When specifying architectural coatings, durability expectations often begin with one question: “Which AAMA standard does this coating meet?” Whether the finish is liquid or powder, the architectural industry relies on the same AAMA performance specifications to evaluate exterior coating durability.

While these specifications are now maintained by FGIA (the Fenestration and Glazing Industry Alliance), they are still commonly referred to throughout the industry as “AAMA specs” because of their long-established recognition and use.

For architects, specifiers, and fabricators, understanding the weathering requirements behind AAMA 2603, 2604, and 2605 is essential when selecting the appropriate coating system for a project.

AAMA Standards and Exterior Performance
The American Architectural Manufacturers Association (AAMA) standards establish performance requirements for coatings used on architectural aluminum extrusions and panels. While these specifications evaluate many properties including adhesion, impact resistance, humidity resistance, and chemical resistance, weathering performance is one of the primary differentiators between the three standards.

The AAMA specs outline ASTM test methods and performance requirements, including Florida weathering exposure testing. Because of Florida’s intense UV exposure, humidity, and salty air creating one of the harshest natural weathering environments in North America, successful Florida-exposure testing demonstrates strong long-term durability.

Each specification requires coatings to undergo accelerated and long-term outdoor exposure testing to evaluate how well the finish maintains color and gloss over time. Each performance level addresses weathering effects like checking (fine cracks in the coating surface) and crazing (network of fine cracks in the coating surface), along with color and gloss fading.

AAMA 2603: Interior-Level Durability
AAMA 2603 is typically used for interior architectural applications where long-term weathering durability is less critical. IFS300SP is formulated to meet and exceed AAMA 2603 requirements.

The specification requires:
• 1 year of Florida exposure testing
• No checking, crazing, or loss of adhesion after taping
• Only "slight" color change and chalking after 1 year of exposure

For this reason, coatings meeting AAMA 2603 are generally recommended for good general interior performance on metal substrates but are not intended for highly demanding environments or projects requiring long-term weathering durability.

AAMA 2604: Enhanced Weatherability
AAMA 2604 significantly increases weathering expectations and is commonly specified for exterior commercial architectural applications. It has also become somewhat of a transitionary grade between interior and exterior applications, due to the coatings’ excellent value for money.

Requirements include:
• 5 years of Florida exposure testing
• Minimum 30% gloss retention after exposure
• Stricter color retention standards - no more than 5 delta E color change
• Improved chalk and erosion resistance

IFS400SD is formulated to meet and exceed AAMA 2604 requirements while also supporting sustainability initiatives through reduced VOC emissions and material efficiency. It also comes with a 10-year warranty* to hold to these same performance levels, and a manufacturers EPD.

AAMA 2605: Superior Architectural Performance (superior is the recognized industry term.)

AAMA 2605 represents the industry’s highest level of exterior coating performance for architectural projects. IFS500FP is formulated to meet and exceed AAMA 2605 requirements.

The standard requires:
• 10 years of Florida exposure testing
• Minimum 50% gloss retention
• Very tight color retention limits - no more than 5 delta E color change
• Superior resistance to fading, chalking, and film degradation

These coatings are commonly selected for curtainwall systems, windows, louvers, sun screen systems in a wide variety of projects where long-term exterior appearance retention is critical. To achieve this level of durability, coatings typically utilize advanced resin technologies such as FEVE or PVDF fluoropolymers in powder and liquid formulations. IFS 500FP is a FEVE powder technology that also comes with a manufacturers EPD. A 20-year warranty is available with IFS 500FP products*.

Powder and Liquid Coatings: Same Standards, Different Technologies
One common misconception is that the AAMA standards are only for liquid coatings. This is not the case – they apply equally to both performance powder and performance liquid coatings. Both technologies are evaluated against the same AAMA performance criteria.

The difference between powder and liquid lies not in the specification itself, but in the chemistry and formulation used to achieve compliance. Advances in architectural powder coating technology continue to expand the range of powder systems capable of meeting demanding AAMA 2604 and 2605 requirements while offering the environmental and functional advantages powder coatings are known for.

For architects and specifiers alike, understanding the differences between AAMA 2603, 2604, and 2605 will help to ensure the selected coating aligns with the project’s performance expectations, environmental conditions, and long-term design goals.

*When applied by a Registered Applicator to Architectural Aluminum.