E.I.F.S.

What is E.I.F.S.?

EIFS is Exterior Insulation and Finishing Systems, also known as Synthetic Stucco. It was first invented by a company called Sto Corp. and introduced to Europe in 1963. During the energy crisis of the 1970s, it was introduced into North America, since EIFS was considered an important cladding for energy conservation. Today, EIFS is the fastest growing residential wall cladding system, surpassing brick in many residential markets as the cladding system of choice.

Why is it so popular?

Few, if any other materials, have such a wide range of benefits such as superior energy efficiency, and an almost unlimited design flexibility. It also has excellent resistance to dirt, mildew and mold. A simple hosing down is all that’s necessary should the surface ever become soiled.

Is it suitable for our climate?

The application of EIFS is like wrapping the exterior of a home in an energy-efficient thermal blanket. By insulating outside the structure EIFS reduces air infiltration by as much as 55% compared to standard brick or wood construction, stabilizes the interior environment and reduces energy consumption. It also adds to the R-value of a home. The R-factor for EIFS is 3.8/inch compared with brick, for example, which is 0.20/inch. When combined with standard wall cavity insulation, this extra layer can boost wall insulation from R-11 to R-16 or more.

The Application Process

There are many different systems offered by various manufacturers, but in general EIFS wall systems consist of a wood frame wall covered with a sheathing such as plywood, or even gypsum board. Plastic foam insulation boards are glued or fastened to the sheathing. A 1/16 to 1/4 inch thick base coat is troweled on to the insulation. A glass fiber reinforcing mesh is embedded in the base coat. Finally, a finish coat is sprayed, troweled, or rolled on. The most popular finish is a medium texture since it hides the imperfections of the exterior of the house the best and is applied approximately 1/8 inch thick.   It is this finish coat that provides the colour and texture.

Many installations have no building paper or housewrap behind the stucco to act as a backup material. It is our opinion that a housewrap be installed between the substrate and the insulation board.

What are the problems with it?

In North America, EIFS was initially used almost exclusively on commercial, masonry buildings. As of 1997 EIFS accounted for about 4% of the residential siding market and 12% of the commercial siding market. It is among the most water resistant exterior surfaces you can put on a house. But, as with all claddings, EIFS must be correctly installed and properly detailed if it is to perform properly. Otherwise, moisture can get behind the systems and cause damage, just as it can with wood siding, brick or any other exterior.

EIFS has been connected to concealed rot in wall cavities. Rainwater appears to be getting into the wall systems through imperfections in the stucco. These include joints around windows and doors and penetrations from railings, wiring, plumbing, vents, etc. Once water gets behind the system it gets trapped, leading to mold, mildew and rot of the sheathing, studs, flooring and other framing members. The worst damage is often found below and beside windows. As a result, it is important that windows, penetrations, and adjacent construction be watertight, or be designed and installed to drain water beyond the outer surface of the EIFS.

Periodic maintenance should include thorough checking of the flashing and sealing to ensure that the building envelope remains watertight. Damaged or missing flashing should be repaired or replaced immediately. Also, cracked or deteriorated sealants should immediately be repaired, or removed and replaced.

How much does it cost to apply?

It varies from area to area, but generally the average cost runs from approximately $8.50 – $11.00 per sq. ft. compared to approximately $3.00/sq.ft. for vinyl siding and $10.00/sq.ft. for brick. A high impact mesh is often recommended for homes with children as it provides additional protection for the EIFS. It is generally installed from grade level to about 6 feet above ground and runs an additional $3.75 – $4.00 per sq. ft.

Does it include patterns?

The rich appearance of EIFS bears a resemblance to stucco or stone, but the systems are far more versatile than these and other materials. Not only does EIFS come in virtually limitless colours and a wide variety of textures, but they also can be fashioned into almost any shape or design. It is possible for skilled applicators to create all sorts of exterior architectural detailing. The designs are precision- cut out of insulation board, attached to the substrate or wall, then covered with the EIFS base coat, mesh and finish coat. These detailed moldings are sold per linear foot and are found to be quite expensive to the overall cost to provide a more pleasing architectural finish to the exterior.

Is there an organization for manufacturers of EIFS?

A non-profit trade organization was founded in 1981 comprised of more than 500 leading manufacturers, suppliers, distributors and applicators involved in the EIFS industry. This organization is known as the EIFS Industry Members Association (EIMA) and they promote the performance standards and develop specification guidelines for the industry. Manufacturers who are members of EIMA provide extensive specifications for all applicators using their products. EIMA also offers EIFS training programs. For additional information, EIMA can be reached at 1-800-294-3462, or by fax at 1-770-968-5818.

How many manufacturers of EIFS are there?

There are approximately twelve to fifteen manufacturers in the United States and none in Canada. Sto is the most popular, and others include Acrocrete, Inc., Pompano Beach, FL, and Retro Tek, Madison, WI. It is recommended that when choosing EIFS for your home you select an EIMA member manufacturer. They are able to provide technical support, documented product and system test results, as well as building code compliance information.