Rooftop Grease Containment in Bradford
Bradford Hood Cleaning Pros is the contractor for the end of the grease path, where a kitchen exhaust fan discharges at roof level. Rooftop grease containment keeps that discharge from spreading across the roof, running down a parapet or reaching a storm drain. The fan, the blower wheel, the curb and the roof around the discharge are cleaned on the same visit as the hood, any containment already fitted is checked, and the result is photographed. From $385 per visit.
Rooftop grease is a landlord problem before it is a fire problem
Grease discharged at the fan lands on roofing the tenant does not own, which is why the question usually arrives from a property manager rather than from a chef.
The exhaust fan sits on a curb and grease-laden vapour leaves through it. Some condenses at the housing and drains back down the curb. The rest settles on the roof downwind of the discharge, and on a busy fry or char line the affected area grows season by season until the surface around the curb reads dark and tacky.
Two things then cost money. Grease attacks the roof covering, and grease travels. A single-ply membrane with its adhesives and welded seams was never specified to sit under a petroleum-adjacent contaminant for years. And a roof drains somewhere, so what the roof carries goes into the building storm system, which is the side of the building that was never meant to see kitchen grease at all.
What rooftop grease does to a TPO or EPDM membrane and to the warranty
Grease softens and degrades single-ply membrane over time, and most roofing warranties exclude damage from a contaminant the building allowed to sit on the roof.
Flat commercial roofs across Bradford, Newmarket and Aurora are mostly single-ply. TPO is the light-coloured thermoplastic sheet welded at the seams. EPDM is the black rubber sheet bonded at the laps. Both are engineered for weather, foot traffic during service work, and ultraviolet exposure. Neither is engineered as a grease tray.
Sustained contact matters more than a spill. Standing grease keeps a surface permanently wetted, holds grit against it, and works into seams and flashing details where the sheet is bonded rather than continuous. Those details are where a roof fails first under any condition, and grease gives them a head start. On the newer plazas along Highway 400 and Davis Drive, where the membrane may still be under warranty, that is not a theoretical concern.
The warranty consequence is the part that surprises owners. A roofing warranty covers the roof performing as installed. It does not usually cover exposure to something outside its specification, and a documented pattern of exhaust grease around a fan curb is a straightforward exclusion for a manufacturer to point at. The result is a roof that fails early with no coverage behind it, on a building where the operator downstairs assumed hood cleaning was the whole obligation.
Containment options compared, and the one failure mode they share
Containment approaches differ in how much grease they hold and how often the media has to be changed, and every fitted option fails the same way when nobody maintains it.
| Approach | What it actually does | Media change | Where it suits a local roof |
|---|---|---|---|
| Nothing fitted | Grease discharges straight onto the membrane and spreads with weather and slope. | None, and the roof absorbs the cost instead. | Only defensible on a light-volume kitchen with a ballasted roof and a documented cleaning interval. |
| Absorbent filter box at the curb | A shallow tray of absorbent media catches drainage from the housing before it reaches the roof. | Media saturates and must be changed on a set interval. Once saturated it stops working entirely. | The common fit on a converted Holland Street storefront where the riser is short and the roof sits tight to the fan. |
| Catch basin or grease box | A larger reservoir collects liquid grease rather than absorbing it, so volume is visible and can be drawn off. | Emptied rather than replaced, but it overflows if nobody checks it. | Heavy fry and char lines, and Holland Marsh food operations where the fan runs long hours through the season. |
| Full containment tray under the fan | A tray sized to the curb footprint holds media across the whole discharge area, not just the drain point. | Highest media consumption, and the change has to be logged to be worth anything. | New membrane roofs still under warranty, and multi-tenant plazas with a shared roof drain. |
The failure mode is identical across all three fitted options: containment gets installed once and then forgotten. Saturated media is not containment. It is a soaked object sitting on the roof that everyone believes is solving the problem. Whatever is fitted, the media interval has to be tied to the cleaning schedule so one visit handles both.
Where roof access decides the visit in Bradford and York Region
Access sets the shape and duration of a rooftop visit before any cleaning happens, and it varies sharply between an old main street building and a newer plaza.
On Holland Street and Barrie Street in Bradford, and in the older cores of Newmarket and Aurora, a roof-mounted fan is usually reached by ladder from a rear lane rather than by an interior stair. That changes the safety setup and the time on site, and it means weather can move a booking. On the newer plazas out toward Highway 400, Davis Drive and Green Lane there is generally proper roof access, and the constraint shifts to keys, escort and after-hours entry rules instead.
Either way the work runs overnight or between service hours so the kitchen does not lose a shift. Grease removed at the fan is collected and taken away rather than washed across the roof, which is the shortcut that turns a fan problem into a drain problem.
Every visit ends with before-and-after photographs of the fan, the curb and the roof area, plus the signed certificate referencing the published NFPA 96 standard. For a property manager the photographs are the useful part, because they are dated evidence that the fan curb was clean on a known date. Proof of WSIB and liability coverage is supplied before anyone goes on the roof. The work upstream is on the kitchen exhaust cleaning page, and access to the fan itself is on the hinge kit page.
Rooftop grease containment: frequently asked questions
What building owners and property managers ask about grease at roof level.
Does hood cleaning include the roof and the fan?
Bradford Hood Cleaning Pros includes the rooftop exhaust fan in the standard scope, along with the curb and the roof area immediately around the discharge point. A visit that stops at the canopy leaves the part of the system actually discharging onto the roof untouched, and it also leaves the compliance question open, since the NFPA 96 grease limit applies to any surface in the exhaust path.
Can rooftop grease void a roof warranty?
Roofing warranties generally cover the roof performing as installed and exclude damage from contaminants the roof was never specified to carry. Exhaust grease sitting on a TPO or EPDM membrane is a visible, documentable condition, which makes it a straightforward exclusion for a manufacturer to point at. The defence is maintained containment plus dated photographs showing the fan curb clean on a known schedule.
How often does containment media need changing?
Before it saturates, and how fast that happens depends on cooking volume rather than on the calendar. A heavy fry or char line loads media far faster than a low-volume kitchen. The practical approach is to tie the media change to the cleaning visit so one contractor handles both, then adjust the interval based on what the media looks like each time.
Who pays for rooftop grease cleanup, the tenant or the landlord?
That depends on the lease, and it is a common source of disputes because the exhaust system usually sits with the tenant while the roof sits with the landlord. Grease crosses that line. The cleanest arrangement is for the rooftop portion to be part of the same scheduled exhaust cleaning contract, so it gets done and photographed on a known interval instead of being argued about after a roof inspection.
What if grease has already reached the storm drain?
Then the priority is stopping the source before dealing with what is downstream, because a cleaned drain refills from a dirty roof. Rain events are what make this visible: a dry stretch lets grease build up around the discharge zone, then the first heavy rain moves the accumulation to the low point in one go. That is why the discovery is usually a slug of grease at a downstream point rather than a gradual complaint.