Five reasons to finish a façade with sheet metal

Thin profiled sheet metal allows a lightweight outer layer to be created. This can be advantageous for refurbishment or for cladding a framed structure. The supporting structure and the other layers must be included in the assessment. The low mass of the sheet itself does not remove the need to check the wall, the fixings and the wind forces acting on the façade.

The edges and corners of the building are particularly important. The fastening should correspond to the local loads, the height and the substrate. A solution from a small garage should not be copied onto the tall wall of an industrial hall. Lightweight cladding offers a benefit when the entire system has been correctly designed and can safely transfer forces to the structure.

Sheets of appropriate lengths allow regular sections of wall to be covered quickly. Planning the courses in advance reduces offcuts and accidental joints. The work nevertheless requires a level substrate and prepared flashings. The pace drops when the position of windows, doors or service penetrations is only determined during installation.

An insulated sandwich panel for walls can additionally combine cladding with insulation, but it is a separate solution from a single sheet metal panel on a supporting structure. Its installation requires proper lifting, interlocking joints and fastening. The choice of technology should follow from the function of the building. The installation time of the sheet alone should not be compared with the time taken to complete an insulated wall.

Trapezoidal sheet metal creates regular lines that can be used in the composition of the building volume. A vertical arrangement emphasises height, a horizontal one the length of the façade. Colour, profile height and gloss change the reflection of light. Before ordering, it is worth viewing a sample and a larger section of a completed project. A small swatch does not show the rhythm of the whole wall.

The installation direction must be approved for the specific solution. Water drainage and lap details must be taken into account. Not every roof profile is suitable without modification for every façade. The correct product data sheet and section drawing allow the material to be selected in accordance with its function. Aesthetics should draw on these principles rather than replace them.

In the event of damage, a selected section of cladding can often be replaced without dismantling the entire façade. The extent depends on the arrangement of the sheets, the fixings and the flashings. It is worth keeping the specification and the layout plan. This makes it easier to select a matching profile and to determine how to access the element requiring repair.

This does not mean complete resistance to impacts. Where there is intensive movement of vehicles or trolleys, additional mechanical protection may be needed. New sheet metal may also differ in shade from older material. Well-planned divisions and access to fixings make servicing easier, but they do not remove the need to care for the coating and respond to corrosion.

Metal cladding can form part of a ventilated façade with appropriate insulation and a layer protecting the interior. PIR insulation boards help where a low insulation thickness is important. Mineral wool may meet other fire or acoustic requirements. The choice of material depends on the complete solution, not only on the external surface.

The designed continuity of insulation, airtightness and the ventilation path must be maintained. The sheet metal alone is not insulation nor a layer that solves all moisture problems. The areas around the plinth, windows and corners require separate details. In a sandwich panel, correct interlocking joints and flashings perform a similar role. The principles of the two technologies must be distinguished.

Prepare a drawing of the divisions, the arrangement of supports and a list of openings. Select the coating for the environment and the cleaning method. Dark colours may increase thermal deformation, which must be taken into account particularly with long elements. Order compatible flashings and fasteners. Do not straighten a curved structure by over-tightening the sheets.

At acceptance, check the evenness, the connections, the condition of the surface and the completeness of the finishes. Remove swarf and films in accordance with the instructions. Plan subsequent inspection of places where deposits accumulate. The five advantages listed can produce a durable result if the sheet metal is part of a well-executed system. The choice of a fashionable colour alone will not ensure the quality of the entire façade.