Building blocks

If you are planning a building project, one of the first steps is choosing the right bricks or blocks for the job.

 

Gina Hartoog

 

A brick is just a brick, right? Wrong! In this feature we look at the classification of clay and cement bricks and well as other building blocks that can be used in various applications in the home.

Bricks are rectangular blocks used for building and they have been around for centuries. The most common bricks we know today are clay and cement bricks. Bricks and blocks are generally laid in mortar to build walls or other fixed structures inside and outside the home. In South Africa, the brick braai is a popular DIY project for the garden.

 

Bricks are a durable choice of building material as they are able to withstand severe weather conditions and high winds. Cement blocks are often used to construct retainer walls in the garden.

 

Colour, texture and size

Cement stock bricks are grey in colour. They are suitable for building work which is going to be plastered. Clay face bricks are available in myriad different colours to suit every taste and application.

 

In most cases the colour of the brick is determined by the raw materials used and their mineral content, as well any additives. Colour can also be changed during the manufacturing process - a long firing time results in a darker coloured brick.

 

Face bricks also have different textures which add to the completed project’s aesthetic appeal. A plain-coloured brick can look very different with the addition of a texture to the brick face.

 

Three common textures for face bricks are satin, travertine and rock face. Satin bricks have a smooth finish, while travertine is more textured. Rock face bricks have a rough, stone-like face. Corobrik also includes a coral and rustic texture in their range.

 

Cement and clay pavers are used to pave driveways, paths, patios and areas around the swimming pool.

 

Brick strength is measured in megapascals (MPa). SABS approved masonry units are 7 MPa – 14 MPa bricks sold with a valid SABS Certificate, while SABS specification masonry units are sold as 7 MPa, without valid certification. Brick strength also depends on how long bricks are given to mature after production. They longer they mature, the stronger they are.

 

Types of bricks

Face brick extra (FBX)

These are clay face bricks selected or produced for their durability and highest degree of uniformity of size, shape and colour. FBX is the golden standard of bricks. They can be used for both exterior and interior building projects where a high degree of perfection is required.

 

Face brick standard (FBS)
FBS bricks are durable clay face bricks that are uniform in size and shape. They can be used for all general masonry projects. Tolerances are not as strict as with FBX bricks but the brick is still of a high quality.

 

Face brick aesthetic (FBA)
These clay face bricks are selected or produced for their durability and aesthetic effect, which is derived from non-uniformity of size, shape or colour of the brick. Wider tolerances are allowed on FBA bricks (also called semi-face bricks). They are a popular choose where a rough or more rustic look is required.

 

Non-facing plastered (NFP)
NFP clay bricks are suitable for general building work that will be plastered. These bricks are also known as stock or plaster bricks. Non-facing extras (NFX) are clay bricks suitable for use, plastered or unplastered, in general building work where durability rather than aesthetics is the key selection criteria, for example, below a damp-proof course or under damp conditions or below ground level.

 

Clay pavers (PA)

Clay PA pavers are paving bricks selected or produced for their durability and for a high degree of uniformity in size and shape, and that have dimensions such that the ratio of work size length to work size width is approximately 1:1, 2:1 or 3:1. Most PA pavers have a bevelled edge.

 

Clay pavers (PB)
Clay PB pavers are selected or produced for their durability and for their uniformity in size and shape.

 

Special-shaped bricks

These are any bricks that are not rectangular in shape. They may be single or double bullnose bricks, angle and cant bricks, arch bricks, capping, plinth bricks and spiral bricks. They are available in the same colours and textures as the range of FBX, FBS and FBA bricks.

 

Cement stock brick

Commonly called a ‘mampara brick’ in South African building lingo, the cement stock brick is often selected as a cheaper building option for walls that will be plastered. Cement stocks are manufactured to the standard brick size, but most manufacturers also offer a maxi size option. Bricks at 7 MPa are suitable for a single storey building or boundary walls, and 10 MPa bricks for both single and double storey.

 

Cement blocks

Cement blocks can be used to construct exterior walls, boundary walls and, when used with re-enforcing, can be used for load-bearing walls. The holes in concrete blocks are called cores. They aid in insulation and lower the weight of the block. Steel bars can also be inserted into the cores for added strength during construction. A variety of colours, sizes, shapes and textures are now available, including interlocking concrete blocks. Compressive strength for blocks varies between 3.5 MPa and 7 MPa.

 

Cement pavers and interlocking pavers

These come in a range of different colours and textures. They are durable and able to withstand severe weather. Interlocking pavers can be used on driveways or for commercial applications where there is heavy traffic.

 

Glass bricks

Glass bricks can be used to construct sections of interior and exterior walls and allow light to enter the home without compromising on privacy. They are a popular choice in bathrooms, on stairwells and in other focal areas in the home. Glass bricks provide a solution for an area with an unsightly view while still allowing light inside the home. They also have a higher insulating factor than regular window glass. They are easy to clean and come in a wide range of colours, styles and designs.

 

Decorative retainer blocks  

Retainer blocks are used to build retaining walls, level a steep slope or enclose a section of the garden. Retaining walls are becoming more popular in landscaping and are no longer designed to blend into the background. Decorative retainer blocks can be used to create a retaining wall that is both eye-catching and functional. They are available in various colours to suit your home’s style and colouring.