An exterior insulation and finish system (EIFS) is a type of exterior wall cladding system which is designed to insulate and finish a home at the same time. This system was developed in the wake of the Second World War, when European manufacturers were seeking a way of rapidly repairing damaged buildings and getting new buildings established in communities which had experienced substantial damages. A number of manufacturers offer EIFS, which is installed by a contractor who is familiar with the product.
Although this product is known as “synthetic stucco,” it actually does not bear very much resemblance to stucco, and while EIFS can resemble stucco, the finish can also resemble wood, brick, stone, and a variety of other materials. The materials in this product are also synthetic, rather than being natural in origin, like traditional stucco, and stucco has a very different look and feel when it is installed and maintained properly. The product comes in polymer based (PB) and polymer modified (PM) varieties, with PB EIFS being especially sturdy.
While EIFS is designed to be a complete system, a home with this product in place still needs flashing, framing, and other basic construction work. The application of the EIFS starts with an insulating layer classically made from expandable polystyrene foam, which is followed with an adhesive layer and a finish coat. When applied properly, the product creates an envelope which seals the building, retarding moisture and helping the building retain heat. However, if flashing and gutters are not properly installed, water can penetrate the envelope, and it may become trapped, promoting rot.
Basic barrier EIFS provides little in the way of drainage options, which can make it problematic in some climates and with some building materials. In fact, this product has sparked several lawsuits from people who were angry about the way it performed. Drainage EIFS, on the other hand, is installed over a membrane which promotes drainage. While the drainage membrane cannot compensate for an improperly installed product, it does allow moisture to drain, rather than collecting inside the walls.
In addition to being applied on site, an exterior insulation and finish system can also be applied in panelized form. In this case, panels are manufactured at a factory and shipped to the site for installation. This can reduce waste on a construction site and save costs when it is done properly, like other types of panelized and modular construction. People who are considering EIFS should research their options carefully, and find an experienced contractor who will provide appropriate advice and a competent installation.
By Mary McMahon
Ever since she began contributing to the site several years ago, Mary has embraced the exciting challenge of being a About Mechanics researcher and writer. Mary has a liberal arts degree from Goddard College and spends her free time reading, cooking, and exploring the great outdoors.