Mineral wool is preferred over fiberglass in which scenario?

• A. Areas with high fire risk or near heat sources
• B. Where cost is the primary concern
• C. Where maximum light reflectance is needed
• D. In dry climates only

Answer: (A)

When fire performance and heat exposure are the main concerns, mineral wool stands out because it resists high temperatures much better than fiberglass. Made from molten rock and slag, mineral wool is noncombustible and retains its structure and insulating ability under very hot conditions, making it a stronger fire barrier around heat sources like furnaces, boilers, and fireplaces. This helps slow fire growth and maintain insulation during a fire, which is why it’s preferred in high fire risk areas.

Fiberglass, while a good insulator and also noncombustible, doesn’t tolerate heat as well as mineral wool in extreme conditions, especially where heat sources are nearby. That’s why the mineral wool choice is favored in settings with significant fire risk or near intense heat.