Rainscreen Cladding
From Swikipedia
Introduction
Rainscreen cladding is a method of constructing walls in which the cladding is separated from a membrane by an airspace that allows pressure equalization to prevent rain from being forced in. It is mostly used for high-rise buildings or for buildings located in windy regions. The main objective of Rainscreen cladding is to utilize the effects of the wind to control rainwater and prevent it entering the building.
Brief Description
Rainscreen:
A Rainscreen diminishes the forces attempting to drive moisture into the wall and effectively ‘drain the rain’. They control powerful building wetting forces-gravity, capillary action and wind pressure differences.
Types of Rainscreens:
1. Simple Rainscreens: They rely on the airspace next to the drainage plane to quickly and freely remove water from the wall and are effective in climates with an annual precipitation of less than 60 inches.
2. Pressure-equalized Rainscreens (PER): They integrate porous exterior claddings, compartmentalized air spaces, generous ventilation, and watertight, airtight support walls. These are mainly effective in climates with an annual precipitation of 60 inches or more and serve as an advanced version of simple rainscreens.
Rainscreen Cladding:
Rainscreen cladding consists of a sub-frame and different finishes like ceramic tiles, reconstituted stone boards, ceramic granite based on a natural stone, high-pressure laminates, composite aluminium panels or fibre-cement board, or durable exterior woods.
Underlying Principles of Rainscreen Cladding:
• Careful design of ventilated cavities that use the pressure effects of the wind to dissipate energy of driven rainwater
• Properly designed drainage paths that collect and direct the water away from the cavity
Advantages of Rainscreen Cladding:
• Thermal bridging is eliminated because there are no interruptions caused by floor slabs
• Temperature fluctuations are minimized due to insulation on the outside
• Interstitial condensation is prevented as vapour pressure and wall temperature restricts condensation to the ventilated cavity
• Heat from the sun is dissipated so that the temperature is dispersed in the cavity and ventilated through openings
References:
http://whygreenbuildings.com/glossary.php
http://en.wikipedia.org/wiki/Rainscreen_cladding
http://www.rainscreenworks.com/
http://www.toolbase.org/Technology-Inventory/walls/rain-screen-exterior-walls
