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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