Daily Code Talk #61: IMC 506 Part 4 (506.3.13 Exhaust Outlet Terminations)

🧠 Plain-English Highlights• 506.3.13 exhaust outlets: Grease duct exhaust outlets must meet the termination rules in 506.3.13.1 through 506.3.13.3.• 506.3.13.1 above-roof terminations: If you terminate above the roof, the discharge opening must be at least 40 in above the roof surface.• 506.3.13.2 through-wall terminations: Wall terminations are allowed only when the discharge will not create a public nuisance or fire hazard.Also: – You cannot terminate where the IBC requires protected openings. – Keep it at least 3 ft from any opening in the exterior wall. – Still must meet the separation rules in 506.3.13.3.• 506.3.13.3 separation distances: Unless you qualify for the exception, locate the exhaust outlet:– At least 10 ft horizontally from parts of the same/contiguous building, adjacent buildings, and adjacent property lines.– And at least 10 ft above adjoining grade.– Also: at least 10 ft horizontally from, OR at least 3 ft above, outside air intakes into any building.Exception: You can reduce the 10 ft horizontal separation to 5 ft (from buildings, property lines, and air intakes) when the exhaust discharges away from those locations.🏗️ Why it mattersCommon redlines: “mystery” wall terminations near windows, terminations too close to OA intakes, and roof fans too low above roofline. These become real issues fast: grease staining, and odor complaints.🗺️ Where to show it• Roof plan: dimension from exhaust outlet to OA intakes, roof edges/property lines (as applicable), and note “40 IN MIN ABOVE ROOF.”• Exterior elevations: call out wall termination distances to nearby openings and the discharge direction (especially if using the 5 ft exception).• Mechanical schedules/notes: identify “ABOVE ROOF” vs “THRU WALL” and reference IMC 506.3.13.✅ Do• Dimension the termination clearances on the drawings (don’t make the AHJ guess).• Call out discharge direction when you’re relying on the 5 ft exception.⛔ Don’t• Don’t place a grease duct outlet near OA intakes, operable windows, or property lines without checking the separation rules.• Don’t assume a wall termination is acceptable on tight sites unless nuisance/fire risk and IBC opening protection are addressed.🔧 Field tipOn your roof plan template, add a “GREASE EXHAUST TERMINATION CHECK” note next to each outlet:40 IN ABOVE ROOF (Y/N) + DIST TO OA INTAKE + DIST TO PROPERTY LINE/ADJ BUILDING + DISCHARGE DIRECTION (IF USING 5 FT EXCEPTION).It turns terminations into a quick, defensible plan-review item.Comment “IMC506-P4” if you want a paste-ready roof plan note and dimensioning checklist.