1. EIFS - A Brief History
Insulation and Finish Systems 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. While similar in appearance to stucco, EIFS
is an exterior cladding system that consists of components and
installation requirements very different from traditional stucco
(see Figure 1 – Sectional View of a Typical EIFS Application).
EIFS also requires very different care and maintenance than its
“look-alike” cousin, traditional stucco.
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. In Europe, the use of EIFS on
stud/sheathing walls is rare, as most European buildings have
solid masonry walls. European concrete or masonry substrates can
function as exterior walls without the EIFS. European EIFS tend to
have thicker and coarser finishes, which provides for better
waterproofing. The systems used in Europe also feature the use of
less portland cement and a higher resin content in the base coat,
giving the system more flexibility and water resistance, albeit at
for EIFS was transferred to the United States in 1969, when Rhode
Island-based Dryvit Systems, Inc. introduced EIFS in the U.S.
During the oil crisis of the early and mid 1970s, EIFS becomes
popular with energy-conscientious builders and buyers, who
sometimes see energy bills halved. EIFS began by being used almost
exclusively in the commercial building market, and was only
gradually adopted for use in homes. By 1980, EIFS cladding
accounted for one-half of 1 percent of the residential housing
market, and by 1995 nearly 200 million square feet (18,580,608 m2)
of EIFS were being installed annually on exterior walls in North
Also, 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. While the
original problems were discovered first in North Carolina, it is
really a nationwide issue.
In March of 1999, the NAHB (National Association of Home
listed the most common problems they found that were associated
with water intrusion in EIF systems as being:
Windows, Doors, Electrical Outlets
Below Grade Installation
commissioned study went on to state:
". . .homes
surveyed ages two to six are experiencing structural damage
due to excessive moisture buildup within walls. The cause of
the moisture accumulation is rain water intrusion from a
combination of factors including: improper sealing at joints
and around windows, doors, and other penetrations; improperly
sloped horizontal EIFS surfaces; inadequate flashing at roof
lines, dormers, decks, etc.; and window frames that leak into
2. What Is EIFS (Exterior Insulated
While giving the
appearance of stucco, EIFS is actually a multi-layered wall system
that consists of the following components:
- Made of polystyrene (or similar material), which is secured to
the exterior wall surface.
- Applied on top of the insulation and reinforced with fiber
- Applied on top of the base coat giving a durable,
The first half of
the acronym, "Exterior Insulation" is derived from the fact that
the first component installed is a foam insulation board. The foam
board is mechanically and/or adhesively attached to the exterior
sheathing of the home. In this respect the foam board serves as an
exterior insulating layer. Over this foam board is applied a
synthetic base-coat material in which is embedded a fiberglass
reinforcing mesh. This is typically referred to as the
"base-coat". On top of the base coat is applied one or more
"finish coats". This is the exterior layer that gives the product
its stucco-like appearance. Hence the second part of the acronym
many advantages that other exterior finishes and sidings do not.
Chief among these are superior energy efficiency and great
design flexibility. As a matter of fact, studies have
shown that EIFS can reduce the air infiltration in a wall by as
much as 55%, when compared to standard brick or wood construction.
One should bear in mind that an EIFS system is a non-structural
component of the wall. In other words, it is not designed to be
EIFS employed a
approach to rainwater management, and was thus very susceptible to
failure. Because of these early problems, most EIFS now
incorporates some sort of a drainage plane to allow for moisture
drainage. Newer installations incorporating this design could be
due to the nature of the product and the realities of the
construction process, even newer drainage EIFS systems can
are often taken in the application of EIFS systems, causing the
primary face seal moisture barrier to fail and leak (lack of
proper caulking, flashing, etc.).
of the second line of defense is highly dependent on correct
detailing by the designer and proper installation by the builder
and his subcontractors. Very often, flashings, housewrap,
windows, doors, etc., are improperly installed.
EIFS does not breathe and will not allow trapped moisture to
evaporate easily, which can cause great damage over time.
(Exterior Insulated Finish Systems) rely on a perfect seal at the
exterior surfaces, they are susceptible to entrapment of moisture
inside the system. Water can enter the system where seams and
seals fail, where moisture migrates from inside the building and
where punched openings (windows, doors, etc.) are present. Because
of the low vapor permeability of the finish, water trapped behind
the EIFS cannot dry out quickly toward the outside of the wall
(see figure 1). Depending on the rest of the wall system
design and installation, there may also be limited drying
potential to the inside. Limited drying potential in combination
with high leakage potential can lead to moisture buildup inside
the wall, and eventually to mold growth and structural decay.
