How far from combustible material must grease laden exhaust duct be kept according to code?

The requirement for maintaining a certain distance between grease-laden exhaust ducts and combustible materials is critical for fire safety. The correct distance is 18 inches, as specified by various building and fire codes, including the National Fire Protection Association (NFPA) standards. This guideline is established to prevent potential ignition of any combustible materials that could be near the ductwork, as grease is a highly flammable substance.

The 18-inch separation ensures that if any heat is emitted from the duct or if grease were to drip, it would not come into direct contact with flammable materials, significantly reducing the risk of a fire starting. This distance is deemed sufficient to create a safety buffer, considering the typical scenarios where grease can collect and pose a fire hazard.

Other options suggest distances that do not adequately provide this level of protection. Distances less than 18 inches may not account for potential heat fluctuations and the accumulation of grease in the duct crevices, leading to increased fire risk. Thus, adhering to the 18-inch separation guideline is a crucial safety measure in the installation and maintenance of grease-laden exhaust systems.