Q: What is EIFS?
A: EIFS is a relatively new product which uses plasticizers to modify traditional
cement stucco and make it more flexible. This allows application in a thinner coating
which saves time and material. The system also includes an insulation layer that
improves system and building performance. The entire modern EIFS system consists of a
moisture barrier (usually), the foam insulation, the plastic-cement basecoat,
fiberglass reinforcing mesh, and finishes. EIFS stands for Exterior
Insulated Finish System.
Q: What's the difference between EIFS and Stucco?
Traditional cement stucco is applied in three relatively thick coats, to
a total thickness of nearly one inch. The "stucco" part of the EIFS is
generally less than 1/4" in thickness. But the picture is not nearly
as black and white as many people think. There are "polymer-modified"
EIF systems that are often 1/4"-3/8" thick, yet they are still considered
EIFS. Then, there are "One-Coat" stucco products that can be applied
in a single coating as think as 3/8", and these are generally considered to
be "stucco", and not "EIFS." Some contractors apply 2 coats of one
coat stucco to a total thickness of nearly 3/4". "Stucco" can be
installed over foam insulation, like EIFS. Much of the new cement
stucco being applied still uses foam trim build-out details that look just
like EIFS, and most modern cement stucco uses acrylic finishes, just like
EIFS. The truth is that EIFS and stucco constitute a spectrum of
similar products with similar installation requirements, performance issues,
and failure modes. In most of the discussion below, you can substitute
"stucco" for "EIFS" to understand that the testing of any system is
Q: What is the problem with EIFS?
A: Prior to the late 1990's, most residential EIFS did not incorporate a
moisture barrier behind the system. Systems without backup moisture
protection are referred to as "barrier EIFS." In order to protect the building from moisture intrusion, barrier EIFS must be perfectly
sealed at the outside surface. Any moisture that penetrates the outer coating can
migrate into the walls and cause substantial damage. Unfortunately, nothing is
perfect, and the material tends to leak. Sometimes it leaks quite a bit. The
weak point of most applications is the penetrations like windows, doors, electric and
other utilities, etc. Each of these is a potential leak. Even though most
manufacturers withdrew their barrier EIFS from the residential market in the
late 1990's, we still see these systems being installed now.
Q: How do I know if my EIFS is leaking?
A: First, it is important to understand that ALL EIFS is leaking. All
cladding systems leak, whether made from EIFS, stucco, wood, vinyl, brick, or
something more exotic. The important
question is: How Much? As long as a wall is built to dry faster than any leaks can
wet it, there can be few problems. Problems occur when the water comes in faster
than it goes out. Materials that stay too wet for too long tend to rot, to grow
mold, and eventually to fall apart. Here in NJ, we find that many walls show signs
of leakage and elevated moisture, but that the damage caused by these leaks is less severe
than in other parts of the country. Still, over 90% of the EIFS houses we have inspected
have at least some structural damage caused by water leakage and entrapment within the
Q: So how can I tell if water is building up in my walls?
A: Only with a comprehensive visual and moisture intrusion inspection. There are many
different methods and tools that can be used to identify potential trouble spots.
But regardless of how suspect areas are identified, you cannot know exactly how much
moisture is trapped without penetrating the cladding and directly measuring the moisture
content of the building materials inside. There is just no other way. This has
been established by a number of nationally accepted test protocols, including the one we
follow. You can see our test protocol by visiting the GAHI website. Their protocol states in
part, "The advent of the Tramex Wet Wall Detector has eased the process of
inspection. This tester will indicate areas with high or elevated moisture content. This
tester will not provide specific moisture content information. An intrusive probe is
required for the determination of specific moisture content. "
Some other inspectors are touting their "non-invasive" inspections. Be
very careful before deciding on this type of inspection. Almost Home also uses the
non-invasive scanner ( A Tramex Wet Wall Detector, or WWD) to identify wet areas within
the walls, but only as a part of the complete moisture evaluation service. The
manufacturer of the most popular scanner (Tramex) indicates in their user's manual that,
"When the WWD has been zeroed correctly on a dry area and set on the correct range
for the EIFS thickness, a higher than zero reading normally indicates higher moisture
content." Read this statement very carefully.