3. The Causes Of Most
clearly provides many advantages, what's the big deal? The basic
problem begins with the erroneous belief that homes can be made to
be “water proof”. The simple truth is, they cannot. For example,
even when applied by professional caulking applicators, All caulk
joints will eventually fail. . . .even those caulk joints made
under laboratory conditions. No residential windows
are fully waterproof. . . .they are designed and manufactured to a
water-resistant standard. Some water will always find a way
in. When it can't get out, you have a problem.
A. Why Can EIFS Be A
Homes clad with EIFS (Exterior Insulation and Finish
Systems) a.k.a. synthetic stucco have a very strong
tendency to retain moisture between the sheathing of the home and
the finish system. The design of EIFS, unlike other systems
(brick, stone, siding, etc.), does not allow the moisture to drain
out. The problem is water intrusion and entrapment in the wall
cavities. The moisture can sit in contact with the sheathing for a
prolonged period and rotting may result. Damage can be serious.
While a brick or stone wall will contain an internal
drainage plane behind it and weep holes along the bottom edge to
allow for water drainage, moisture intruding into the EIFS wall
cavities is more damaging because it cannot readily escape back
out through the waterproof EIFS exterior as quickly as it can
through brick veneer, stone, or cement stucco, leaving the
internal sheathing and wood framing vulnerable to rot and decay.
installation of EIFS depends upon keeping water out of the wall
cavities. Consequently, in an effort to keep the water out, an
industry-wide installation standard was developed that details
installation procedures to be followed. In conjunction with this,
the EIFS manufacturers then trained and certified applicators to
install their products and supplied them with materials which met
But, here is
where the system begins to break down, because unfortunately, the
manufacturers failed to take into account the realities of
Barrier type systems rarely work.
The EIFS external barrier system depends upon a perfect external
water barrier to keep water out of wall cavities. Since the
outer shell is the only barrier against water intrusion, it must
form a “perfect” barrier at “all times.” When
there are so many entry points for water intrusion in the
exterior shell of a house, this is an unrealistic expectation.
Lack of inspection and enforcement of standards. Most manufacturers, unrealistically expected that the
building industry on its own (including public inspection
departments), would maintain industry standards &
specifications, provide oversight, and provide inspection of the
EIF system as it was installed. Everyone thought that someone
else was minding the store, consequently, the vast majority of
EIFS applications nation-wide, have never been inspected.
Compounding this problem is the fact that the EIFS manufacturers
have failed to insist upon the very standards they helped
originate, be met by the applicators they supply materials to.
Evolution of application guidelines.
Another consideration is that guidelines for EIFS installation
have been evolving over the years. An example of this is below
grade termination of the EIFS. While not allowed by building
code, early on, it was allowed by some manufacturers
specifications. However, due to problems with this type of
application nation-wide, in 1996 Dryvit Corp (one of the
largest EIFS manufacturers), changed all of its specifications
to require an 8 inch separation be left between the EIFS and
soil (termite problems in the South & carpenter ants in the
North, moisture wicking up into the EIFS, frost damage,
inability of the EIFS to drain water away if it is buried,
etc.). Unfortunately, this type of new information has been
slow to “trickle down” through the information
chain (from the manufacturer
applicator). Some distributors even claim their
insulation-board doesn’t wick water, and consequently can be
placed below grade (experience shows that it does, however).
Leaks and damage are hidden from view.
There are few, if any, external visual clues to an early leakage
problem. As a matter of fact, it can take years for an
intermittent leak to evidence itself as damaged sheathing,
window leaks, rotted framing, mold growth, etc. Many insurance
companies, builders, and applicators may not take a leakage
problem seriously, until they can actually see the damage.
The reason for this “mind-set” is understandable, because
no one wants to be responsible to pay for repairs that may be
unnecessary. Unfortunately, by waiting until a problem is
noticeable as visible damage, the word repair can become the
word replace. What was once a relatively inexpensive repair has
become a very expensive replacement.
This is only a "North Carolina" problem.
Wrong, it's a national problem. It was discovered first
in North Carolina.
