Membranes and Metal That Tolerate Grease
Not every roof sheet takes grease equally well. Some EPDM and TPO membranes swell, soften or lose their seam strength when oils sit on them, while PVC and KEE membranes are formulated for the exposure and are the usual choice over a kitchen. We check the manufacturer's published guidance for the system we install, and where only the area near the fan needs a different sheet, we weld a grease-resistant section into the rest of the roof.
The metal matters as well. The curb under the fan is flashed with a hand-formed counterflashing so no grease can get behind it, and a grease containment tray sits under the fan outlet so the mist falls into a pan rather than onto the roof. We use stainless or coated metal around exhaust outlets because grease and heat eat ordinary galvanized sheet. The finished curb should shed water and hold grease, and a cook or an owner can clean the tray in a few minutes.
Roofing Over a Kitchen That Cannot Close
A restaurant has services to run, and the roof sits directly over the cooks. We start early, before prep, or work in the afternoon lull, and we avoid the lunch and dinner rushes. Air intakes and exhaust outlets are protected so fumes and dust do not reach the kitchen, and where an open flame is a poor fit for a building with a gas line and grease ducts, we choose cold-applied or mechanically attached systems and keep torches off the roof.
The roof is closed in each evening, and the kitchen's schedule decides our start time. For tenants on the ground floor of an older multi-story building, the work happens above the offices and the apartments as well, so we coordinate with the property manager. A retail and restaurant chain with several locations gets a repeatable plan: the same notice, the same protection and the same cleanup at every store, so the second site goes faster than the first.
Brick Blocks, Heat and Fire Rules
Restaurants cluster in the districts people walk through. Old Pasadena has brick-facade storefronts with restaurants at street level and offices above, and Playhouse Village holds more than 45 restaurants, bars and cafes across 32 blocks. Where a building like that has a brick parapet, the exhaust riser that passes through the roof, the parapet cap behind it and the ladder access to both need attention at once. We handle the riser flashing and the parapet together, because the leak is rarely in only one of them.
Heat is part of the job here. With a recorded June high of 113 F, a rooftop condenser and a grease-laden membrane work in a harsh environment, and the roof surface can run well above air temperature. Fire adds a second concern. Grease deposits, hot exhaust and a roof assembly all have to be considered together, and in Very High Fire Hazard Severity Zones a Class A covering is required on new buildings and on any reroof that takes over half the existing roof in a twelve-month span. A kitchen in the Playhouse District and a microbrewery on Lincoln Avenue in northwest Pasadena can carry very different exhaust loads, and we plan each roof for its own.
Cleaning Schedules and Seasonal Checks
A restaurant roof lasts longest when someone looks at it every season. A quick spring check covers the exhaust fan ring, the condenser drain and any membrane that feels soft. A fall visit before the rainy months clears the drains and checks the flashings. Between those, the kitchen's cleaning crew can empty and rinse the grease tray on a regular schedule, and we show them where it is and what to look for.
The same discipline carries into a larger property. A shopping center with several food tenants needs one map of who is on which curb, and a grocery store with a deli faces the same grease problem on a bigger scale. Pasadena is also home to Dine Brands Global, and any restaurant group with several sites knows that one site's roof problem tends to repeat at the next. When we write up what we find, we describe the roof in a form the owner can hand to a landlord or a franchisor.
Commercial Roofing Questions
How can I tell if grease is already damaging my restaurant roof?
Look at the membrane around the exhaust fan. A dark, glossy ring, a surface that feels soft or tacky, blisters near the curb and seams that have started to lift are the signs. Grease can also run to a drain and stain the roof below it. If you see any of these, we should look before the water finds the damaged spot.
Do you need to shut the kitchen down to reroof?
No, in most cases the kitchen keeps running. We protect the exhaust and intake openings, keep the crew away from them during service and close in the roof each evening. If a particular step has to happen over a hot line, we plan it for the quietest hours and talk it through with the chef or manager first.
Why did my roof start leaking after a new walk-in cooler was installed?
A new condenser often brings new curbs, new line sets and new openings, and the refrigeration contractor may not be a roofer. If the penetrations were flashed with sealant alone, they can fail in a season. We inspect the work, rebuild any weak boot and, where needed, add a pan so condensate does not stand on the membrane.
Is TPO a poor choice for a restaurant roof?
Not always, but it needs more thought than PVC or KEE over a kitchen. Some TPO formulations tolerate grease better than others, and the manufacturer's guidance for the exact product matters. We pick the sheet based on what the exhaust puts out, and we often use a different sheet near the fan than on the field.
Who is responsible for the roof when I lease the restaurant space?
The lease controls how roof maintenance and equipment-related repairs are allocated. Dated photos and inspection findings can identify the failed detail and give the property owner and tenant a clear basis for deciding who approves the work.
