Rainscreen cladding is the attachment of an outer skin of rear-ventilated cladding to a new or existing building. The system is a form of double wall construction that uses an outer layer to keep out the rain and an inner layer to provide thermal insulation, prevent excessive air leakage and carry wind loading. The outer layer breaths like a skin while the inner layer reduces energy losses. The structural frame of the building is kept absolutely dry, as water never reaches it or the thermal insulation.
Evaporation and drainage in the cavity removes water that penetrates between panel joints. Water droplets are not driven through the panel joints or openings because the rainscreen principle means that wind pressure acting on the outer face of the panel is equalised in the cavity. Therefore, there is no significant pressure differential to drive the rain through joints. During extreme weather, a minimal amount of water may penetrate the outer cladding. This, however, will run as droplets down the back of the cladding sheets and be dissipated through evaporation and drainages.
By insulating the structural wall externally the following benefits are achieved:
Ventilated Façade (Rainscreen)
rainscreen is a new building solution with a growing importance in modern architecture, not only for technical features, but also for it's aesthetic appearance. This ventilated facade system relies upon the fixing of terracotta or ceramic tiles on an aluminium substructure, previously fixed to the construction facade. The horizontal joints between tiles are left open to the cavity area of the cladding zone allowing for ventilation. rainscreen is fast to assemble and requires no wet trades, in comparison to traditional construction.
The principle behind rainscreen
The variation in air density between external and internal temperatures induce a funnel effect, giving rise to a consistent, upward airflow within the cavity. This continuous flow of air offers several, distinct advantages;
The key to achieving a continuous airflow within the cavity is consistent and accurate dimensions, which is extremely difficult using traditional wet trade forms of constructing building façades. A rainscreen system is an open joint cladding system, designed around the principles of air behaviour within the cavity. Past experience has shown that the airflow within the ventilation cavity in an open joint system is more consistent and beneficial than in a closed joint system, even under the effects of wind pressure or suction and during heating or cooling of the air.
Modern Day Application
Rainscreen is an extruding terracotta and ceramic product using a mixture of natural clays, manufactured to the exacting standards of the 21st Century. This provides a unique range of standard and bespoke terracotta recurs and glazed finishes available in large, medium and small format sizes, making it the perfect façades solution for modern architecture.
Advantages of rainscreen
In summer, the ventilated cladding provides the building with a natural thermal shield, which protects against heat gain from direct solar radiation. The constant ventilation keeps an ambient temperature within the cavity on the external side of the insulating panel.
The natural circulation of airflow within the cavity helps to evaporate any moisture present due to either condensation or capillary action.
A ventilated façades provides a perfect long-term protection for the building against wind driven rain water and weathering agents, such as rain, ice and snow. These are one of the main causes behind exterior deterioration of any construction. Research shows that no significant rain or snow infiltration occurs into the cavity on ventilated façadess fixed to the building by means of open-joint technique, even if exposed to a strong wind pressure.