B. Problems With Secondary
Weather Barrier & Inability To Drain
wood-framed residential homes require a secondary weather barrier to be placed over the
sheathing before the exterior cladding is installed. This barrier
protects the home from incidental water intrusion and allows
moisture to exit the home by traveling on top of the barrier,
keeping the sheathing and structural members relatively dry.
Eliminating a barrier and rendering a substrate unprotected
invites trouble, no matter what type of exterior cladding is used.
Due to the design of the EIFS, a majority of EIFS clad
homes built before 1997 do not have a secondary weather barrier
placed over the exterior sheathing. A large number of EIFS
applications use an adhesive to fasten the two-foot by four-foot
insulation boards to the sheathing. If an adhesive is used to hold
the insulation boards to the sheathing, then a secondary weather
barrier cannot be used. Any water that infiltrates the system will
become trapped between the EIFS and the sheathing.
estimated that 95 percent of homes clad with EIFS in the United
States are barrier-type. Most barrier EIFS projects are adhesively
applied because it is less time consuming to install. Adhesively
applied EIFS prohibits a vapor barrier from being installed. It
also prevents many self-flashing windows from being installed
properly since the sill flashing must be cut off to accommodate
the adhesively attached foam board.
EIFS homes built
before 1997 have a greater chance for moisture intrusion problems.
Newer EIFS homes built since 1997 using “drainage EIFS” may have a
reduced chance of moisture intrusion, but are not immune.
C. Lack Of Applicator
be purchased from an EIFS distributor.
The manufacturer or distributor trains applicators and issues
certificates stating that the applicator has been properly
trained. It is the responsibility of the distributor to ensure
that EIFS is sold only to those certified applicators.
certification, training, and insistence upon maintaining standards
seem to have become almost meaningless in the marketplace. For
example, although most every manufacturer requires the use of
backer rod & sealant joints around windows and doors, and edge of
the foam should be back wrapped, these very important details
often omitted. Why?
Having said this,
still the best way to assure a high quality job is to rely on
members of the
Industry Members Association (EIMA).
EIMA members must meet all applicable building code testing
requirements and industry performance standards.
You can contact
EIMA at 1-800-294-3462, or write EIMA, 3000 Corporate Center
Drive, Suite 270, Morrow, GA 30260.
D. Deviations From
Deviations from Industry Standard guidelines during installation,
is likely the largest contributor to EIFS cladding problems. EIFS
application requires the strict observance of manufacturer
recommended specifications and guidelines, and involves meticulous
workmanship and attention to detail. When improperly applied, the
EIFS cladding does not perform its intended function and can allow
water to infiltrate behind the cladding, where it becomes trapped.
the lessons learned during the early years of the industry, around 1996 set of
"Installation Details" were developed by EIMA (EIFS Industry
Members Association), that have since become the industry
installation standard. Each manufacturer may have its own
specific requirements as well. EIFS Installation Details are
procedures outlined by the EIFS manufacturer that provide guidance
to the architect, builder and applicator as to the proper
installation of the product. All EIFS manufacturers have details
and procedures that builders and applicators are expected to
follow. Installation details are typically very similar among EIFS
products and EIFS manufacturers, but there are differences.
among some applicators is that the “Installation Details”
are designed for specific parts of the country, exposed to certain
weather conditions, and not to them. This couldn’t be farther
from the truth, and has led to some expensive repairs having to be
made. The Installation Details were designed to be used
industry-wide, and are applicable whether the installation is in a
northern cold climate, or southern warm climate. One should never
make the mistake of dismissing as being insignificant, even some
of the smaller deviations from the accepted industry installation
standards. Unfortunately, there is a long history of applicators
having done this in the past. . .to their great regret later on
when the bills come due to pay for replacing the entire exterior.
When installed properly, many EIF systems can perform well.
However, EIFS is a very unforgiving product and even the smallest
short-cut in installation standards and quality of components, can
lead to big problems down the road.
problem we face now is,
sometimes an individual contractor may fail to fully follow the
manufacturer's installation guidelines. Often times only a
portion of the guidelines are followed, materials from different
manufacturers are inter-mixed, etc. This can allow moisture into
the wall system. Once the moisture is in it can't get out, which
can lead to wood rot. Some of the more common installation
“short-cuts” are listed below:
Foam insulation placed below grade.
