Grease Duct Fabrication

Grease exhaust ductwork is one of the most safety-critical components in any commercial kitchen ventilation system. At Metal Men Mechanical, we fabricate grease duct that meets the stringent requirements of NFPA 96 (Standard for Ventilation Control and Fire Protection of Commercial Cooking Operations), the International Mechanical Code, and New York City fire code.

Every grease duct section fabricated in our Brooklyn shop features continuously welded seams and liquid-tight construction to prevent grease leakage and contain fire within the duct system. We understand that the safety of your building and your client's business depends on the quality of this ductwork, and we build accordingly.

NFPA 96 requires that grease exhaust ductwork be constructed with continuous liquid-tight welds. This means every longitudinal seam and transverse joint must be fully welded — no drive cleats, no S-clips, and no sealant-only connections. Our welders are trained specifically in grease duct fabrication techniques that meet these requirements.

We fabricate grease duct from a minimum of 16-gauge carbon steel (black iron) or 18-gauge stainless steel, in accordance with NFPA 96 gauge requirements based on duct size. All joints are welded from the exterior of the duct to create a smooth interior surface that minimizes grease buildup and facilitates cleaning.

NYC building code requires specific clearances between grease ductwork and combustible construction. We fabricate grease duct systems that account for the required 18-inch clearance to combustibles, or reduced clearances when approved listed enclosure systems are specified.

Our grease duct fabrication includes all system components: straight sections, elbows, transitions, cleanout access panels, and connections to grease exhaust fans and kitchen hoods. We coordinate with contractors on routing and clearance requirements during the estimating phase to identify potential conflicts before fabrication begins.

Grease duct systems in New York City are subject to FDNY inspection. Our fabrication meets all requirements that inspectors look for, including proper weld quality, correct material gauge, liquid-tight construction, and appropriate access panel locations for system cleaning.

We provide material certifications and fabrication documentation to support your permit applications and inspections. When your grease duct carries our label, inspectors know the fabrication meets code requirements.

We fabricate grease duct for every type of commercial kitchen operation in New York City. From full-service restaurants and fast-food locations to institutional kitchens in hospitals, schools, and corporate cafeterias, our grease duct systems protect buildings and occupants from the fire hazards associated with commercial cooking.

For restaurant buildouts in dense NYC neighborhoods, we understand the challenges of routing grease duct through tight shaft spaces and across occupied floors to reach roof-mounted exhaust fans. We work with contractors to optimize duct routing and minimize the number of elbows and transitions, improving system performance and reducing installation complexity.