No. For 10 years, the patented Grease Guard filter systems have been protecting roofs in the food service industry. Just like a home kitchen, cooking causes grease to become airborne. Commercial restaurants exhaust this grease to the outside where it accumulates on the rooftop. Roofing contractors have been using the Grease Guard products on industrial facilities as well as in markets such as food processing and plastic production as well as for industrial processes such as machining operations and hot oil quenching.
The Grease Guard helps you comply with 40 CFR 122.26 [1997] when used as a Best Management Practice [BMP] in your Stormwater Pollution Prevention Plan [SWPP]. Storm water permits require that all potential sources for stormwater runoff (such as rooftops) must be identified in the SWPPP and that BMPs must be used to control the pollution that results from this runoff. The Grease Guard filters can be identified as a BMP for capturing and eliminating oily run-off from your facility's rooftop ventilation systems.
That might seem like a reasonable alternative. But typical absorbents are quickly damaged by the effects of ultraviolet. The stones on a built-up roof prevent a boom from lying flat against the surface and effectively blocking the leak. There is no barrier to prevent the grease and oil from passing through to the roof. The lightweight materials will not stay in place. And they are not designed to allow the rooftop to breathe properly.
Put simply, they just don't work well. They may help, but require a lot of "babysitting". When it rains the oil will float to the surface and overflow, defeating the purpose of the unit. The weight of sand can exceed the roof specs and requires constant replacement. Plus, it's difficult and can be unsafe transporting unused sand onto the roof and removed soiled sand. The Grease Guard is designed to channel away water and absorb and retain the oil.
To ensure adequate coverage, extend the replacement cycle and allow for changes in leak pattern. Your initial measurements should be where the oil and grease actually drip. Adding 30" allows for 15" of filter to the left and right, front and back of the leak area. You may want to add a little more in the case of heavy leakage or a little less if leakage is minimal. It does not need to be exactly 30; the 30 is a rule of thumb and is meant as a guide to help in sizing your unit properly. The larger your unit, the more absorbent capacity it has.
Typical installations will not. The unit is designed in such a way that a tight-fitting filter and the weight of the unit are all that's needed to hold it in place. Steeply pitched roofs may require the use of elevation brackets that level the Grease Guard.
Typical applications do not require additional mounting hardware. There may be some applications such as near airports that require further measures, but the low profile units are typically not subjected to high wind forces.
After proper installation, you need to set a regular schedule for when and how often you will be checking and replacing the Grease Guard filters. We recommend checking it the first week after installation, one month after installation and three months after installation. If the unit is catching grease from a vent where the leakage is fairly consistent over time, by following this format, you will have a pretty good idea of how to then set your maintenance schedule. Often there are other maintenance inspections or functions on the rooftop, such as HVAC inspections, that must be done regularly and the Grease Guard inspection can become part of this routine.
Depending on the leakage pattern, there may be one section that is more saturated than others. The Grease Guard has been designed so that the filters are modular and come in sections. You may wish to rotate sections and switch a "fresher" filter with one that is nearing saturation. Once the unit is fully saturated, oily residue will be washed away with the rain, so it is important to provide regular inspections.
You've heard the old saying to "measure twice and cut once;" that applies here, too. We recommend carefully measuring and cutting for your first installation and then making a template for future use. That will save time as well as ensure a consistent, proper fit.
Yes. In fact, just about any application can be customized. Usually there's a stock size available that will work. The times when a custom unit might be required are if there are obstructions sticking out of the roof that would interfere with the framework. But even if there are obstructions, remember that the frame should roughly be centered over the leak area, and does not need to be perfectly centered around the vent or curb. And since the filter gets cut to size, as long as the obstruction is within the open part of the framework, the filter can be cut around the obstruction.
