In the mid-1990s, architects, contractors, and homeowners became aware of serious mold and mildew problems associated with barrier exterior insulation and finish systems (EIFS), an exterior wall facing. This knowledge pushed EIFS manufacturers to incorporate permeability into the design of EIFS. The first use of EIFS in the United States was in 1969. There were several advantages to this early EIFS design.
Specifically, it reduced energy consumption and air infiltration because it covered a building’s entire exterior wall space and eliminated thermal breaks in the insulation barrier. In the 1970s and 1980s, EIFS was used mostly on commercial buildings. Then, in the 1990s, there was extensive use of EIFS in residential construction. In fact, in 1994, 35 percent of new homes were clad with EIFS. Unfortunately, it was also around this time that architects, contractors, and homeowners became aware of the serious mold and mildew problems associated with barrier EIFS, mainly with residential homes constructed of wood.
Because EIFS commercial buildings are often constructed with masonry or concrete block, which is non-organic and does not absorb moisture, they were not as affected by mold problems. In response to the mold and mildew issues associated with EIFS, homeowners filed thousands of EIFS-related lawsuits. The lawsuits claimed that water accumulation behind the wall surfaces, caused severe mold problems, insect damage, and rot.
Consequently, insurance premiums skyrocketed for EIFS homeowners, while their homes values declined. During the 1990s, moisture issues within the walls of EIFS, and the resulting mold and mildew issues led builders to rethink the design of EIFS. EIFS should be air and moisture tight, but also permeable, and allow water to drain.
EARLY EXTERIOR INSULATION AND FINISH SYSTEMS
EIFS was initially designed to resist water penetration at the outer surface; however, the design had serious flaws. The first EIFS design leaked and lacked proper moisture diversion. It also used moisture sensitive (absorb and hold water) materials. Moisture infiltrated the EIFS design near the openings in the building envelope (doors, windows, etc.) and around sealants that broke down or cracked. When water got behind EIFS systems, it did not drain.
The combination of no provision for drainage and the use of moisture sensitive components made structures constructed with barrier EIFS susceptible to severe insect damage, rot, and mold problems. Importantly, in 1995 the American Institute of Architects (AIA) Task Force in Wilmington, North Carolina, investigated EIFS problems in 2009 residential homes. The study determined that it was not water penetration through the barrier EIFS that was the issue, but water retention. The early EIFS wrapped the exterior of the house in an energy-efficient blanket, but without a drainage plane, water got trapped in the system.
The discovery of mold and mildew in the wall systems of EIFS homes in the 1990s led EIFS homeowners to file hundreds of lawsuits against the builders, manufacturers, distributors, and the applicators of EIFS. Because of the many lawsuits in the early 2000s, it became difficult and expensive for EIFS homeowners to obtain insurance. In response, the EIFS Industry Members Association (EIMA) and the International Conference of Building Officials (ICBO) implemented tighter requirements to prevent moistures issues in EIFS.
These requirements led to the development of drainage EIFS. The new drainage system has a secondary moisture barrier and a drainage mat with weep holes in the bottom that allow the water to drain. In addition, the International Building Code (IBC) mandates application of a water-resistive barrier to EIFS. In recent years EIFS insurance has become relatively easy to obtain and reasonably priced. The reason for this change is due to a drop in claims against EIFS. In 2016, the EIMA manufacturing members reported the filing of only three litigation claims.
PROTECT YOUR EIFS HOME WITH BARRICADE R-WRAP® PROTECTIVE HOUSE WRAP
Application of Barricade R-Wrap® Protective House Wrap beneath an exterior insulation and finish system (EIFS) provides a secondary line of defense against bulk water penetration and reduces air infiltration. In addition, R-Wrap’s micro-porous “breathable” film allows moisture vapor to pass through it easily and won’t trap moisture in the wall cavity. It is a non-perforated polyolefin membrane that resists rain and acts as an effective drainage plane.
Barricade R-Wrap® Protective House Wrap is recognized and approved by all major building codes and has the following equivalency ratings:
- Building Officials Code Administrators International (BOCA) – Alternative to No. 15 asphalt felt, complying with ASTM D226, Type 1
- SBCCI – Air infiltration barrier and moisture protection barrier complying as a weather-resistive barrier to Federal Specification UUB-790a
- ICBO (Uniform Building Code) – Equivalent to Grade D building paper having a minimum water resistance of 60 minutes
Installing R-Wrap beneath EIFS reduces air infiltration and acts as an excellent weather-resistive barrier. R-Wrap® Protective House Wrap is made of non-woven polyolefin and possesses superior strength. Also, R-Wrap maintains its durability with special ultraviolet stabilizers that protect it from the sun’s harsh rays for up to 4 months. Application of R-Wrap beneath EIFS will prevent accumulation of moisture and the possible disastrous problems associated with mold and mildew growth.
WHY MOLD AND MILDEW IS A PROBLEM
Mold and mildew (mold in the early stages) are simple microscopic organisms called fungus. They are a natural part of the environment and thrive in moist places by digesting organic materials such as soil, plants and decaying matter. While mold is beneficial in the outdoors, it becomes very problematic to homes and buildings. Mold reproduces by spores, which float in the air. If the spores infiltrate the building envelope and land on damp organic material within a building (wood products, wallpaper, carpets, drywall, etc.), the mold can start to grow within 24 to 48 hours.
Mold is a problem in buildings because it digests and destroys organic material (e.g., wood). Mold also can cause mild to severe health problems to the occupants of the structure, such as eye, skin, and respiratory problems. Toxic black mold, or Stachybotrys atra., causes particularly severe health issues including nausea, vomiting, bleeding in the lungs and nose, severe respiratory problems, chronic fatigue, and more. Mold thrives on organic material and moisture.
Preventing moisture accumulation within the wall systems is critical to inhibiting the growth of mildew and mold and ensuring the durability of the structure and the health of the occupants of a commercial building or home.