Typical Modern Rainscreen Wall Construction
Conceptually, every exterior wall, in addition to supporting structural load must also be able to protect itself from weather. If it cannot, the moisture penetrating it will damage it or eventually, completely destroy it. The image to the left shows the components of good wall construction as per current best practices:
A) The rainscreen's function is to shed water.
B) The rainscreen is separated from the main wall structure by an air space, allowing for water penetrating past the rainscreen to harmlessly drain out.
C) A weather resistant barrier is anything that will completely repel external water, while permitting moisture from the interior side of the wall to permiate through it, protecting the structural and/or insulating properties of the wall.
D) Wall sheathing, masonry or conrete wall structure are what the weather protection system is attached to.
External Insulation and Finish System
Developed in post WWII Europe; EIFS is a generic class of non-load bearing, exterior wall cladding systems, providing exterior walls with a water resistant, insulated and very resiliant hard finished surface.
Whereas the typical rainscreen system illustrated above usually has brick or siding acting as the rainscreen, the EIFS system uses a thick insulating layer which is properly sealed with a base coat and finished layers of stucco. And, with the cost of energy ever on the rise, the added insulating value and lowered air infiltration afforded by this system, customers have generally been very pleased.
EIFS represents the very best stucco system the construction industry has to offer. Those who have installed it on their homes by a qualified contractor have universally noted an increase in comfort and energy savings, in addition to enhanced property value!
With all the benefits of the EIFS system one might conclude that it is the only solution to every cladding situation but few, if any system can offer a one-size-fits-all solution in every case. There are situations that require other systems to meet a desired performance specification.