Boilers must be mounted on floors of what type of construction unless otherwise listed?

Boilers must be installed on floors of noncombustible construction unless they are specifically listed for use on combustible floors. This requirement is rooted in safety regulations aimed at minimizing fire hazards associated with boiler operations. Noncombustible materials, such as concrete or steel, do not ignite or propagate fire, thus providing a safer environment for boiler installation.

In contrast, combustible materials such as wood or other easily ignitable substances could pose serious fire risks if there is a failure or leak in the boiler system. The code recognizes that certain applications may allow for boilers to be listed for use on combustible floors, but those scenarios must come with specific safety assurances and product certifications. This ensures that all installations adhere to best practices for fire safety, protecting both the structure and its occupants. Ensuring the proper mounting of boilers on noncombustible surfaces is crucial for maintaining compliance with safety standards and preventing potential hazards.