Photo courtesy of Coastal Enviro-Solutions Inc., Watertown, Conn.
Photo courtesy of Coastal Enviro-Solutions Inc., Watertown, Conn. 
Photo courtesy of Coastal Enviro-Solutions Inc., Watertown, Conn. 
Photo courtesy of Coastal Enviro-Solutions Inc., Watertown, Conn.
Photo courtesy of Coastal Enviro-Solutions Inc., Watertown, Conn.
Editor's note: The following information reflects the author's opinions, not necessarily those of NRCA or Professional Roofing.
Issues concerning rooftop contaminants are being examined closely these days by some state and federal agencies, roofing materials manufacturers and building owners because of the ongoing problems and hazards certain contaminants can create. These contaminants include animal fats, oil and grease, which can cause premature roof system damage and raise questions about warranty coverage.
According to Pat McGrady, vice president of technical and warranty services for Carlisle SynTec Inc., Carlisle, Pa., "An integral part of any building owner's decision-making process when selecting a commercial roof system should be warranty coverage. One of many factors having potential to [affect] warranty coverage is rooftop contaminants. Fats, oils and grease are among those contaminants frequently coming in contact with roofing materials."
Most large roofing materials manufacturers seem to agree with McGrady, as well as the fact that rooftop contaminants are recognized as a growing problem in the roofing industry. Whether you are a roofing contractor, roof consultant, architect, roof system designer or building owner, you need to be aware of the serious problems rooftop contamination is causing and the effects it is having on the environment and roofing industry.
The environment
There are thousands of commercial kitchens, restaurant chains and food-handling businesses in the United States that generate fats, oil and grease every day. A majority of fats, oil and grease that spills onto roofs and into rooftop drains generally is discharged directly to sewer systems and, in many cases, to lakes and streams without treatment. This water is not remediated before being discharged into the environment. This does not exclude runoff from rooftop grease.
This kind of pollution is a growing environmental hazard and concern that is being looked at closely by some local and federal agencies.
Here is how serious the problem is: The Nov. 3, 2003, issue of Nation's Restaurant News discussed Atlanta's sewer problem. Atlanta's sewer systems made world news in March 2003 when the metro area was ranked third from last among 215 international cities because of its sewer problem, according to a survey of European business executives who had lived in Atlanta. Another interesting point is during 2000 and 2001, Atlanta had more than 700 sewage system overflows, and 50 percent of those were restaurant grease-related.
Basically, there are three types of sewers: sanitary, storm and combined. Most cities have sanitary and storm sewer systems. A home sewer is connected to a sanitary sewer system. This system of pipes goes to a sewer treatment plant or public-owned treatment works (POTW) facility. At a POTW facility, the sewage is treated and discharged to lakes or streams. A storm sewer is where rainwater goes into gutters along streets. This water generally is discharged directly into lakes and streams without treatment. Because this water is not remediated before being discharged into the environment, rooftop grease that spills into storm drains is becoming a growing concern among some state and federal agencies.
In response to the U.S. Clean Water Act, programs have been established by regulatory agencies to achieve the following objectives: to prevent industrial waste from interfering with POTW facility operations; prevent contamination of POTW facility sludge; prevent pass-through of pollutants to POTW facilities; and protect POTW facility workers from harmful exposure. There are about 1,600 POTW facilities in the United States.
The U.S. Environmental Protection Agency (EPA) also is taking a closer look at fats, oil and grease that are spilling into storm water and sewage systems. For example, all industries that generate and discharge fats, oil and grease and other potential pollutant sources are faced with the EPA's Storm Water Pollution Prevention Plans and Best Management Practices.
In addition, the National Urban Runoff Program and Clean Water Act (CWA) report submitted to Congress during the 1980s identified contaminated storm water as one of the causes adversely affecting water quality. Congress amended CWA in 1987 to require EPA to address storm water runoff. Federal regulations were promulgated in 1990 with the first general permits issued in 1992.
Two types of storm water general permits were issued beginning Sept. 9, 1992. The first was for discharges associated with industrial activities, commonly referred to as the Baseline Industrial General Permit (BIGP). The second permit was for discharges associated with construction activities. BIGP covered all facilities except those covered under the construction permit.
From California to the East Coast, politicians are turning new grease requirements into law. In Los Angeles, local officials proposed amendments to municipal ordinance LAMC 64.30 that would require all food service establishments to use best-management practices to reduce grease discharge. Failure to implement such practices would require installation of underground interceptors that would cost thousands of dollars. The food service industry has the same problem with grease that is spilling on their roofs and into storm drains.
Roof systems
Unfortunately, the problem goes beyond storm water pollution. As roofing professionals know, fats, oil and grease contaminants can cause premature roof system damage.
According to David R. Hawn, president of Dedicated Roof and Hydro-Solutions, Centreville, Va., "When grease comes in contact with roof systems, it causes most roofs to soften, delaminate, blister or crack, depending upon the specific material."
This, he says, can lead to leaks, internal damage and environmental hazards.
David A. Carl, manager of Guarantee Services Unit for Johns Manville, Denver, agrees. He says, "Failure to contain grease and oils may result in shortened roof system life and jeopardize a manufacturer's warranty."
Because grease is flammable, rooftop grease creates a potential fire hazard and may violate local fire or building codes. Often the basis for local building and fire codes, the National Fire Protection Association's (NFPA's) NFPA 96, "Standard for Ventilation Control and Fire Protection of Commercial Cooking Operations," states rooftop termination should be arranged or provided with the ability to drain grease out of any traps or low points formed in the fan or duct near the termination of the system into a collection container that is noncombustible, closed, rainproof, structurally sound and will not sustain combustion. In addition, a grease-collection device that is applied to exhaust systems should not inhibit any fan's performance.
