Also known as: “Exterior Ventilated Cladding” , Ventilated Facade”, “Pressure Equalized Rainscreen Wall”,  and  “Rain Screen Cladding” among other terms.

So what is a rain Screen?:

rain screen-ipe siding at window

All rain screens include the following elements:

  • Vented or porous exterior cladding
  • Air cavity (a few inches of depth is sufficient)
  • Drainage layer on support wall
  • Rigid, water-resistant, airtight, support wall

pressure_rainscreen-Section detail

Advantages of a Rain Screen Assembly:

  • Energy Efficiency: Provides a passive insulation cavity that helps save energy.  When it is hot outside, this buffer zone behind the rain screen allows the hot air outside to cool off, shielding the interior of the home or structure from the thermal impact.  Likewise, in colder climates or when there is cooler weather in any climate, this air space behind the rain screen provides the same buffer zone to prevent the transmission of heat gain or loss which creates a more energy efficient design.
  • Moisture Management:  Air space between exterior cladding and drainage plane helps drainage and facilitates drying.  Moving air within the air gap diffuses water vapor and prevents condensation and moisture from forming within the panels.
  • Solar Protection:  The thermal comfort is improved inside the building, preventing overheating in summer, as it facilitates the transpiration of the façade and reduces the amount of thermal energy that reaches the inside of the building.  The internal structure is protected from direct radiation and from the elements.
  • Acoustic Insulation:  As a compound system with several layers, including an air gap,  a greater noise absorption is created.

machiche rainscreen in los altos

Potential Issues

  • UV degradation of weather barrier
  • Insects nesting in air space
  • Detailing around windows
  • Weather-resistive barrier failure
  • Increased material and labor costs
  • Added installation time

 

Some good info and resources:

“The rain screen siding principle is straightforward: first build an outside wall and weatherproof it (building envelope), secondly construct an outer layer of siding (rain screen) to keep the weather (rain, snow, sleet,wind and sun) away from the inner wall. The air space in the wall cavity between the building envelope and the rain screen allows moisture to escape and also creates a passive insulation layer. 

Rain screen siding technology has been in existence since as early as the 12th century A.D. Some wooden stave churches in Norway that were built in the late 1100’s using early rain screen wood siding technology are still in existence today. Many Japanese temples were also built about the same time using similar rain screen siding principles.  

 http://www.mataverdedecking.com/understanding-rain-screen-siding/

 

Architects and designers seeking better moisture management and energy efficiency from the exteriors of their projects are turning to rain screens as a solution for both.

A rain screen is an exterior cladding infrastructure that sits away from a building’s outside wall’s weather-resistant barrier, creating an air cavity directly behind the cladding that helps to protect the buildings important weather-resistant barrier. This allows any moisture that may pass by the cladding to easily drain away from the building, and the air that flows between the cladding and the wall accelerates evaporation of any residual moisture. Rain screens also provide a solution for improving buildings energy efficiency by facilitating exterior insulation. ”  

http://www.knightwallsystems.com/index.php?page=what-is-a-rain-screen

rain-screen-siding-01

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