On what type of construction must boilers be mounted?

Boilers must be mounted on noncombustible construction to ensure safety and compliance with building codes. Noncombustible materials do not ignite or support combustion, which significantly reduces the risk of fire hazards associated with the operation of a boiler. This is crucial in protecting both the structure housing the boiler and adjacent areas from potential fires that may arise from improper installation or maintenance of the boiler system.

Using noncombustible construction materials helps to limit the spread of heat and prevents any accidental ignition of flammable materials that may be present in the vicinity. This is particularly important because boilers operate at high temperatures, and any failure or malfunction could lead to the release of heat that could ignite combustible materials.

Considering the other options, flammable and combustible materials pose significant risks when exposed to the heat generated by boilers, and wooden construction is generally too risky due to the inherent flammability of wood. As a result, noncombustible construction is mandated to enhance the safety and reliability of boiler installations.