Metal mesh is an extremely versatile product and can be used for a variety of different applications. Common uses of metal mesh include balustrade infill panels, facade systems, ceiling tiles and even the ubiquitous radiator grille.
There are many variations of metal meshes available in the architectural market, but ultimately it comes down to three main types; woven, expanded and perforated.
Knowing your mesh
Following profound recent events of the Grenfell Tower tragedy and the COVID-19 pandemic, the built environment is especially concerned with the quality and reliability of products, so it’s important we ensure when we work with manufacturers and suppliers that we understand and trust their product and, in turn, understand ours.
It is always important to consider the material to be used in the application; this may be for reasons such as weight, environment or finish. Expanded meshes are generally made from aluminium because they don’t crack after expanding, whereas stainless steel (certainly for the larger architectural meshes) can tend to crack in the corners of the holes.
Woven meshes, however, tend to be mainly in stainless steel, brass, bronze or copper and not so much aluminium due to this type of mesh lending itself to more natural finishes. However, perforated sheets can be made from pretty much any metal; there is just an obvious cost issue of certain materials, one thing to remember here though is that when punching metals such as stainless steel, it can have a sharp swarf on one side of the panel that can’t be removed.
Woven meshes have an obvious orientation due to their manufacturing process with the warp and weft of the wires. Also, some of the pre-crimped meshes have a front and a back to them owing to the crimping process – this needs considering when the panels are framed.
Perforated sheet has less of an orientation issue, but as mentioned before, it is worth noting that there is a good side and a rawer side. The side where the punch tool goes through is good as it is bevelled inwards; however, where it comes out of the other side, it can drag metal through which can be sharp and can’t be fettled by hand as it will take time. In the case of using stainless steel, this can be an issue, however, aluminium is a softer metal and is often powder coated or anodised so isn’t such a problem.
Expanded metal has four orientations – both sides are different with one side more in relief than the other, and then there is an up/down orientation. Depending on which way the mesh is hung, you can either see up through the panel or, turned upside down, it becomes solid.
Woven meshes have a maximum width dictated by the width of the loom – in the case of standard woven and cable meshes with almost limitless length, which is great if you are doing a long drop that can be tensioned top and bottom. Pre-crimped (rigid) woven mesh will have a maximum width and length so you must make sure you check.
Perforated mesh is limited to the size of blanks that can be obtained from the mill – generally a maximum width of 1.5m and maximum lengths of 3m. For expanded metals, maximum sizes are dictated by the size of the machines and the orientation of the mesh. The standard maximum width (LWM) is 1.5m and length (SWM) 3m; however, some of the larger meshes can be up to 2.5m LWM x 2.5m SWM, this must be checked.
What is your superpowder?
Powder coating is a cost-effective way to apply an almost unlimited range of colours, finishes and textures to metal mesh products.
Powder coating uses an electrostatic charge to attract a fluidised powder evenly across all surfaces of the mesh. The electrostatic charge holds the pigmented powder until it passes through an oven where it melts and adheres permanently to the mesh. After curing, the mesh has a colourful and durable coating that adds to the desired aesthetic of the project.
We have researched several different secondary finish processes that work well with woven, expanded and perforated metals. Different materials are subject to varying local environments, such as plain steel rusting in wet conditions; therefore, appropriate base materials and finishes for interior and exterior applications must be considered.
Powder coatings are a dry powder with no solvents and, therefore, no harmful volatile organic compounds (VOCs). The fumes, upon burning, from powder coatings have very low toxicity and a low rate and density of smoke generation. Thermoplastic (acid-modified polyolefin) powder coatings also have high electrical and thermal resistance, suitable for cable conduits around underground rail tracks. It is not considered detrimental to the fire resistance of the underlying metal.
When working with high-quality powder coating specialist, Powdertech Corby, we work together to ensure the mesh stays true and square during the process, so we only advise using rigid architectural meshes and Banker Wire mesh to be powder coated if they are welded or attached into a framework. Powdertech Corby offers high-performance architectural powder coatings which are popular with the expanded and perforated meshes, creating a tough, durable and beautiful finish. Not only does the coating protect the metal underneath but it also removes any sharp edges that may occur in production.