Prior to recent building code changes, the foam board insulation
used in EIFS was placed on the wall below grade. It was
discovered that foam in contact with the ground causes
conditions conducive to pest infestations (termites, carpenter
ants, etc.). With EIFS-clad homes, the visible evidence of
infestation is blocked from view by the exterior siding. In
fact, the exterior siding typically looks pristine and shows no
signs of any problems. Behind the EIFS cladding, pests can live
in a protected environment and then establish themselves inside
with placing the foam below grade is the ability of water vapor
to migrate upwards through the foam. When the temperature rises
at the transition from masonry to wood, the water vapor
condenses and causes water to settle on the sill plates and
exterior band joist. If this water does not evaporate quickly,
wood rot can set in and decay the structural members of the
Improperly flashed & caulked windows.
Window leaks account for the majority of water damage in EIFS
houses. The EIFS itself isn't usually leaking; instead, water is
entering between the window and the EIFS, or the window itself
is leaking water. The solution requires a window flashing that
works, as well as a correctly detailed joint between the window
and the EIFS wall. Wherever a window, a door, or an electrical
or plumbing fixture interrupts the EIFS surface, a proper joint
must be constructed, that integrates a reliable flashing into
the secondary weather barrier.
A very important component
that is often missing in window detailing is the
backer rod. The backer rod serves two functions: First,
it prevents the caulk bead from adhering to the back of the
joint, allowing the caulk to flex in response to thermal
expansion and contraction and other building movements. If the
backer rod is omitted, the caulk will adhere to the back of the
joint as well as the sides, limiting its ability to stretch and
guaranteeing premature failure. Second, it controls the
thickness of the finished application of caulk, which should
ideally be about half as thick as it is wide. More often than
not, though, the caulk and backer rod are never applied at all.
It is important to keep in mind that no residential windows are
waterproof, they are designed and manufactured to a
water-resistant standard. The very best windows allow some
water into the wall cavity through their own joints, and
“construction grade” windows may leak a great deal. The
quality of windows installed with the EIFS is directly related
to the amount of water that will infiltrate. For example, wood
windows perform poorly, while welded seam vinyl windows perform
substantially better than other window types. EIFS homes cannot
be made totally "water proof", and windows will leak.
Regardless of how well the backer rod/sealant method seals the
joints between window and the edge of the EIFS wall, windows
will leak at some point (even those caulk joints made under
laboratory conditions by EIFS industry engineers will eventually
Flashings missing or improperly installed.
are an important element in protecting your house from leakage, and should be utilized to properly direct water away
from the structure. Some of the more common locations where
they are required are: deck ledger boards, kick-out flashing at
roof / wall intersections, at window and door heads, headers and
other horizontal surfaces, etc. All too often, flashings are
not installed, or installed improperly.
Roof termination. EIFS should be held off of roof a minimum of two (2)
inches and backwrapped.
Expansion joints at dissimilar materials. Expansion-joints should be used where EIFS
terminates, or meets a dissimilar material. The typical
expansion joint is a flexible, watertight joint utilizing,
backer rod and sealant. Expansion joints are typically 1/2 inch
Where the foam
substrate terminates, it should be backwrapped, in order to
provide for proper protection of the foam. Backwrapping also
provides for improved attachment of the substrate to the
Horizontal Surfaces: Trim Bands Quoins.
There should be
no horizontal (flat) surfaces. All surfaces should slope away
from the structure.
applicator is responsible for the application process-attaching the foam insulation
to the substrate, applying the fiberglass mesh, embedding the
fiberglass mesh with base coat and applying a finish coat. EIFS
installers have little control over construction details designed
to prevent water intrusion into wall cavities from roofs, even
including those details which are required by some state building
codes and by the specifications of the EIFS manufacturers. Many
details outlined by manufacturers require the services of other
tradesmen. A typical EIFS applicator does not install backer rods
and sealant, but should install the EIFS so that it is possible to
install these critical components. The builder is responsible for
subcontracting the backer rod and sealant components. Flashing
around windows, doors, decks, chimneys and roofs is the
responsibility of the builder and his roofer. Unless the builder
required the roofing subcontractor to install step flashing and (EIFS
required) kick outs, it probably was not done.
applicator should recognize
improper flashing and not continue the application process until
the problem is corrected. Unfortunately, this also slows down the
overall building process. . .costing the home builder extra
money. It doesn’t take an applicator long to recognize that an
unhappy home builder may NOT call him to bid on the next
project. According to the National Association of
F. Pressure Differentials
is basically a face-sealed system.
