
Expanded metal is a type of
sheet metal which has been cut and stretched to form a regular pattern (often diamond-shaped) of metal
mesh-like material. It is commonly used for fences and grates, and as metallic
lath to support
plaster or
stucco
Stucco or render is a construction material made of aggregates, a binder, and water. Stucco is applied wet and hardens to a very dense solid. It is used as a decorative coating for walls and ceilings, exterior walls, and as a sculptural and a ...
.
Description
Expanded metal is stronger than an equivalent weight of wire mesh such as
chicken wire
Chicken wire, or poultry netting, is a mesh of wire commonly used to fence in fowl, such as chickens, in a run or coop. It is made of thin, flexible, galvanized steel wire with hexagonal gaps. Available in 1 inch (about 2.5 cm) dia ...
, because the material is flattened, allowing the metal to stay in one piece. The other benefit to expanded metal is that the metal is never completely cut and reconnected, allowing the material to retain
its strength.
History
The inventor and patentee of expanded metal is John French Golding, his first British patent was issued in 1884. He forged partnerships with Hartlepool industrialists Mathew Gray, Christopher Furness and Robert Irving Jr., who together with W.B Close brought the manufacture of expanded metal to Hartlepool. The Expanded Metal Company Limited of Hartlepool, United Kingdom, remains a recognised market leader globally in the manufacture of expanded metal to this day and is one of the largest employers locally.
Design

Some commonly used shapes are circles, squares, and diamonds; diamonds are the most popular shapes because of how well the shape absorbs energy and resists mechanical deformation after installation. Other design considerations are the size and angles of the shapes, which will also affect how well the metal absorbs energy and where the energy is spread throughout the expanded metal.
For the diamond shape, there are at least four different angles that come into account, the two acute and two obtuse angles. The larger the angles, the less strength the shape will have because there would be too much space inside the shape. However, if the angles are too small, strength is lost because the shape is too close together, so there is no space for the structure to hold.
The angle in which the shapes are laid also plays a significant role. If the angle is zero the ends of the shape point to the start and the end of the sheet, making straight lines across the sheet of diamonds. This option provide the most strength when it comes to compressing the sheet on its side. This can even take more pressure than a solid piece of metal because the sheet will compress and spread the pressure throughout the s