In order for the meter to behave "normally", the test technician must know
the thickness of the EIFS and the moisture content of the wall behind it. There is
no way to know these critical pieces of information without penetrating the EIFS for the
calibration step. If the meter was accidentally zeroed over a wet area, then the
technician would miss ALL other wet areas on the house. In addition, the
manufacturer says that higher readings "normally" indicate higher moisture
levels. It is common for metal inside the walls to provide a false positive reading,
indicating that moisture is present when in fact, there is none. We often encounter
high readings with the WWD and find satisfactory moisture levels inside the wall with an
invasive probe. The manufacturer also recommends in several places in their user's
manual that the WWD results be checked using a penetrating probe.
Q: What about infrared (IR) inspections?
In addition to the WWD, Almost Home uses IR cameras to aid in locating
moisture during our inspections. However, we do not rely solely on the
results of the IR inspection to determine whether or not there is moisture
trapped in the walls.
Just like with the Tramex WWD, the IR camera can
be fooled. The cameras are very sensitive to weather conditions (the
best images can often be taken only for an hour or so after sundown), and to
normal wide variations in field conditions. It is important to
understand that IR cameras are sensitive only to changes in surface
temperature - they cannot "see" moisture. Occasionally, moisture
inside the wall causes temperature differences on the outside, and the
cameras see that temperature difference. But they are prone to both
false positives and false negatives. They cannot differentiate between
moisture stored in the basecoat and finish, moisture stored in the foam, or
moisture in the walls behind the EIFS. Only water in the walls behind
the EIFS is likely to damage the house. IR cameras can be very useful
scanning tools, but again, you only know for sure how much water and damage
may be behind the system by inserting probes and measuring it.
The bottom line is that the very smart Engineers at Tramex and the IR camera
companies have not yet been able to
find a way that their equipment can accurately measure the moisture content of the walls
independent of invasive probing. What do the other inspectors know that the
manufacturer's own Engineers do not? Use of these tools is an important part of a
comprehensive moisture intrusion inspection, but it cannot alone give the complete and
necessary information you need to properly understand the scope of any moisture problems
the house may have. A house is a big investment, and EIFS problems can be expensive
to repair. Do yourself a favor and hire someone who performs a complete and proper
Q: When you talk about "penetrating the EIFS": just how
big a hole do you make?
A: The moisture meter uses two narrow probes that require holes the size of an ice
pick (about 1/8"). Many people in the industry refer to this as a "snakebite." After testing,
the holes are sealed with an appropriate caulk that is compatible with the color of the EIFS. Because of the texture of the material, the patches are generally invisible.
Q: Are there other problems beyond structural decay?
A: Yes. Some molds can cause injury or ill health to people sensitive
to them. There is a surprising amount of air exchange between wall
cavities and the indoor rooms in a house. The air currents can carry mold
into the living spaces of a house. There are currently no public
health standards concerning unsafe mold levels or unsafe types of mold, but a
prudent homeowner will clean up any known mold sites and eliminate the moisture
problems that allowed the mold growth. An industrial hygienist familiar
with mold exposure and cleanup can provide further information.
Q: If my walls are wet, do I have to remove all of the
A: Not necessarily. It depends very much on how wet they are, how long they
have been wet, and how much
area is affected. Corrections can range from simple caulking and sealing, to partial
removal and repairs, to complete removal of the system and structural repair to the walls
behind. A direct moisture measurement is required to make this decision.
Q: Is there a solution for the leakage problems?
A: Yes. All of the major manufacturers are now selling products that drain.
They use different approaches to provide a drainage plane behind the EIFS so
that any moisture that leaks through the outer barrier can drain away to the
base of the wall and seep to the outside. Traditional cement stucco has always
been installed over some type of building paper to help drain this water out of
the back of the system. When properly installed, the backup water
dramatically improves the performance over the older barrier EIFS. Of course, they will still be sensitive to proper installation, like any
Q: If I have drainable EIFS, can I still
have a problem?
A: Yes. Now that drainable systems have been on the market for 10 years or
so, we have had time to see them in action. When properly applied, they
work well. Unfortunately, many builders do not follow the manufacturer's
instructions, and if the backup water barrier is not done well, these systems
exhibit the same failure modes as barrier EIFS. We generally see less
leakage and damage with drainable systems than with barrier systems, but we have
now seen dramatic failures with both types. Again, a comprehensive
moisture evaluation is the best way to know how well your system is performing.
Q: Where can I go for more information?
A: You are welcome to contact us
directly. We do our best to provide fast and free responses. If you want to
hear the party line directly from the manufacturers, go to the EIFS Industry Member's
Association, EIMA. If you
want a homeowner's perspective, simply do a web search on EIFS - there are many
tsites discussing the issues. Please remember to think critically when visiting any website.