All About Bricks, Blocks and Wall Ties
Bricks, blocks and stone are the main components of masonry construction, whether inside the home or outside it. A wall (a cavity wall, for instance) may contain several of these materials, or just one (as in a brick garden wall). There are several materials to choose from, including eco-friendly options.
Determine how many to buy
When estimating quantities, remember that the measurement of a brick or block does not usually take into account mortar joints, which will influence the eventual dimensions of your wall. However, some suppliers do quote block sizes in nominal figures including mortar joints. For brickwork, an average joint is 3/8 inch; it is sometimes a little larger for blockwork — 1/2 inch. To get a rough idea of how many bricks or blocks to buy, calculate the surface area of your planned structure and divide this by the nominal size of your chosen brick or block.
Many kinds of bricks are available, in terms of composition, color and texture. The main types are shown here. Bricks are also categorized in terms of quality, referring to their resistance to such things as frost attack. This is not instantly apparent in the brick's appearance, so seek advice from your supplier.
Common bricks are clay-based and general-purpose. Today they tend to be used for garden walls, and patching masonry.
Facing bricks have good faces on all sides. Faced bricks have one good face and one or both good ends.
Engineering bricks are very dense and are made of clay. They are used for extra strength and resistance to weather conditions.
Made from lime and sand, these bricks come in a vast range of colors. They are also relatively smooth to the touch, and provide a very uniform finish.
Made from a special form of clay that can withstand particularly high temperatures, these bricks are commonly used in fireplaces.
These bricks are composed of concrete and made in a large range of colors and textures.
Used in a wall's structure to allow ventilation, airbricks are often used around the base of a house, ventilating the area beneath a suspended ground floor.
Bricks are made in different sizes, although 8-1/2" x 4" x 2-5/8" is a common size. There are also other aspects of brick design that vary, such as whether they are solid, cored or indented. These are the three most common brick designs, although many others exist, often designed for specific purposes.
Solid throughout the structure, with flat surfaces on all sides. Both fire bricks and concrete bricks are commonly solid in structure.
Have holes that extend from their upper to their lower faces, and so are not suitable for capping on top of a wall. They are laid in exactly the same way as other bricks.
Faced/indented (Image 3)
Indented bricks have a wedge-shaped indentation (a "frog") in the upper face (some also have this in the bottom face). Bricks can be laid frog up or frog down. Laying them frog up is stronger, but requires more mortar.
Less angular bricks are available for certain tasks such as capping a garden wall, creating a curved wall, turning a corner (as shown) or creating specific sill designs. Most manufacturers and suppliers will have catalogs to display their full range of specialty bricks.
Blocks are a modern development, and are generally larger than bricks. Unless they are faced, blocks are normally covered over for decorative purposes — usually with stucco on an exterior wall, or drywall on an internal wall. Sizes vary, but blocks are often 18 x 9 inches. Depths also vary.
Decorative glass blocks are usually square and may be used inside or outside, often for small features.
Heavy, solid concrete-based block that is used for general construction work.
A lightweight concrete block that is thermally efficient and easy to handle. Used in loadbearing and non-loadbearing walls, depending on specification.
Concrete with cavity
Continuous cavities allow for strengthening rods through retaining walls. Cellular blocks have discontinuous cavities.
Faced Building Block
Concrete blocks are sometimes available with a decorative face and in various colors.
Natural stone varies widely in appearance and properties depending on its origin. Different stones are therefore suitable for different projects. When buying natural stone, quality is important. A load of unfinished stone may produce a lot of waste, while finished stone is more expensive.
Unfinished natural stone generally requires finishing before use. Bear in mind that finished stone needs to have a usable face, as well as the correct dimensions.
Natural stone that has been cut into a block, usually with all faces finished. Cut stone is therefore very expensive and seldom used extensively.
Stone cut to provide smooth sides for neat mortar joints, but with a rough face.
Made from crushed stone, sand and cement, these are molded to mimic natural stone.
To cut a block diagonally from corner to corner, for a gable end, use an angle grinder along a guide line.
Use a stone saw to cut lightweight blocks by hand, following a clearly marked guide line.
Wall ties are used in cavity walls to connect the outer and inner walls, or to connect a new masonry wall to an existing one. Designs vary according to whether a tie is for use with masonry or timber. Some common examples are shown below.
For joining masonry to masonry, or masonry to timber.
For use with timber-frame cavity walls.
Used to secure a block wall to an existing wall. Ties slot into metal profile
DK - Do It Yourself Home Improvement, 2009 Dorling Kindersley Limited
Used to pick up and spread mortar, brick trowels are the largest of the trowel family. They normally measure 10 to 11 inches in length. The two long edges of the trowel can be straight or have a slight curve, known as a Philadelphia pattern.
Lightweight wall tie
Stainless steel with a plastic retaining clip designed to hold insulation sheets in place.