In a nutshell
- Expanded mesh is a practical, cost-effective and potentially visually appealing option for architectural façades
- Metal is cut and stretched to create expanded mesh in a relatively simple process (with minimal waste) compared to bespoke perforated metal panels
- Expanded mesh has inherent strength and can be installed in larger sheets than perforated panels
- Sheets can be coated in a range of colours and finishes, or turned upside down to achieve design impact
- Expanded mesh is a good option when larger areas of ‘free area’ are required – say for ventilation in a car park
Because it’s formed from a single piece of metal, there’s no waste. The fabrication process and the thickness of the metal give the mesh inherent strength, while the panels keeps their shape when cut. For example, sheet sizes can be up to 1,500mm without the need for stiffeners. Perforated panels? Around 800mm.
What are perforated panels?
Perforated panels are made from flat sheets of metal with holes or designs punched out or laser-cut.
Unlike expanded mesh, panels are typically bespoke, with customised designs on individual panels (or even across entire façades). As a result, manufacture can be complex – making it more expensive than expanded mesh. It’s considered a more premium product, though.
What are the design possibilities of expanded mesh?
Colour for a start. These days, you’ll see expanded mesh panels powder-coated or anodised in a range of colours. While not bespoke, panels also come in an increasingly varied range of patterns, created by the shape and size of the ‘eyelet’.
But here’s another suggestion. The fabrication process creates an obvious top and bottom to each panel – so installing them ‘upside down’ can create a completely different look. Shadows will be different and you’ll see more or less metal depending on the orientation.
Read more about colour and coating options
Sounds too good to be true. What are the downsides?
Forming expanding mesh is an industrial process of cutting and stretching, so tolerances are much bigger than for laser-cut or punched panels – which are accurate to +/- 1mm across a sheet. That said, skilled façade companies will design the sub-structure and use specialist brackets to compensate.
Expanded mesh is great for rectangular panels but cutting at angles can leave dangerous sharp points. Particular care must be taken during installation, and protective flashings incorporated into the design.
Not all expanded mesh is suitable for architectural façades. Strand width (the metal separating the holes) should be no less the 20mmm to retain structural integrity, while metal thickness should be at least 3mm.
Fortunately, a façade specialist can help guide you through all these important considerations.
Expanded mesh and the importance of free area
Car park design is an increasingly important sector in construction, with architectural façades an integral part of the design. Perforated panels are common, but expanded mesh has an advantage when it comes to meeting ‘free area’ regulations for ventilation.
Any perforated panel requiring more than 40% free space (essentially the total area of the holes) will need stiffeners for strength. Above 40%, and expanded mesh may be a better and more cost-effective option.
Read our car park guide
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