RAS Engineering is a professional engineering company serving building managers and owners by providing advice, oversight restoration, and testing to ensure that all components of a build’s exterior and structure meet the standards necessary to provide quality durability and safe protection against the elements.
Damage Assessment on EIFS walls affected by Hurricane
EIFS is a multi-layered exterior wall system that provides both insulation and a decorative finish. It consists of an exterior lamina composed of acrylic-modified cementitious materials, reinforced by a fiberglass mesh, which is applied over an insulated substrate. The EIFS lamina varies in thickness and composition depending on the type of material used.
1. Polymer-Based (PB) EIFS
Polymer-Based EIFS typically features a lamina ranging from 1/8 to 3/16 inches in thickness. This layer consists of a mesh-reinforced base coat, made from a mixture of Portland cement and proprietary acrylic polymers, along with a colored, textured finish coat. The base coat not only serves as the waterproofing layer but also encapsulates the mesh on either side, ensuring durability.
Adhesion and Insulation
The lamina is adhered to a rigid board foam insulation, usually molded expanded polystyrene (MEPS), which is secured to the substrate through methods like:
Ribbon-and-Dab Method: Continuous adhesive lines around the perimeter with dabs of adhesive in the center.
Notched Trowel Method: Uniform application of adhesive using a notched trowel.
2. Polymer-Modified (PM) EIFS
Polymer-Modified EIFS features a thicker lamina, typically ranging from 1/4 to 3/8 inches. Similar to PB EIFS, it contains a mesh-reinforced base coat and a textured finish coat. However, PM EIFS often utilizes extruded expanded polystyrene (XEPS) for insulation, which is fastened mechanically to the substrate using screw fasteners.
PM EIFS is commonly used with plastering accessories, providing additional aesthetic options and structural integrity.
3. Water Management EIFS
Water Management EIFS incorporates advanced components to effectively manage moisture and prevent water intrusion. Key elements include:
Weather-Resistive Barrier: Fluid-applied, trowel-applied, or sheet membrane.
Drainage Plane: Composed of drainage composite boards or drainage channels.
Adhered or Mechanically Fastened Insulation: Rigid foam board insulation attached securely to the substrate.
EIFS Lamina: The final decorative and protective layer.
The critical components of this system include properly designed flashings, weep holes, and an effective drainage plane integrated with the weather-resistive barrier.
Benefits of EIFS
EIFS offers numerous advantages, making it a favored choice for building exteriors:
Energy Efficiency: The insulation properties of EIFS help reduce energy consumption by maintaining indoor temperatures.
Versatile Design Options: EIFS can be easily molded and finished in various textures and colors, allowing for creative architectural designs.
Durability: The materials used in EIFS provide excellent resistance to weather conditions, including moisture and wind.
Lightweight Construction: Compared to traditional stucco or brick, EIFS is lighter, reducing structural load and facilitating easier installation.
Cost-Effectiveness: EIFS can be more affordable than other cladding systems, offering long-term savings through energy efficiency.
Assessing EIFS: Level 1 and Level 2 Evaluations
Regular assessments of EIFS are crucial to ensure their performance and integrity. These evaluations can help identify potential issues like water intrusion, which could lead to more significant problems if left unaddressed.
Level 1 Assessment
A Level 1 Assessment involves data gathering and both noninvasive and invasive investigations.
Preliminary Data Gathering
The assessment starts with a thorough review of available documentation from the original construction, including:
Architectural and structural drawings
Project manuals
Product submittals and manufacturer specifications
This information helps establish the existing conditions and any potential issues with the EIFS.
Noninvasive Investigation
The noninvasive phase includes a visual survey of the EIFS, focusing on aspects such as:
Surface finish consistency (fading, chalking, worn spots)
Cracking or spalling of the lamina
Exposed mesh or foam
Condition of building sealants
Inspectors may use ladders or lifts to access different building heights for a comprehensive evaluation.
Invasive Investigation
Invasive methods include moisture testing and evaluating the integrity of underlying substrates. This may involve:
Moisture Probes: Checking for moisture levels in the EIFS and underlying sheathing.
Rigidity Checks: Assessing the rigidity of substrates to detect deterioration.
Selective Demolition: Accessing the back of the EIFS for closer examination.
Level 2 Assessment
A Level 2 Assessment is recommended when a more in-depth evaluation is necessary. It includes methods like infrared thermography and field pull tests.
Infrared Thermography
This non-destructive method identifies thermal anomalies that may indicate trapped moisture or energy loss. The results require careful interpretation and follow-up with moisture probing or selective demolition to verify findings.
Field Pull Test
The field pull test assesses the installation adequacy and wind load capacity of the EIFS system. It involves cutting into the wall, adhering a test board, and pulling it to measure the EIFS's resistance to wind loads. This test provides valuable data on the overall condition and anticipated performance of the EIFS.
Conclusion
Exterior Insulation and Finish Systems (EIFS) are an excellent choice for modern building designs, offering energy efficiency, aesthetic versatility, and durability. Regular assessments are crucial to maintaining the integrity of EIFS and preventing potential issues. By understanding the different types of EIFS and their benefits, building professionals can make informed decisions that enhance the quality and longevity of their structures.
