PVC is the only common single ply roofing membrane that resists kitchen exhaust grease, which is why Brooklyn restaurants and bakeries need it. MLM Construction Group is a licensed commercial roofer, HIC #2130570, with 97 Google reviews at 5.0. Call (516) 713-9199.
Every commercial kitchen in Brooklyn pushes animal fats and cooking oils out through a rooftop exhaust fan. Some of that lands back on the roof around the fan, and it keeps landing there every service, every day, for years. On the wrong membrane that is not a housekeeping issue, it is a slow chemical attack.
The reason is simple. Most single ply membranes are held together by plasticizers, the additives that keep the sheet flexible. Animal fats and cooking oils leach those plasticizers out. As they leave, the membrane hardens, shrinks slightly and goes brittle, and then it cracks, usually in a ring around the exhaust fan where the deposit is heaviest. You will see a roof in good condition everywhere except a two or three meter circle that looks completely different.
PVC is formulated to resist exactly this. It is the standard specification for restaurants, bakeries, commissaries, food processing and any building with significant rooftop kitchen exhaust, and it is specified that way because of decades of field evidence rather than marketing.
EPDM is a rubber membrane and it has genuine strengths, but oils and fats are not kind to it. TPO has improved a great deal and it performs well on plenty of Brooklyn buildings, but grease resistance is not what it is built for. If the building has a kitchen, specifying by price alone and ending up with the wrong sheet around the exhaust is one of the more expensive mistakes available in commercial roofing, because the failure is concentrated exactly where the penetrations are.
PVC also welds. The seams are hot air welded into a single continuous sheet rather than relying on adhesive or tape, which matters on a roof with a lot of curbs, ducts and penetrations, and a Brooklyn restaurant roof always has a lot of penetrations.
It is highly fire resistant, which is worth something on a building where the floor below contains open flame. It is reflective, so it does not drive summer cooling costs the way a dark roof does, and on a Brooklyn flat roof in July that is a real number. It handles ponding better than most, which matters because so many older Brooklyn flat roofs have settled and hold water.
And the detailing around a curb is straightforward. Every piece of rooftop equipment on a restaurant is a potential leak, and a membrane that can be welded tight to a formed corner is worth more on that roof than on a clean open warehouse deck.
Walk out to the exhaust fan and look at the membrane in the circle around it, then compare it with the membrane twenty feet away. You are looking for a difference. Discoloration, a surface that has gone hard or chalky, a slight shrinkage pulling the sheet away from a curb, and cracking that follows the shape of the deposit rather than the shape of the roof.
Check the grease containment on the fan itself. Most commercial kitchens are supposed to have a filter or a containment system at the exhaust, and a surprising number either never had one or have one that nobody has emptied. Fixing that stops the problem getting worse while you plan the roof.
Then check the seams and the curb flashing nearest the fan, because that is where a hardened membrane lets go first.
You do not always have to replace the whole roof. If the rest of the membrane is sound and the damage is confined to the area around the exhaust, a compatible section can sometimes be cut out and replaced, with the new material carried well past the edge of the affected zone.
Whether that is the right answer depends on what the existing membrane is, how old it is, and whether the two materials are compatible at the seam, which not all of them are. We will tell you honestly whether a section replacement is buying you years or months, and price both options so the decision is yours with real numbers.
Restaurants and takeaways, bakeries and commissary kitchens, food manufacturing and cold storage, supermarkets with in store kitchens, and any mixed use building with a restaurant on the ground floor and apartments above. That last one is the most common version in this borough, and it is also the one where a roof failure is the most disruptive, because the leak lands in somebody's apartment.
MLM Construction Group installs and repairs commercial flat roofs across Brooklyn, Queens, Manhattan, Staten Island and the Bronx, licensed under NYC DCWP HIC #2130570 and fully insured. Call (516) 713-9199 for a free roof assessment and a written scope.
Both are single ply membranes with heat welded seams, but PVC is formulated to resist oils, fats and chemicals, and TPO is not built for that. On a building with a commercial kitchen exhaust, that difference decides whether the membrane around the fan survives. On a building with no grease exposure, TPO is often a perfectly good choice.
Most single ply membranes rely on plasticizers to stay flexible. Animal fats and cooking oils leach those plasticizers out, so the membrane hardens, shrinks slightly and goes brittle, then cracks. The damage shows as a ring around the exhaust fan where the deposit is heaviest, while the rest of the roof still looks fine.
If there is a cooking exhaust discharging onto the roof, PVC is the standard specification and it is specified that way because of long field evidence. That covers restaurants, takeaways, bakeries, commissary kitchens, food manufacturing and mixed use buildings with a kitchen on the ground floor.
Sometimes. If the rest of the membrane is sound and the damage is confined to the grease zone, a compatible section can be cut out and replaced, carried well past the edge of the affected area. It depends on what the existing membrane is, its age, and whether the two materials weld or bond compatibly at the seam.
Compare the membrane in the circle around the exhaust fan with the membrane twenty feet away. Look for discoloration, a hardened or chalky surface, shrinkage pulling the sheet away from a curb, and cracking that follows the shape of the deposit rather than the shape of the roof.
It generally costs more per square foot than EPDM. On a building with kitchen exhaust that comparison is misleading, because the cheaper membrane fails early in the one area that is hardest and most disruptive to repair. We quote both where both are genuinely viable and explain what the difference buys.
Yes. PVC is typically light colored and reflective, so it absorbs far less heat than a dark roof. On a Brooklyn flat roof in July that is a measurable difference in what the air conditioning has to work against, and it also reduces the thermal cycling the membrane itself goes through.
Yes. The assessment is free and the scope is written, naming the membrane, the detailing at every curb and penetration, and the warranty terms. MLM Construction Group is licensed under NYC DCWP HIC #2130570 and fully insured. Call (516) 713-9199.