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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 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 is the problem with EIFS?
A: Prior to the late 1990's, most residential EIFS did not incorporate a
moisture barrier behind the system. This is now 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. 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 wet for long periods 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 houses we have inspected
have at least some structural damage caused by water leakage and entrapment within the
walls.
Q: So how can I tell if water is building up in my walls?
A: Only with a comprehensive 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 EIFS 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 acidentally 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.
There are also EIFS inspectors who rely on Infrared cameras to determine
wet areas behind EIFS. Just like with the Tramex WWD, the 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. They are prone to both
false positives and false negatives. IR cameras can be a very useful
scanning tool, 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 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
inspection.
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. 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 EIFS?
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. When properly installed, they
dramatically improve the performance over the older barrier EIFS. Of course, they will still be sensitive to proper installation, like any
siding system. 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
thousands of sites discussing the issues. Please remember to think critically when visiting any website.
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