For more information on EIFS, visit the EIFS Industry Members Association (EIMA), which provides valuable resources and guidelines for proper installation, maintenance, and assessment practices.
Understanding Exterior Insulation and Finish Systems (EIFS): A Comprehensive Overview
As the demand for energy efficiency and aesthetic appeal in building designs continues
EIFS is a multi-layered exterior wall system that provides both insulation and a decorative finish. It consists of an exterior lamina made of acrylic-modified cementitious materials, reinforced by fiberglass mesh, which is applied over an insulated substrate. The EIFS lamina varies in thickness and composition depending on the type of material used. According to the EIFS Industry Members Association (EIMA), there are three basic types of EIFS cladding:
Polymer-Based (PB) EIFS
Polymer-Modified (PM) EIFS
Water Management (Drainage) EIFS
1. Polymer-Based (PB) EIFS
Polymer-Based EIFS typically features a lamina ranging from 1/8 to 3/16 inches in thickness. This layer consists of a mesh-reinforced base coat made from a mixture of Portland cement and proprietary acrylic polymers, along with a colored, textured finish coat. The base coat serves as a waterproofing layer, encapsulating the mesh on either side to ensure durability.
Adhesion and Insulation: The lamina adheres to a rigid board foam insulation, usually molded expanded polystyrene (MEPS), secured to the substrate through methods like:
Ribbon-and-Dab Method: Continuous adhesive lines around the perimeter with dabs of adhesive in the center.
Notched Trowel Method: Uniform application of adhesive using a notched trowel.
2. Polymer-Modified (PM) EIFS
Polymer-Modified EIFS features a thicker lamina, typically ranging from 1/4 to 3/8 inches. Like PB EIFS, it contains a mesh-reinforced base coat and a textured finish coat. However, PM EIFS often utilizes extruded expanded polystyrene (XEPS) for insulation, which is mechanically fastened to the substrate using screw fasteners.
PM EIFS is commonly used with plastering accessories, providing additional aesthetic options and structural integrity.
3. Water Management EIFS
Water Management EIFS incorporates advanced components to effectively manage moisture and prevent water intrusion. Key elements include:
Weather-Resistive Barrier: Fluid-applied, trowel-applied, or sheet membrane.
Drainage Plane: Composed of drainage composite boards or drainage channels.
Adhered or Mechanically Fastened Insulation: Rigid foam board insulation attached securely to the substrate.
EIFS Lamina: The final decorative and protective layer.
Critical components of this system include properly designed flashings, weep holes, and an effective drainage plane integrated with the weather-resistive barrier.
Benefits of EIFS
EIFS offers numerous advantages, making it a favored choice for building exteriors:
Energy Efficiency: The insulation properties of EIFS help reduce energy consumption by maintaining indoor temperatures.
Versatile Design Options: EIFS can be easily molded and finished in various textures and colors, allowing for creative architectural designs.
Durability: The materials used in EIFS provide excellent resistance to weather conditions, including moisture and wind.
Lightweight Construction: Compared to traditional stucco or brick, EIFS is lighter, reducing structural load and facilitating easier installation.
Cost-Effectiveness: EIFS can be more affordable than other cladding systems, offering long-term savings through energy efficiency.
Assessing EIFS: Level 1 and Level 2 Evaluations
Regular assessments of EIFS are crucial to ensure their performance and integrity. These evaluations help identify potential issues like water intrusion, which could lead to more significant problems if left unaddressed.
Level 1 Assessment
A Level 1 Assessment involves data gathering and both noninvasive and invasive investigations.
Preliminary Data Gathering
The assessment starts with a thorough review of available documentation from the original construction, including:
Architectural and Structural Drawings
Project Manuals
Product Submittals and Manufacturer Specifications
This information helps establish existing conditions and any potential issues with the EIFS.
Noninvasive Investigation
The noninvasive phase includes a visual survey of the EIFS, focusing on aspects such as:
Surface Finish Consistency: Observing for fading, chalking, and worn spots.
Cracking or Spalling of the Lamina
Exposed Mesh or Foam
Condition of Building Sealants
Inspectors may use ladders or lifts to access different building heights for a comprehensive evaluation.
Invasive Investigation
Invasive methods include moisture testing and evaluating the integrity of underlying substrates. This may involve:
Moisture Probes: Checking for moisture levels in the EIFS and underlying sheathing.
Rigidity Checks: Assessing the rigidity of substrates to detect deterioration.
Selective Demolition: Accessing the back of the EIFS for closer examination.
Level 2 Assessment
A Level 2 Assessment is recommended when a more in-depth evaluation is necessary. It includes methods like infrared thermography and field pull tests.
Infrared Thermography
This non-destructive method identifies thermal anomalies that may indicate trapped moisture or energy loss. The results require careful interpretation and follow-up with moisture probing or selective demolition to verify findings.
Field Pull Test
The field pull test assesses the installation adequacy and wind load capacity of the EIFS system. It involves cutting into the wall, adhering a test board, and pulling it to measure the EIFS's resistance to wind loads. This test provides valuable data on the overall condition and anticipated performance of the EIFS.