Is Rock Wool Board Fire Resistant?

Many people do not fully understand the performance of rock wool boards. They often ask whether rock wool boards are fire resistant or flame retardant, and also wonder if they will produce smoke, melt or drip when exposed to fire, and whether their fire resistance will decline over time.

Here is our clear answer: Rock wool board is a Class A non-combustible material and will not burn by itself.

Many people mistakenly believe that fire resistance means the material will not deform under high temperatures, which is a misunderstanding. The key advantage of rock wool board is that it is non-combustible by nature. It cannot be ignited by open flame, will not sustain combustion and will not act as fuel to spread fire.

Rock wool board is made from basalt and diabase. The raw stones are melted at over 1400℃, spun into inorganic mineral fibers and then cured into boards. Its fire resistance comes from its inorganic composition, and no flame retardant additives are required. It has no combustible organic carbon chains and extremely low combustion heat value.

When exposed to open flame, rock wool board will not catch fire, spread flame or drip burning molten droplets. It will only soften slowly under extreme heat and will not release large amounts of toxic smoke. In a fire, it can block heat transfer and slow down the spread of flames.

Some customers ask whether higher density means better fire performance. The answer is no. Density mainly affects the tensile and compressive strength of the board. With qualified raw materials and production process, rock wool boards of different densities can all maintain Class A non-combustible performance.

Haochen Insulation focuses on the production of rock wool boards. Our products feature stable fire resistance. Samples are available for testing. Welcome to contact us for cooperation.