Q: What is EIFS?
A: EIFS is a relatively new product to many
builders 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 base
coat, 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
or drainage track. 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: How can I tell if water build
up is in the 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 web site. 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.
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 EIFS drainage , 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.
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