The system relies on a water and airtight seal over the entire
wall system. When this is achieved, an air cavity is created
between the exterior sheathing behind the EIFS and the interior of
the home. Positive air pressure changes caused by wind on the
exterior of the home create a negative pressure in the wall
cavity. Any breach in the barrier EIFS system will force air
through that opening and into the wall cavity. When rain is
introduced in this scenario, water (in its liquid form or as
vapor), not air, is forced through any breach in the barrier EIFS.
Many researchers indicate that the difference in pressure
differentials is responsible for the majority of the water
intrusions in face-sealed systems. Other wall claddings such as
brick, lap siding, shingles and traditional stucco allow air to
infiltrate, thus rendering the positive force applied to the
building to be balanced.
G. Lack of Care and
The beautiful architectural designs made possible by
synthetic stucco systems make these homes very desirable and
marketable. It is critical, however, to carefully maintain these
systems to prevent water intrusion and deterioration. It is very
important that the six following steps be followed to protect your
Annually inspect all sealant
around windows, doors, penetrations through the EIFS, EIFS
transitions (such as EIFS to brick, EIFS to stone), and stucco
terminations (at roof, at grade, at patios or walkways). Arrange
for prompt repair of any areas of caulk that is split, cracking,
crazing or is losing adhesion. Also, promptly repair any cracks in
Any leaks, cracks, areas of discoloration,
mold or mildew should be promptly investigated by a certified EIFS
inspector. Repairs should be proper and prompt.
Anytime you make a penetration through the EIFS
such as to mount a satellite dish, add shutters, new wiring,
cables, plumbing, security systems, etc., the perimeters must be
sealed with a quality sealant approved for EIFS.
Modifications, additions or renovations
(including roof replacement) to the structure of any kind should
be inspected by a qualified EIFS inspector to ensure waterproofing
of critical details is properly performed.
of the surface is necessary to maintain its appearance and prevent
permanent staining. Pressure cleaning equipment must be calibrated
to the EIFS manufacturer’s recommended pressure level (low) to
prevent damage. Select a firm with experience in cleaning these
EIFS systems. There are no products that are totally maintenance
free, and EIFS is no different.
I would recommend setting up a maintenance schedule with an EIFS
specialist to carefully inspect the exterior for damage, about
every 1-2 years. Any needed repairs should be made at that time
(usually just re-caulking, etc.). EIFS is the type of system
where it is very important to catch any problems early-on.
with the above noted maintenance schedule, you should contract
with a qualified specialist (i.e. home inspector, etc.), to
perform a complete surface scan of the exterior, on a regular
basis (about every 2-3 years or so). This is performed using a
very sophisticated instrument that can detect areas of hidden &
trapped moisture beneath the surface of the EIFS. Again, it is
important to catch problems early-on.
My own experience
in the field, actually inspecting homes with EIFS, supports the
findings of the NAHB study. I have seen very few homes where
the installation contractor has followed all the industry
guidelines and specifications. This doesn't mean that the
EIFS has failed in all these homes. . .it means that the EIFS is
at greater risk of failure and eventual leakage.
Hire a trained
professional to inspect your house, and give you an assessment as
to any needed repairs.
Is an EIFS problem repairable?
Many times, yes. .
.if the problem is caught early. Many homes only require minimal repair (if any at all),
in many cases under $1,000 - 2,000. Some homes, however, have
required a complete removal of the EIFS, costing thousands of
What can I do to protect my investment?
Hire a trained
to inspect your house, and give you an assessment as to any
needed repairs. This should be done every year. Start a
preventative maintenance program. Often, only simple caulking
will need to be done, and some years nothing at all.
There is no such
thing as a maintenance free siding material.
EIFS is no different, and will require maintenance and periodic
repair on your part.
Florida Master Home Inspectors, Inc. Serves:
Raton, Boynton, Delray,
Green Acres, Hobe Sound,
Hypoluxo, Jupiter, Lake
Worth, Lantana, Loxahatchee,
Manalapan, North Palm, Palm
Beach, Palm Beach Gardens, Royal Palm, Riviera Beach,
Tequesta, Wellington, West