What
are EIFS?
Exterior
Insulation and Finish Systems (EIFS) are multi-layered exterior
wall systems that are used on both commercial buildings and
homes. EIFS were introduced in the U.S. almost 30 years ago
and were first used on commercial buildings and then later on
homes. EIFS typically consist of an insulation board made of
polystyrene foam (which is secured to the exterior wall surface
with an adhesive and/or mechanical attachments), a water-resistant
base coat applied on top of the insulation and reinforced with
fiberglass mesh, and a finish coat typically using acrylic co-polymer
technology. This type of system is often referred to as artificial
stucco.
The
Potential Problem with EIFS...
The
potential problem with EIFS is that moisture can get trapped
behind the highly water resistant material with no way out.
This can cause the framing to rot and foster the growth of mold
between the exterior and interior walls. Damp and rotting wood
is also a prime target for subterranean termites. It should
be stated that the potential for these conditions exist with
any type of exterior siding product be it brick veneer, wood,
or vinyl siding. The potential for this condition with EIFS
however can be exacerbated by its superior water resistance.
Once moisture gets in, regardless of its origin, it usually
has no escape.
The
main locations where water tends to infiltrate into the framing
structure of a building using an EIFS is around doors and windows,
where the roof connects to the EIFS (roof flashing), and below
extended exterior deck connections. Also, any moisture from
within the home trying to find a path out will likely be thwarted
by the EIFS.
The
EIFS industry has been plagued by class action, and individual
lawsuits (particularly in humid climates). The public's confidence
in the products have been shaken to say the least. The lawsuits
contend that the problem is with the nature of the product and
the manufacturers contend that sloppy installation and poor
maintenance are the culprits.
Regardless
of who is "right", its clear that homes with EIFS
require special scrutiny during inspection
So now we can say it, but what is EIFS and why do we care? EIFS
stands for Exterior Insulating and Finishing Systems. It is
sometimes referred to as Synthetic Stucco. Its use increased
sharply in the 1990s. In North America about 300, 000 homes
have an EIFS exterior. We care because EIFS has been connected
to concealed rot in wall cavities.
What
Is Happening?
Rain water appears to be getting into the wall systems through
imperfections in the stucco. These include joints around windows
and doors and penetrations from railings, wiring, plumbing,
vents, etc. Once water gets behind the system it gets trapped,
leading to mold, mildew and rot of the sheathing, studs, flooring
and other framing members. EIFS houses often look good until
sections of the wall are removed revealing concealed damage.
The damage can take place within the first few years of the
home's life. As most of the damage has been found in houses
in coastal areas, some have suggested that condensation is a
problem; however, since the most severe damage seems to show
up around wall penetrations, condensation does not appear to
be the culprit. The worst damage is often found below and beside
windows.
Solutions
There is little that can be done on existing systems short of
residing or paying fanatical attention to keeping the water
out. Chaulking and flashing maintenance should be a high priority
for people with synthetic stucco houses. In the very newest
installations, contractors are using building paper or
housewrap behind the insulation to protect the sheathing. In
addition, the newest installations are designed with a drainage
system behind the insulation to allow any water which does get
in, to
drain out. This is not unlike the drainage system found in a
brick veneer home. These improvements should work but only if
they are well constructed.
