Grease Leaking From Duct Seams: What It Means for Your Commercial Kitchen Exhaust System
Your commercial kitchen exhaust system is designed to safely remove heat, smoke, grease-laden vapors, and cooking byproducts from the cooking area. While most kitchen managers regularly see the hood canopy and grease filters, much of the exhaust system is hidden inside ductwork that carries cooking vapors to the rooftop exhaust fan.
One warning sign that should never be overlooked is grease leaking from duct seams. Grease appearing on the outside of ductwork often suggests that grease has accumulated inside the exhaust system or that maintenance is needed. Although small grease stains may seem insignificant, they can indicate larger issues hidden within the ductwork.
Routine inspections and professional hood cleaning help identify grease buildup before it affects the safety and performance of your commercial kitchen.
Why It Matters
As grease-laden vapors travel through the exhaust ductwork, a small amount of grease naturally collects on the interior walls of the ducts. Over time, this accumulation can become excessive if the exhaust system is not cleaned according to an appropriate maintenance schedule.
When grease builds up inside the ductwork, it may begin to seep through seams, joints, or connections.
Grease leaking from duct seams can:
- Increase the amount of combustible grease within the exhaust system.
- Stain ceilings, walls, or equipment.
- Create slippery surfaces if grease drips onto floors.
- Produce unpleasant odors.
- Indicate that the exhaust system may require professional cleaning.
- Lead to additional maintenance concerns if left unaddressed.
Addressing grease leaks early can help prevent more extensive cleaning and repairs later.
What Inspectors Look For
During a commercial kitchen inspection, fire inspectors often examine accessible portions of the exhaust system.
They may observe:
- Grease stains around duct seams.
- Grease dripping from duct joints.
- Excessive grease accumulation near access panels.
- Grease residue on ceilings or surrounding surfaces.
- Missing or damaged duct access panels.
- Evidence that routine maintenance has been neglected.
Visible grease on the outside of ductwork often prompts inspectors to evaluate the overall condition of the exhaust system more closely.
How To Check It Yourself
Kitchen managers should periodically inspect exposed sections of ductwork.
Look for:
- Brown or yellow grease stains.
- Grease dripping from seams or joints.
- Sticky residue on duct surfaces.
- Grease collecting around access doors.
- Unusual grease odors.
- Ceiling stains near ductwork.
If grease is visible on the exterior of the ductwork, additional grease may also be present inside the system.
How To Correct It
Simply wiping grease from the outside of the ducts will not solve the underlying problem if grease has accumulated inside the exhaust system.
To help reduce grease leaks:
- Schedule routine professional hood cleaning.
- Keep grease filters clean and properly installed.
- Maintain access panels for inspection.
- Monitor high-volume cooking operations.
- Address grease buildup before it becomes excessive.
- Maintain accurate hood cleaning service records.
Professional hood cleaning removes grease throughout the hood, ductwork, filters, and rooftop exhaust fan.
When To Call A Professional
You should contact a professional hood cleaning company if:
- Grease is leaking from duct seams.
- You notice grease stains on ceilings or walls.
- Smoke is lingering in the kitchen.
- Cooking odors have increased.
- It has been several months since the last hood cleaning.
- You’re preparing for a fire or insurance inspection.
- You are unsure whether grease has accumulated inside the ductwork.
A qualified hood cleaning company can inspect your entire exhaust system and recommend the appropriate cleaning schedule for your cooking operation.
Related Articles
Continue learning about commercial kitchen fire safety:
- Grease Accumulation Inside Ducts
- Grease Buildup Behind Filters
- Grease Dripping From Hood Seams
- Missing Access Panels
- Corrosion or Damaged Hood Components
- Rooftop Exhaust Fan Grease Buildup
- Understanding NFPA 96 Hood Cleaning Guidelines
- Top 50 Commercial Kitchen Fire Safety Issues That Can Lead to Inspection Violations
Schedule Service
Grease leaking from duct seams is often more than a cosmetic issue. It can be an indication that grease has accumulated inside your commercial kitchen exhaust system and that professional cleaning is needed.
All City Hood Cleaning proudly provides professional commercial kitchen hood cleaning services throughout Wisconsin for restaurants, schools, hospitals, nursing homes, hotels, breweries, food trucks, casinos, churches, manufacturing facilities, and many other commercial kitchens.
Our experienced technicians clean the entire kitchen exhaust system, including the hood, filters, ductwork, and rooftop exhaust fan, helping businesses reduce grease buildup, improve ventilation, and stay prepared for inspections.
Contact All City Hood Cleaning today at 414-405-8500 for a free estimate and let us help keep your commercial kitchen exhaust system clean, safe, and operating at its best.