Rain screen wall construction involves an exterior skin that acts as a moisture repellant and a backup wall that is caulked but never exposed to the elements. Insulation is located between the backup wall and the exterior skin/screen. Air is permitted to circulate within the wall cavity which keeps the insulation dry and allows the moisture to evaporate, thus eliminating condensation problems and preventing the buildup of mold.
The general consensus used to be that an exterior single seal would protect the interior environment of a building. Today, building forensics has taught us that moisture latent air is the major culprit of exterior wall failure.
Is rain screen a product?
No, it is a method of wall assembly that moves the dew point into a ventilated, pressure-equalized space. This allows the condensation that results from the dew point to evaporate, thus leaving the insulation dry and free from trapped moisture (mold).
Is it more expensive?
No, the rain screen wall utilizes the same components of the conventional wall, it just places them differently. Instead of putting the insulation inside the stud wall, rain screen systems place the insulation to the exterior of the substrate wall. This allows the insulation to remain dry.
Why is rain screen beneficial?
Many reasons. First, the building becomes more efficient since the insulation can be applied in an uninterrupted manner. This minimizes thermal conductivity and ‘cold spots’ on the wall. It opens up the stud wall for electrical wires while keeping the insulation in its own plane.
Rain screen walls require far less maintenance because the cladding system (which can be any product) is not sealed. The joints are left open, which allows the air to come through. This air flow is what creates an equalized pressure. The open joints require no sealants, thus lessening the maintenance required and keeping the face of the cladding clean. Rain screen systems also allow interior trades to start work sooner creating a more efficient project schedule.
Do rain screen systems help with sustainability?
Yes. Rain screen walls not only provide a healthier, more efficient wall, but they also allow you to select from a vast array of products that feature high levels of post consumer recycled content. To learn more about rain screen systems, please request one of our AIA accredited Building Envelope Technology presentations.
© 2010 Architectural Wall Systems co. All Rights Reserved