What is the correct orientation for installing mineral wool?

The correct orientation for installing mineral wool is such that the fibers are running horizontally. This orientation helps to effectively block the passage of fire, smoke, and heat, enhancing the firestop performance. Horizontal installation allows for the proper fit within wall and ceiling assemblies, ensuring that the mineral wool adheres well to the surrounding materials and minimizes air gaps, which could otherwise compromise the integrity of the firestop system.

When fibers are oriented horizontally, they also provide better support and compression when installed in static applications. This is particularly important in creating a tight seal around penetrations and joints, which are critical areas in firestop systems. Proper fiber orientation is essential for achieving optimal thermal and acoustic performance characteristics of mineral wool, as this material is designed to function effectively in passive fire protection systems.