Exterior Insulating
Finishing Systems (EIFS) has changed the architectural landscape of residential
and commercial neighborhoods everywhere. However, businesses looking to build
or retrofit with EIFS should be aware of the importance of proper installation,
periodic maintenance, and special hazard considerations to make sure that EIFS
is an effective design solution, rather than a structural or financial problem.
Popularly known as
“synthetic stucco” because of its visual resemblance to this more traditional
construction material, EIFS is an exterior covering for residential, commercial
and institutional structures of all types and sizes in all parts of the United
States.
The term EIFS incorporates the two main components of this covering
system – insulation that is attached to the exterior of the building and a
finishing system is that is applied afterward. Although EIFS was first
developed shortly after World War II, it has become increasingly popular over
the past three decades because it is relatively inexpensive for both new
construction and retrofitting, and provides effective thermal insulation.
Additionally, EIFS
provides a wide range of design options, including color, texture and shape.
Look around at hotels, office buildings, retail stores, restaurants,
supermarkets, strip malls and homes that appear to be stucco over masonry. Upon
closer inspection, they are most likely covered in EIFS. You can quickly
differentiate between EIFS and masonry with stucco by tapping on EIFS walls and
columns. Listen for the hollow sound. Also, the material will be slightly
pliable. By comparison, masonry with stucco produces a very solid sound when
tapping and will feel as hard as concrete.
Proper
Installation Critical to Long-term Performance
Because EIFS are proprietary
systems developed by individual manufacturers, there is no single formula for
every wall system. As shown in the figure on page 1, the general components
are:
- Metal studs or wood framing, often
including a cavity insulation such as fiberglass batts, for the surface
substrate;
- Surface substrate such as an
existing wall, or gypsum board, plywood, OSB board, or cement board;
- “Water drainage systems” will
include a drainage plane (cavity) that is created by an adhesive used to
attach the expanded polystyrene (EPS) to the substrate;
- EPS Insulation board that is
adhered as described above or mechanical attached to the substrate;
- Base coat applied to a reinforcing
glass fiber mesh on the face of the insulation board; and
- Primer and finish coating that can
be applied in a wide variety of colors and textures to create a stucco or
stone appearance, as well as many other kinds of appearances.
One important aspect
of EIFS design and installation is the prevention of water infiltration and
trapped moisture. There is an increased chance that the moisture infiltration
rate will exceed the drying rate within the wall, particularly in regions where
the climate is humid. When this occurs, the trapped moisture will begin to
deteriorate the wall. Trapped moisture within the wall cavity also can lead to
mold growth, rotting of wood framing and wall board, rusting of metal studs and
fasteners, and weakening of the EIFS components. If untreated, the effects can
propagate into the building causing odors to emit from rotting components and
mold, or damaging window and door frames, interior walls, and carpets.
In the 1970s and 80s,
EIFS systems were designed as a “barrier wall” system, also known as a “face
seal” approach. The premise was simple in theory – keep all water out of the
system by creating a waterproof wall system. However, due to the inherent
design of a multi-component wall system with hundreds or thousands of joints
requiring sealants, water often penetrated the wall system. In the mid–1990s,
the first “water-drainage” wall was introduced to the construction market. EIFS
requirements for barrier and water drainage systems are now included in the
2009 and 2012 International Building Code.
Small holes in the
EIFS; if left unrepaired, this can result in water infiltration and trapped
moisture.
This “water-drainage”
wall is designed to manage and remove any trapped moisture through the addition
of a drainage plane. Moisture barriers are placed over the substrate, and a
drainage plane is put in place by creating a space between the moisture barrier
and the EPS. However, while an improvement over its predecessor, the water-drainage
approach is not foolproof.
There are multiple types of materials that require
precise installation, and even the slightest undetected flaw can quickly become
the Achilles heel of the system. Attention to detail is required for the
installation of the multiple component materials, adhesives, and fasteners as
well as sealing properly around windows, doors, various joints, flashing,
corners, edges, ridges, wall-mounted air conditioner units, and wall
penetrations.
Moisture can be trapped if any of these aspects of installation
do not meet the manufacturer’s specifications. EIFS is more complex today than
the early forms of this wall system. EIFS contractors are now required to
install a multitude of building components with varying designs that necessitate
a large amount of installation knowledge, expertise, and precision. Building
codes require special installation inspections for EIFS unless it is installed
with a moisture barrier and drainage plane, or if the wall is masonry or
concrete.
Advice
for Hiring an EIFS Contractor
- Look for an established, licensed
and bonded professional that is a certified installer and a member of EIMA
(EIFS Industry Members Association).
- Meet manufacturer’s specifications
as well as the installation and wind requirements of the 2009 or 2012
International Building Code.
- Use building code approved
products.
- Third party inspections for
quality control is recommended.
