Exterior Insulated Finish Systems (EIFS)
What is EIFS?
EIFS stands for an Exterior Insulation Finishing System. Essentially, what this means is that EIFS is a synthetic stucco system, which is applied to the exterior of residential or commercial buildings. EIFS was originally designed to be a complete (100%) water barrier system, which was applied to buildings. The goal of the system was not only to seal and insulate the exterior of buildings but to also be customizable (in any way desired) to be aesthetically pleasing.
How is the system applied?
The framing of a building is overlaid with a substrate such as gypsum or wood boarding. A Styrofoam board known as EPS (Expanded Polystyrene) is then attached to the substrate with adhesive and/or mechanical fasteners. A base coat of a cementious substance is then layered over the EPS boards and fiberglass mesh is then imbedded into the base coat for reinforcement. Finally, a finish coat is laid over the mesh/base coat.
What is the design flaw with EIFS?
The EIFS system was not designed with the ability to drain water that penetrates into the system. The water that enters into the system becomes trapped and sets up a cycle, which ultimately leads to rotting of the material behind the EIFS system (in some cases this includes rotting of the buildings framing system). This all can lead to major structural damage to a building. Additionally, the moisture trapped behind the EIFS sets up a perfect environment for pests such as termites and carpenter ants.
What contributes to the accumulation of moisture behind the EIFS system?
Improper installation. Since the EIFS system is inherently flawed (its inability to drain water which has penetrated the system) the success of the system depends upon the installation. If the builder does not follow the manufacturers guidelines exactly the system is often doomed from the start.
What are common sites of error during the installation of EIFS?
- Improper sealing of the joints around windows and doors.
- Lack of kick out flashing on the roof
- Improper fastening of the EPS boards to the substrate
- Lack of back-wraping of the mesh
- Improper termination of the EIFS system below grade
- Horizontal surfaces on the EIFS system where water can collect
- Lack of cap flashing or cricket flashing
- Lack of sealant around EIFS penetrations such as water spickets, A/C piping, utility lines, lighting fixtures, etc.
- Decorative trim which is improperly fastened to the EIFS system
Can the EIFS systems be remediated once moisture intrusion has occurred?
Yes. The system can be repaired but it takes a well-trained builder to remove the existing EIFS system in the areas that the moisture has been detected, repair the underlying structure, and then replace the EIFS system correctly.
What is the purpose of a certified EIFS inspector?
EIFS inspectors are specifically trained in how to detect/locate areas where the installer has improperly installed the EIFS system. The trick is to use an EIFS inspector to locate these problems before moisture has already penetrated behind the system. If it is already too late and the EIFS system has been compromised an EIFS inspector can accurately locate the spots where the system has to be repaired. Finally, an EIFS inspector also can act as an independent 3rd party who can oversee the installation of an EIFS system from start to finish in order to correct problems before they ever get a chance to become a source of water intrusion.