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The how
and why of EIFS moisture inspections, EIFS (sometimes referred to
as "synthetic stucco" had its beginning in Europe at the
end of Word War II, and quickly became popular as a building material
because of its ease of installation and cost efficiency. It was
introduced to the U.S. market in 1969 but was not widely used as
a construction material until the 1980's. It was first used in commercial
applications, and became popular as a residential construction material.
Today EIFS buildings account for approximately
17% of the commercial market and approximately 3.5% of the residential
market. The first company to manufacture EIFS in the United States
was the Dryvit company, which is why EIFS is sometimes referred
to as "Dryvit".
The acronym "EIFS" stands for
Exterior Insulated Finishing System. EIFS is a non-load bearing
exterior wall finishing system that gives the building a stuccolike
appearance. The system consists of four components:
- Panels of expanded polystyrene foam
insulation glued or screwed to the substrate or vapor barrier.
- A base coat that is troweled over the
foam insulation panels.
- A glass fiber reinforcing mesh that
is laid over the polystyrene insulation panels and fully embedded
in the base coat and.
- A finish coat that is troweled over
the base coat and the reinforcing mesh. The base coat, mesh and
finish coat are usually 1 / 8 to 1 / 4 inches thick. This is also
called the lamina.
There are two basic types of EIFS currently
in use in the U.S., barrier and water-managed. Barrier EIFS is designed
to divert all water from the exterior surface. Water-managed EIFS
anticipates that some water will penetrate the surface and incorporates
redundant water-management features (flashing, weeping, drainage
plane and waterdurable substrates) to ensure that water that breaches
the exterior finish will quickly exit the system. Most EIFS clad
homes in the U.S. are barrier EIFS systems.
The advantage of EIFS as a finishing system
is that it is energy efficient and economical to install. Unfortunately,
barrier EIFS systems have been found to have problems, often serious,
with moisture intrusion. In 1995, building inspectors in Wilm ington,
North Carolina discovered severe moisture damage on hundreds of
EIFS clad homes in that area. Similar problems have since been discovered
on EIFS clad homes in other parts of the country, resulting in a
class action lawsuit against the EIFS manufacturers. In some cases,
removal of the EIFS cladding has revealed extensive water damage
to the framing, jeopardizing the building's structural integrity.
Because the EIFS system is watertight, water
that penetrates behind the EIFS sheathing does not readily evaporate.
The barrier EIFS system is designed to allow for small amounts of
water vapor, but the system does not allow larger amounts of water
to readily evaporate. Water can become trapped and can soak into
the substrate and framing. Unlike more traditional facades, there
is normally no secondary barrier (housewrap) installed behind the
EIFS to protect the sheathing or framing. Severe damage could occur
without any exterior signs. These problems can exist regardless
of the age of the building or the quality of construction. Some
of our inspections have revealed extensive damage to buildings'
substrate and framing, of which the homeowners were completely unaware.
If problem areas are identified, preventative measures can be taken
before damage occurs, or before it becomes extensive enough to jeopardize
the structural integrity of the building. Early detection and prevention
of moisture intrusion can save thousands of dollars in repairs later
on.
Water does not usually enter through the
EIFS system itself, but through penetrations in the EIFS. The most
common areas of moisture intrusion are around windows and doors,
at the intersections between the EIFS and the roof, and areas where
the EIFS has been penetrated by attachments such as mailboxes, shutters,
decorative molding, railings, deck attachments, vents, chimney caps
over EIFS clad chimneys, and utility lines and pipes. Proper attachment
of penetrations is essential to prevent water intrusion. EIFS systems
also depend heavily on sealant (caulking) to keep moisture from
getting behind the system. If the sealant is decayed, damaged or
missing, water intrusion may occur. Moisture intrusion may also
occur if the EIFS is cracked or damaged.
An EIFS inspection is intended to identify
areas of high moisture content in the sheathing and framing, to
identify areas where the substrate has already been damaged by water,
and to identify areas of potential moisture intrusion. Often, an
EIFS inspection will detect leaks that are not related to the EIFS
system at all. For example, our inspectors have located roof leaks
and leaks from shower enclosures during EIFS inspections.
There are standard inspection protocols
governing EIFS inspections, but each building must be evaluated
independently. The nature and scope of the inspection may change
according to what is discovered. The inspection may take several
hours, and may even span more than one day. Before the inspection
the buyer, homeowner, or other client is asked to complete a survey
detailing what specific areas of concern should be addressed, any
problems that have been seen, and other information about the building.
When the EIFS inspection occurs as a result of a real estate transfer,
the EIFS inspector should coordinate with the home inspector and
the termite inspector to share information and findings. After the
inspection, a customized report is prepared for the homeowner or
client, including recommendations about maintaining an EIFS building
to minimize the risk of water damage.
In a standard EIFS inspection a non-intrusive
moisture scanner is used to identify relatively high moisture content.
In areas where the scanner indicates a high moisture content a probe
moisture meter is inserted to test for the moisture content of the
substrate and to test for damage to the substrate. The probe moisture
meter is also used at random locations throughout the system, and
in areas where potential moisture intrusion commonly occurs, such
as near windows. A high moisture content in the probe reading indicates
that water intrusion has occurred, and may be causing structural
damage to the building. If the probe indicates that the substrate
is soft, this could be a sign that damage has already occurred.
The probe moisture meter will make small holes in the EIFS, which
are then s
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