that architects use when they design walls. They are the anticipated manufacturer's dimensions of a single brick without considering the mortar joint size. It is often included in the architect's drawings and specifications. Specified brick dimensions are the only dimensions used in non-modular construction.
Actual brick dimensions:
These are the final brick measurements as they come out of manufacturing. They are always within certain tolerances of the specified size as spelt out in Standard Specification for Facing Brick, ASTM C216 and ASTM C652, Standard Specification for Hollow Brick. These tolerances vary with the size and type of brick. They do not affect the overall design because they are minimal.
Nominal brick dimensions:
These are mainly used for modular construction. Nominal brick dimensions include the specified size plus the size of the mortar. Bricks are made in a way that the nominal sizes fit into a 4'' grid, this way, they coincide with other building materials and fittings such as windows, doors and other wood components like wardrobes.
Architects' Brick Selection
It is important for architects to understand brick dimensions and sizes because it helps them in detailing walls. Many architects tend to only select bricks based on colour and bond pattern. It is important to understand that the brick size is directly linked to the bond pattern and manufacturer's specifics.
The mortar's size does not usually affect the wall's aesthetics. However, it is important when it comes to detailing. The size of the mortar will be affected by the size of the brick selected, which will directly affect the number of bricks that can be used and how they can be laid.
Mortar Joint Sizes
The most common mortar joint used in construction is 0.38 in. (9.53 mm). According to International Building Codes TMS 602, on the Specifications for Masonry Structures, the default size for mortar joints is 0.38 in. (9.53 mm). Always use your brick's specified size when referring to this.
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