Updated September 22, 2025
Flame spread ratings show how quickly fire moves across a material’s surface and how much smoke it produces, as measured by ASTM E84. Materials are rated Class A (best, FSI 0–25), B, or C. For fire endurance over time, ASTM E119 measures how long an assembly can resist fire exposure.
When selecting materials for occupied renovations or construction projects, understanding fire safety ratings is essential. While traditional methods for containing dust and debris often fall short, high-quality reusable temporary wall systems are engineered to meet the strictest standards. Knowing the difference between flame spread ratings (ASTM E84) and fire endurance ratings (ASTM E119) helps Facilities Managers and Project Managers make informed, compliant choices that protect occupants and support long-term project goals.
What are Flame Spread Ratings?
The ASTM E84 test is the industry standard for assessing the flame spread and smoke development of building materials. During this test, a sample is exposed to fire in a controlled chamber to measure how quickly flames move across its surface (Flame Spread Index, or FSI) and how much smoke it generates (Smoke Developed Index, or SDI).
Results are grouped into three categories required by the International Building Code (IBC) and the National Fire Protection Association (NFPA):
- Class A: FSI 0–25 (best performance, lowest spread).
- Class B: FSI 26–75.
- Class C: FSI 76–200.
In healthcare and other highly sensitive environments, Class A is almost always required, ensuring maximum protection.
ASTM E84 vs. ASTM E119: Key Differences
It’s easy to confuse flame spread and fire endurance. While ASTM E84 measures how fast flames and smoke spread across the surface of a material, ASTM E119 evaluates how long a wall assembly can withstand fire exposure before failing structurally.
- E84 = speed of surface flame and smoke spread.
- E119 = endurance of the whole wall system over time.
Both standards play critical roles in life safety, but they answer different questions. For Facilities Managers and Project Managers, this distinction is vital when specifying materials that must both resist flame spread and provide extended fire protection.
Temporary Construction Walls with a Class A Rating
STARC’s RealWall™, LiteBarrier™, and FireblockWall™ temporary wall systems have all been tested to meet the strictest ASTM E84 Class A performance requirements. These solutions deliver the lowest flame spread and smoke development ratings, ensuring that occupied spaces remain as safe as possible during renovation or construction.
Beyond flame spread, these modular wall systems are engineered for:
- Airtight seals for dust and debris control.
- Quick installation and reconfiguration.
- Professional aesthetics that blend with permanent surroundings.
What about StackBarrier?
StackBarrier™ panels are ASTM E84 rated to Class C, with a Class A option available. While not intended for healthcare environments that require Class A by default, StackBarrier is an excellent choice for airports, lobbies, atriums, and high-bay projects that demand tall, flexible containment (up to 40′).
The First and Only Reusable One-Hour Fire-Rated Wall System
While E84 addresses flame and smoke spread, many projects also require a one-hour fire-rated barrier. STARC’s FireblockWall is the first—and only—reusable one-hour fire-rated temporary wall system on the market. Tested to ASTM E119 standards, FireblockWall helps contractors meet NFPA 241, local building codes, and Interim Life Safety Measures (ILSM) requirements.
FireblockWall offers:
- Compliance with multiple fire and life safety codes.
- Rapid deployment (up to 4x faster than fire-rated drywall).
- Negative air and pressure monitoring panel options for healthcare and lab environments.
- Rugged construction for repeated use across multiple projects.
This combination of safety and efficiency makes FireblockWall a breakthrough for healthcare renovations, life science facilities, and any environment requiring stringent fire protection.
Beyond Fire Ratings: Comprehensive Project Safety
Fire safety is just one piece of the puzzle. STARC’s modular wall systems also deliver:
- Noise Reduction: RealWall reduces renovation noise by up to 50%.
- Durability: Fiberglass-reinforced polymer panels resist dents, scratches, and impacts.
- Cleanability: Gloss-white aluminum and FRP surfaces are easy to disinfect.
- Sustainability: Reusable for hundreds of projects, with up to 95% recyclability by weight.
- ICRA Compliance: Meets or exceeds Class IV/V requirements to protect vulnerable patients and staff.
For Project Managers and Facilities leaders, this means safer, cleaner, and more cost-effective solutions compared to single-use drywall or polycarbonate panels.
FAQs About Flame Spread Ratings and Temporary Walls
ASTM E84 measures how quickly flames and smoke spread across a material’s surface. ASTM E119 measures how long a complete wall assembly can resist fire before failure. Both are important for different aspects of fire safety.
Yes. RealWall™, LiteBarrier™, and FireblockWall™ all meet the stringent ASTM E84 Class A standard, providing maximum protection against flame spread and smoke development.
Yes. FireblockWall™ is the only reusable one-hour fire-rated temporary wall system, tested to ASTM E119 standards and compliant with NFPA 241.
Because vulnerable patients and critical equipment are at higher risk, healthcare projects almost always require Class A materials (FSI 0–25) to minimize flame spread and smoke.
Not all. RealWall™, LiteBarrier™, and FireblockWall™ are Class A rated under ASTM E84. StackBarrier™, designed for tall containment up to 40’, is rated Class C with a Class A option available, making it ideal for airports, lobbies, atriums, and high-bay projects.
Takeaway: Safer Fire Protection for Sensitive Environments
Understanding the difference between flame spread and fire endurance helps ensure compliance and occupant safety. With Class A ratings across its systems and the only reusable one-hour fire-rated option available, STARC provides Facilities Managers and Project Managers with peace of mind—and a smarter way to meet today’s fire and safety standards.
Ready to protect your next project with code-compliant temporary walls? Talk to our team today to learn more about STARC’s RealWall, LiteBarrier, FireblockWall, and StackBarrier systems.