What ingredient in firestop products contributes to their fire resistance?

The ingredient in firestop products that contributes significantly to their fire resistance is intumescent materials that expand with heat. When exposed to high temperatures, these materials undergo a chemical reaction that causes them to swell and form a thick, insulating char. This char acts as a barrier, preventing the passage of flames, smoke, and heat through openings and joints in fire-rated walls and floors.

These intumescent properties are essential for maintaining fire compartmentalization, allowing for a more effective firestop solution that can withstand prolonged exposure to fire. The expanded material not only helps in sealing the openings but also contributes to the overall fire resistance rating of a space, ensuring that it can help protect against the spread of fire for a specified duration. Such characteristics are crucial in maintaining building safety standards and are a fundamental aspect of firestop technology.