Advertising supplement provided by
EIFS (Exterior Insulation and Finish
System) is an insulating, decorative and protective finish
system for exterior walls that can be installed on any type
of construction. It is the only exterior wall covering that
insulates and provides weather protection in a selection of
shapes, colors, and textures that can replicate almost any architectural
style or finish material, or stand by itself as an architectural
finish. In 1952, two significant developments took place that
led to the development of EIFS in Europe. The first patent was
granted for expanded polystyrene (EPS) insulation board and
the first synthetic plaster, an organic plaster using water
based binders, was developed. The use of EPS and synthetic resin
materials together began in the late 1950s and in 1963 EIFS
was marketed in Europe. EIFS answered a need in the European
construction market for a material that could insulate older
masonry structures and enhance their appearance. The technology
for EIFS was transferred to the United States in 1969. EIMA1
was formed in 1981 to represent the common interests of the
industry. By 1995 nearly 200 million square feet (18,580,608
m2) of EIFS were being installed annually on exterior walls
in North America. In 1995, the industry suffered a setback when
a number of EIFS clad homes in the Wilmington, North Carolina
area were discovered with moisture damage behind the cladding.
The damage was caused by poor construction detailing and practices,
principally, the omission or improper installation of flashing
in violation of minimum standards of construction set forth
in building codes. A federal and several state class action
lawsuits were filed, only one of which was certified (in the
State of North Carolina). The North Carolina class action was
settled by manufacturers. In the year 2000, EIFSthe next
generation, was launched to propel EIFS into the next century.
Use the following learning objectives
to focus your study while reading this months
ARCHITECTURAL RECORD / AIA Continuing Education article.
After reading this article, you will be able to:
1. Compare traditional EIFS to EIFS/the
2. Describe the main drawback of EIFS/with
traditional moisture protection.
3. Identify construction detailing
to avoid water intrusion problems in EIFS.
A traditional EIFS (Figure 1) is a non-load bearing cladding
and consists of five components: an insulation board, an adhesive
and/or mechanical fastener to attach the insulation board
to a substrate, reinforcing mesh for impact resistance, a
base coat to embed the reinforcing mesh and to provide weather
resistance, and a decorative and protective finish coat. This
is the most popular type of EIFS and is classified as a Class
PB (polymer based) System by EIMA. It is lightweight, easily
accommodates aesthetic features such as decorative trim and
reveals, and, in general, it does not require expansion and
control joints like conventional stucco or masonry veneer.
Its main limitations are impact resistance, and it is a barrier,
or face seal wall design, which, in tandem with other barrier
componentswindows and sealantsresists water penetration
at its outer surface.
|Figure 1. A Class PB EIFS consists of five components:
adhesive, insulation board, base coat, reinforcing
mesh and finish coat. Together they function as
a decorative and protective insulating wall covering.
EIFS and Building Codes
While EIFS have been in use in the United States for more
than 30 years, they are not explicitly covered in model building
codes. For materials or methods of construction that are not
covered, building codes generally permit the use of alternates
by providing the building code official with the authority
to approve alternates with justification such as testing,
engineering analysis, or some other evidence of compliance
with the intent of the code. Such approval is generally granted
on the basis of evaluation reports written by model code evaluation
services. The evaluation report establishes the method in
which a system or product is to be used, limitations associated
with its use, and that it is an equivalent to the construction
materials/methods of the code. The evaluation report should
always be consulted when considering EIFS as the exterior
wall covering, as it not only provides a means to verify compliance
with the applicable code, but it is also evidence that the
product has been thoroughly tested and evaluated.
To obtain an evaluation report manufacturers must satisfy
numerous criteria published by evaluation services that verify
system durability, structural and fire performance, as well
as compliance with quality control programs. The use of foam
plastic insulation in wall construction, in particular, requires
extensive testing to verify performance. The IBC2 presents
the most comprehensive set of requirements, as it essentially
merges the requirements of other model codes into one book.
The basic requirements for the use of foam plastic in walls
are established in Chapter 26. This includes:
- Separation from the interior.
- Fire performance testing (see Tables 1D and 1E in this
||Figure 2. The photo illustrates
testing in accordance with UBC Standard 26-9. The
test replicates a two story structure with a fire
in an interior compartment and examines lateral
and vertical flame spread. The test is one of many
criteria set forth in model codes to evaluate the
performance of foam plastic-based wall assemblies.
It is one of a series of fire tests that qualifies
EIFS for use on buildings of noncombustible construction.