Rainscreen

A unique method of cladding or over cladding all types of buildings by providing a cold, ventilated façade which protects the external fabric of the building against the elements.

The rainscreen panels are normally secret fixed to a lightweight support structure which is secured to the building’s wall to create a cavity between it and the façade – insulation is applied to the external wall or within a tray/stud system. Rainscreen systems offer stunning solutions for the external cladding of buildings and are suitable for new build or refurbishment. They offer excellent whole-life costings due to speed of installation and low maintenance requirements.

A rainscreen façade is a cladding applied either during primary construction or as an over cladding to an existing structure. Rainscreen cladding consists of an outer weather-resistant decorative skin fixed to an underlying structure by means of a supporting grid, which maintains a ventilated and drained cavity between the façade and the structure. We use a range of metal and metal composite materials (MCM) for our rainscreen cladding systems. MCMs consist of two thin skins of aluminum or other metals such as copper, zinc and stainless steel continuously bonded under tension to either side of a thermoplastic or mineral core.

Rainscreen façades are not normally sealed and a ventilation cavity of at least 25mm is allowed immediately behind the cladding panel. Insulation can be positioned within the cavity and openings at the top and bottom of clad areas allow for evaporation of moisture vapour and ventilation/drainage. A ventilated rainscreen incorporating insulation will allow the building fabric to breathe without the risk of interstitial condensation or structural decay. External wall insulation used in this way is superior in performance as it eliminates the condensation risks associated with internal or cavity wall insulation. This is particularly important for refurbishment schemes. In new construction the use of back ventilated rainscreen cladding provides the designer with the opportunity to use economical single skin load bearing blockwork for infill walls.

The need for complicated damp proof membrane detailing is eliminated and there will be less risk of cold bridging. The air gap provides ventilation and depending on the design of the rainscreen, in conjunction with ventilated panel joints, it may also assist in providing pressure equalisation across the outer skin. Fully pressurised and compartmentalised (zoned) systems control airflow locally and are usually used on high performance, multi-storey developments. Where lower performance is required, for example in low rise structures, then a similar cassette panel system, although not fully pressure equalised, performs well.