- Request and check the contractor’s
references. Visit completed buildings and ask the building owners questions
about their satisfaction with the installation.
- Ask to see the contractor’s
certificates of insurance. Make sure that coverage for liability and
workers’ compensation insurance are current.
- Discuss available warranties from
the manufacturer and the contractor.
Maintenance
Matters
Thousands of existing
EIFS buildings are 20- or 30-years–old, and even older. As these buildings age,
UV rays, rain water, and temperature extremes can cause expansion and
contraction that wreak havoc on the exterior face of the EIFS, as well as the
sealed joints. Whether it is a face-sealed or managed water-type EIFS,
long-term weathering affects the integrity of the wall, and the older EIFS
walls get, the greater the potential for problems.
Along with installation,
proper maintenance of EIFS is critical to its performance and longevity. From a
short distance, an EIFS wall may look like it is very well sealed with no
apparent flaws; however, a close-up and thorough inspection can reveal minor
maintenance issues that can grow into big problems. Even though the system may
be designed to manage and drain trapped moisture, the best way to prevent
trapped moisture is to prevent it from entering in the first place.
Over time,
UV rays and continued weathering will eventually deteriorate even the most
resistant caulks and sealants, and small cracks and punctures can allow for
significant water intrusion.
A thorough preventative maintenance plan is
important to ensure the wall system performs as intended. Periodic inspections
of the entire wall system are needed to quickly identify and fix any cracks,
chips, holes, or punctures in any part of the wall, including areas that have
sealants.
Conduct
Visual Inspections
Small crack near this
wall-mounted AC unit can lead to leaks and trapped moisture.
EIFS with multiple
corners, edges, windows, joints, penetrations, and wall-mounted AC units.
Building owners can
conduct self-inspections. Simply walk the building’s perimeter and look
closely. While looking for cracks and punctures, also pay attention to anywhere
there are sealants at transition points such as joints, corners, ridges,
windows, doors, and any wall penetrations. Binoculars can help for taller
buildings. A camera phone can zoom in on areas that may be difficult to see and
show you close-ups of potential concerns.
Wind
and Fire Considerations
In geographic
locations that may be exposed to hurricanes, severe windstorms, and windborne
debris, wind-rated EIFS should be installed that includes a troweled adhesive,
which attaches the EPS to the substrate, forming a bond between the two
surfaces.
A proper amount of well-dispersed adhesive will distribute the wind
loads evenly across the entire substrate. Adhesives are also useful because
they can create a small void to allow for a drainage plane. There also are
wind-rated systems that include an adhesive for securing the EPS to the
substrate and mechanical fastening of the substrate to the framing.
By contrast, non
wind-rated EIFS will typically include mechanically fastened EPS, which
concentrates the wind loads at the point of fastening. In severe wind events,
mechanically attached EPS can pull over the fasteners and peel away from the
system. EIFS that includes mechanically fastened EPS is not recommended for
hurricane-prone areas.
Proper installation of EIFS also will influence wind
performance. For example, if there are not enough adhesives and overdriven
fasteners, the walls will not meet their wind-rated expectations. Additionally,
to protect against windborne debris, wind-rated EIFS typically will have a
thicker mesh installed over the EPS to resist the impact.
Fire is another
potential hazard associated with EIFS. The EPS insulation boards that are
integral to EIFS have the same composition as Styrofoam cups, and are extremely
flammable. Anytime the EPS is exposed, as shown in the photo below depicting a
corner section of a building, the potential for fire exists.
If an ignition
source, such as wildfire embers, sparks from a backyard barbecue or a lit
cigarette comes in contact with the EPS, it can ignite a fire within the wall.
When EPS burns, it liquefies and spreads very rapidly, which can result in a
serious fire within the wall cavity.
One common-sense
precaution for structures with EIFS walls is to maintain outdoor smoking
sections that are located well away from the building and include adequate ash
trays and receptacles. By contrast, it is common for hotels to have smoking
areas at their entrances and under porte-cocheres.
These areas often have
nicked and chipped EIFS due to luggage, carts and deliveries. Building managers
should pay special attention to walls with increased hazards. This includes
increased periodic visual inspections to ensure there is no exposed EPS, and
that proper smoking controls are being followed. Similarly, outdoor grilling
should be kept away from EIFS walls so that flames, radiant heat and embers do
not come into contact with EIFS walls.
Summary
EIFS has many architectural
and economic advantages, but it must be properly installed by qualified
contractors and properly maintained to remain an economic advantage with a
positive cost benefit over time. Manufacturer’s installation and maintenance
specifications should always be followed with meticulous detail.
Visual
inspections must be conducted on a regular basis to spot any problems early.
Taking some small preventive measures can go a long way toward preserving the
integrity of an EIFS wall, assuring both the visual appeal and the quality
performance you need for your business.
