What
are Exterior Insulation and Finish Systems (EIFS)?
The most common
type of Exterior Insulation and Finish Systems, sometimes referred
to as synthetic stucco, typically consists of five components: adhesive,
insulation board, a base coat into which a fiberglass mesh is imbedded,
and a decorative finish coat in the desired color. This type of system
is called a face sealed barrier EIFS and resists water penetration
at its outer surface. It is not intended to drain water that gets
behind it. It differs from other types of cladding that have a weather
resistive barrier behind the cladding and/or may have air spaces between
the cladding and substrate.
There are many
types of cladding materials that appear like stucco. Traditional stucco
is made of cement and is different than exterior insulation finish
systems cladding which use a foam plastic insulation board, a polymer/cement
base coat, glass fiber mesh and a polymer modified finish coat. Other
types of "hybrid" stucco include direct applied polymer/cement base
coat to a substrate, or traditional stucco with an acrylic finish
coat.
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How
does water enter behind the EIFS?
Interfaces between
EIFS and dissimilar materials are a common source of water intrusion,
not the EIFS lamina (base and finish coats). The most frequent source
of water intrusion is windows. Water frequently enters the EIFS at
window locations via two ways: 1) either the joint around the perimeter
of the window; 2) through seams and joints in the window construction
itself. Large quantities of water that can result in some of the most
severe damage have frequently been discovered entering behind where
a roof meets and terminates at the lower edge in a wall. Other potential
sources of water intrusion are chimneys, decks and any other penetration
of the EIFS lamina.
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Why
does water intrusion occur behind EIFS and why is it important to
discover it?
Water intrusion
occurs in a number of ways, through and/or around building components
such as windows, doors, gable vents, penetrations, variety of flashing
and construction details. Water intrusion also occurs when maintenance
of these components and other critical areas like chaulk joints, is
ignored. It is important to discover the occurrence of water intrusion
as water can enter behind the cladding and wet unprotected substrate
(sheathing), and in some cases the wood structural members. Depending
upon climate and the overall makeup of the wall assembly, the wall
may not readily dry out. As water intrusion continues to occur undetected
in a particular area, it can accrue to levels substantial enough to
cause damage. Early detection of water intrusion is the key to minimizing
or preventing such damage.
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Is
the location of water entry visible and is the damage visible?
No. The location
of water entry is often difficult to see, and the damage to substrate
and structural members behind the exterior wall cladding frequently
cannot be detected by visual inspection.
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Should
I have my EIFS home periodically checked for elevated moisture levels?
Yes. Testing
should be done at least annually. A combination of two moisture meters,
non-invasive meter that scans through the wall for the presence of
moisture without penetrating the EIFS lamina, and a probetype meter
that penetrates the EIFS lamina and gives moisture readings of materials
in contact with the probes should be used. Only a professional experienced
in EIFS water intrusion inspections should perform this test. Testing
is recommended to be conducted in accordance with the latest edition
of Moisture Testing Guide for Wood Frame Construction Clad with Exterior
Insulation and Finish Systems that is published by the New Hanover
County Inspection Department in Wilmington, NC.
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Can
damaged homes be repaired and does the EIFS cladding have to be removed?
Any repair method
undertaken should render the house in a serviceable condition. Performance
criterion used to determine if a serviceable condition is being sustained
is a moisture assessment. Such a condition exists when damage or excessive
moisture is not detected behind the EIFS cladding. This may be true
even if the EIFS manufacturer's standard specifications and construction
details were not originally followed. Localized removal of EIFS may
be necessary to facilitate repairs where damage is discovered. Total
removal of the cladding may not be necessary.
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What
are the repair objectives?
The primary objective
of repair methods is to eliminate water intrusion. Repairs should
e made where elevated moisture or structural integrity of the material
is impaired. Where structural damage has occurred, those areas require
replacement of decayed lumber in addition to eliminating the source
of water intrusion. Areas of elevated moisture in the absence of damage
or decay may require no more than eliminating the source of water
intrusion. It has been discovered that undamaged but wet substrate
can dry out over time once the source of the water intrusion has been
eliminated. Repair methods should address leaks associated with but
not limited to:
