Rockwool Insulation: Fire Ratings, Properties, and Applications

Rockwool insulation, also known as mineral wool or stone wool, is one of the most fire-resistant types of insulation materials available. With a class A or Class 1 fire rating as per ASTM E84, Rockwool offers an exceptional level of fire protection. This article delves into the fire ratings of Rockwool insulation, its properties, and its applications in various settings.

Fire Rating of Rockwool Insulation

Rockwool insulation typically has a fire rating of Class A or Class 1 according to ASTM E84. This certification means it has a flame spread index of 0-25 and a smoke developed index of 0-450. These specifications indicate that Rockwool is highly resistant to fire, making it suitable for applications where fire safety is critical.

Rockwool is known for its high-temperature resistance, with a melting point around 1400 to 1500 degrees Celsius (2552 to 2732 degrees Fahrenheit). This high melting point makes Rockwool ideal for use in commercial buildings, industrial settings, and areas requiring fire-rated assemblies. It is important to refer to the specific product data sheet for detailed fire performance information, as ratings can vary slightly by product or manufacturer.

Properties and Composition of Rockwool

Rockwool is made from extruded mineral fibres of molten rock. The fibres are bound together with a phenolic-based organic binder, which is a key component in terms of fire resistance. The amount of this binder is less than 2%, which means the finished product can be classified as non-combustible according to standardized fire tests.

Despite the binder's resistance to fire, the material used to store Rockwool, such as polyethylene sleeves, is combustible. However, the percentage of this material is low enough to prevent rapid fire spread when stored in warehouses. Manual fire-fighting is sufficient, and automatic fire suppression for Rockwool warehouses is not required, provided the warehouse itself is non-combustible.

Fire-Resistant Products and Applications

Roxul, a leading manufacturer of Rockwool insulation, has developed specific products with enhanced fire resistance ratings. For example, Roxul Safe 65 55 offers a one-hour fire resistance rating, while Roxul SafeTM 55 provides a two-hour fire resistance rating from the interior side. These products allow builders to reduce the required separation distances and increase the area of buildings in close proximity to each other.

These fire-resistant ratings are beneficial in various applications, such as:

Commercial buildings Industrial settings Floors, ceilings, walls, and roofs Fire-resistant assemblies and constructions

The benefits of using Rockwool insulation in these applications include increased safety, compliance with building codes, and reduced risk of fire spread.

Conclusion

In conclusion, Rockwool insulation is a highly fire-resistant material that offers excellent protection against fires. Its Class A or Class 1 fire rating, high melting point, and advanced fire-resistant products make it an ideal choice for critical environments. By understanding the fire ratings and properties of Rockwool, builders and property owners can ensure a safer and more secure environment for occupants and assets.

Keyword: Rockwool, Fire Rating, Insulation