Page 211 - Construction Waterproofing Handbook

3.98 CHAPTER THREE
The original systems included an insulation board, base coat with or without fiber mesh
reinforcing, and a decorative finish coat of polymer-modified coatings. Little emphasis
was placed on termination and transition detailing, although designers expected the prod-
uct to provide a complete barrier envelope waterproofing system. While the product’s orig-
inal emphasis was on insulating and decorative capability, it soon became a standalone
cladding system in all types of structures. Building owners that loved the cost effectiveness
of the product reinforced this acceptance.
Unfortunately, the systems were designed and used in applications that would perform
poorly as a barrier system for the building envelope. Excluding the insulation thickness,
1
1
these systems are applied at 8– 4 in thick, and this thin application created multiple prob-
lems related to termination and transitioning detailing. For example, early applications
1
included areas where the sealant material was applied into joints a minimum of 4 in thick
1
when the coating was only 8 in. This resulted in the sealant material attempting to adhere
to the incompatible insulation material, eventually resulting in a loss of adhesion, failure
of the joint, and resulting leakage and envelope damage.
Damage was further exasperated by the finish coatings not being permeable, so that
once water or moisture entered the envelope, diverter systems were not included to exit
water back out to the exterior. The trapped water then caused wood rot, and rusting of other
envelope components.
Leakage problems became common and in certain areas of the country class-action law-
suits were filed against the manufacturers (e.g., New Hanover, North Carolina, case 96
CVS 0059) and in some areas of the country local building departments (e.g., Wilmington,
North Carolina) banned the systems. EFIS problems became so prevalent in the home
building industry that a consumer advocacy organization was formed (Stucco Home
Owners Committee [SHOC]) to share information about the systems, in particular the
problems related to water damage and envelope damage. Further complicating the situa-
tion was the fact that insurers began to exclude coverage for EIFS systems.
There is no reason not to assume that these problems are directly related to the 90%/1%
and 99% principles presented in Chap. 1, which state that the majority of leakage is attrib-
utable to problems in transition and termination detailing, not to the material or system
itself. To alleviate the problems, manufacturers, designers, and contractors have responded
with better detailing and installation practices to enable EIFS systems to perform properly
and successfully as an envelope component with sufficient waterproofing capability. One
only has to visit Las Vegas, Nevada and carefully view the multitude of envelope designs
capable with EIFS systems to understand their continued popularity with designers and
building owners.
While the thinness of application presents unique challenges in designing and installing
proper termination and transition detailing, the cost effectiveness of the system for build-
ing owners offsets any negative connotations of the required intricate detailing. EIFS sys-
tems require the same adherence to the 90%/1% principle as any other envelope
component or system.
The only major change to occur in EIFS systems in responding to these leakage prob-
lems is the increased usage of EIFS diverter systems as opposed to EIFS barrier systems.
Acknowledging that some water or moisture is likely to enter the systems for whatever rea-
son (including the 90%/1 % principle), provisions can be provided to drain this water back