Local building, fire and health codes often have specific requirements for restaurant exhaust systems, including rooftop exhaust fans, ventilators and grease-control equipment.
Grease spills also create a slip hazard for those who work on roofs. If a slip occurs, you could face a costly workers' compensation claim or lawsuit.
To get this ongoing problem under control, the roofing industry and building owner community need to become more vigilant in addressing this problem. The industry will see improvements when more roof consultants, architects, builders and roofing materials manufacturers start including rooftop grease-control equipment in their specifications. It's that simple.
McGrady explains: "Where you have a rooftop exhaust fan that is generating fats, oil or grease, you always will have a grease problem on the roof. Before the roofing process takes place, research should be conducted to determine what chemicals will be emitted (if any) and to what degree. Options available in the market to deal with this situation should be included in project specifications."
If grease-control equipment is not installed during a roofing project and a business that occupies the space starts introducing fats, oil and grease contaminants to a new roof system, most of the time it's too late to prevent roof system damage.
If a contractor does not install proper grease-control equipment, he could expose himself to legal liability. Failure to include rooftop accessories or equipment required by specifications or a manufacturer also could create possible legal issues for the roof consultant, architect, builder and/or roofing materials manufacturer. For example, if grease-control equipment is required in a specification or required by a roofing materials manufacturer and the contractor overlooks this equipment, someone is going to be held accountable for problems related to rooftop grease. In most cases, the accountable person will be the contractor or the person who wrote the specification.
Options
There are some simple, cost-effective options to control rooftop grease spills, such as regular maintenance check-ups and installing chemically resistant membranes and grease-control equipment.
McGrady notes: "A systematic approach to checking all rooftop units capable of emitting any substance onto the roofing surface should be a high priority. A quarterly walkover of the roof to check all rooftop units that emit these substances is an excellent means of preventing potential problems. Consider the fact that commercial roofing represents a substantial investment by a building owner and its maintenance should be taken seriously. Regular checkups to ensure everything is working properly will go a long way in protecting that investment."
When inspecting a roof system for contaminants such as grease, make note of the typical grease traps, sandboxes, plastic buckets and standard metal catch pans that are being used. These are all great ideas, but none of them seems to be doing an effective job keeping grease from spilling onto a roof. Most of these contraptions either leak or overflow when full. When these devices fill with rainwater, rainwater overflows the grease onto the roof's surface.
Most exhaust fans and ventilators have a standard catch container typically found under the drain spout of the exhaust fan or around the lower base section of the exhaust duct curb. These devices are designed to supposedly catch grease that spills from an exhaust fan. Unfortunately, many of these contraptions fail. They also are difficult to install, clean and maintain. Rooftop grease exhaust equipment that is not protected with the right grease-control equipment will contribute to rooftop grease spills, cause premature roof system damage and even void a roof system warranty.
One solution is to install a simple grease-control system that accommodates a replaceable grease "diaper," which is used with most grease-control equipment for trapping fats, oil, grease, petroleum products and other contaminants. It is different from standard filters or absorbent pads supplied with standard grease-containment or collection systems. Grease diapers collect and trap grease and repel water at the same time. The problem with most standard filters or absorbent pads that come with grease-containment systems is they are not water-resistant. Rainwater could pass through the material and spill grease onto a roof.
More roofing contractors are starting to sell grease-control accessories and preventative-maintenance programs. If you do not offer maintenance programs, there are some outstanding grease-control products that last up to one year without needing to be serviced. You easily can service such products during inspections.
Warranty issues
If left unchecked, rooftop contaminants can make it challenging for a roof system warranty to remain in effect.
Paul Oliveira, product manager of accessories for Firestone Building Products, Carmel, Ind., notes, "It is always best to get a confirmation of the contaminant's impact from the manufacturer."
Most roofing manufacturers exclude damage to a roof system if the damage was created by grease.
"Most roofing watertightness warranties caution about rooftop contaminants like fats, grease and oils coming in contact with the sheet and will not cover damage as the result of their contact," Oliveira says.
When asked whether a warranty covers damage caused by contaminants that spill onto a roof system, his reply was, "No; the affected area will be excluded from the watertight warranty until it is repaired."
Most roofing materials manufacturers have roof system care requirements or standards or a manual regarding roof system inspections, maintenance and repairs. Most requirements are published on the backside of warranties.
Summing up
The bottom line is that most contaminants that contact a roof system will shorten its functional life, cause premature roof damage, void a roof warranty and cause problems with building owners. Good asset management by a building owner requires that protecting a roof with proper grease-control equipment must be taken into account when reviewing the condition and budget for a building's future needs. The sooner building owners understand this, the less roof system repairs will cost them.
When choosing grease-control equipment, make sure the equipment offers easy installation and follow-up maintenance. The equipment should be universal with the ability of attaching it to the duct curb directly under the grease drain spout or source of spillage. The grease-control equipment you choose always should meet industry standards. If in doubt, check with local authorities for approval for your application requirements. NFPA 96 is an industry standard most local authorities follow. Remember, the cost of corrective action is minimal compared with the cost of ignoring the problem.
Joseph Baribeau is president and founder of Coastal Enviro-Solutions Inc., a Watertown, Conn.-based company with offices in California.
Tips for controlling rooftop grease
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