Fire-Rated Assemblies: Selecting the Right Steel Keel and Gypsum Board Combo

Building a Fire-Rated Assembly—be it a wall or ceiling system—is much more than just using fire-resistant components. It requires the precise combination of Steel Keel Framing, Fire-Resistant Gypsum Board, and meticulous installation that adheres strictly to certified standards. This ensures the system can withstand the spread of fire for a specified duration (e.g., 1 hour, 2 hours, or 4 hours).

1. The Foundation: Understanding Fire Rating

A Fire Rating is the time classification given to a structural element (wall, floor, ceiling) detailing its ability to maintain its integrity and prevent the transmission of fire, heat, and smoke over a specific period (e.g., 60 minutes, 120 minutes). These ratings are based on international testing standards like ASTM E119 or BS 476 Part 20 & 22.

Crucially, the Fire Rating is awarded to the entire system, meaning all components must work together exactly as tested.

2. Selecting Fire-Resistant Gypsum Board

Fire-resistant gypsum boards are engineered with a more resilient gypsum core than standard boards, often reinforced with fiberglass and special additives. These reinforcements allow the board to maintain its structural integrity for an extended period under high heat.

Key Tip: For longer fire ratings (e.g., 2 hours instead of 1 hour), the assembly often requires two layers of fire-resistant gypsum board on each side of the framing.

3. Selecting the Right Steel Keel Framing System

The steel framing used in a fire-rated system must be galvanized steel of a specified thickness, which may differ from standard commercial framing. The critical factors are thickness (Gauge) and the fixing methodology used in the tested assembly.

• Track and Studs (U-Track / C-Stud): The gauge, dimensions, and spacing (400mm or 600mm centers) must match the certified system's specifications.

• Structural Integrity: The studs must be robust enough to withstand heat distortion and continue supporting the gypsum board layers once they soften under intense heat.

**Caution:** Using an uncertified or incorrect gauge of steel keel framing can lead to premature failure of the wall assembly during a fire, even if the correct fire-rated gypsum board is used.

4. Essential Supporting Components

Small components can significantly impact the assembly's overall fire performance:

• Insulation: The inclusion of fire-resistant insulation, such as Mineral Wool or certified fiberglass batt, within the wall cavity is often mandatory.

• Screws: The specific screw type (length and diameter) is critical. They must be strong enough to hold the multiple layers of board securely to the frame throughout the fire test duration.

• Firestop Sealants: All joints and gaps must be sealed using certified Firestop Sealants to prevent the passage of flame and smoke.

 Contact Us for Certified Fire-Rated Assemblies

Installing a fire-rated system demands precision and adherence to the highest safety standards. If you are designing a project that requires a specific Fire Rating or need guidance on selecting the correct combination of steel keel and gypsum board for compliance:

Please Contact Us Today. Our experts can provide technical data, specific product combinations that hold valid fire test reports, and ensure your system meets all required building codes and engineering specifications.