It’s simple, restaurant grease and oil can damage your roof and create an unnecessary fire hazard. Exhaust fans are designed to remove grease vapors from your kitchen. Unfortunately much of this grease will eventually leak onto your roof. Because food grease is acidic it can cause the surface of your roof to deteriorate.
The best way to prevent grease from damaging your roof is to install rooftop grease containment on all your exhaust fans. Properly designed rooftop grease containment will collect and hold the excess grease from your system while allowing rain water to drain off. An effective rooftop grease containment system will include “hydrophobic” pads designed to shed water but hold onto the grease. Just having a grease box to catch the excess grease from your fan without these pads means the rain water and your grease will spill onto the roof.