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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