Building Out Pests of Interior Spaces

Pests are more than a nuisance. Flies carry staph, E. coli and salmonella and can be feeding on feces and garbage one minute, and resting on food and food prep surfaces the next. Exposure to cockroaches can cause asthma and trigger asthma attacks. They also carry germs that can cause pneumonia, diarrhea and food poisoning. Rodents transmit hantavirus, typhus and SARS, and can chew on electrical wiring, causing shorts and fires. No school should put up with these pests, or unnecessary pesticide use.

Designing, maintaining and operating school buildings and grounds with a focus on pest prevention pays off in fewer pest complaints — up to 90 percent fewer — and less pesticide use. This article focuses on pest proofing in kitchens and cafeterias, classrooms and other interior spaces in new construction and existing school buildings.

Well Designed Contributes to Pest Free
Kitchens provide a particular challenge to pest management with many opportunities for pests to access food, water and harborage, the elements they need to survive and thrive.

To discourage pests, flooring in food service areas should be durable and easy to clean. Traditional ceramic tile floors have a tendency to crack and deteriorate over time, allowing water and organic material to penetrate and attract pests. Epoxy finishes and sealed concrete floors are growing in popularity and, if maintained properly, do not provide harborage for pests.

Failure to plan enough storage space leads to unnecessary clutter and items being stored on the floor and stacked against walls. Dr. Michael Merchant, professor and extension urban entomologist at Texas AgriLife Extension Service, recommends space-efficient stainless steel shelving on wheels and 12 to 18 inches of clearance under all shelves to allow for inspection and cleaning. Wire-rack shelving prevents food particles and other debris from collecting on shelves.

Dry floor drains are an open invitation for pests to enter your facility, especially American cockroaches and rodents. Ensuring that traps in infrequently used drains are filled with water can prevent pest entry. Mineral oil can also be added to slow evaporation. Alternatively, rubber trap guards can be used to seal infrequently used drains, while allowing water to pass through when the drain is needed. All drains should be located in accessible places, with easily removed covers, so they can be inspected and cleaned properly.

Sealing Out Pests
Suspended ceilings, which leave space above for ductwork or wiring, “can become super-highways for rodents,” says Dr. Chris Geiger, municipal toxics reduction coordinator for the San Francisco Department of the Environment. All penetrations for ducts, wires or pipes in these and other areas should be sealed to prevent rodents from traveling easily from one part of the building to another, using fire-stop sealant where recommended or required.

According to Geiger, “To facilitate easy inspections, plumbing and electrical areas of the building should be designed with easy access in mind.” Leaking pipes provide a source of water for pests including mold. Mechanical, electrical and information technology rooms or closets generally have penetrations that may require inspection and maintenance, and also often contain heat sources that are attractive to pests.

Cockroaches are thigmotactic, meaning they prefer to rest where surfaces touch both the top and bottom of their bodies. This makes crevices behind bulletin boards, paper towel dispensers, mirrors and even paper announcements tacked to the wall good hiding places. These are especially attractive to roaches when they are located in kitchens, which can also provide convenient food and water sources. Permanent wall-mounted fixtures should be sealed around the edges. Papers should be taped all the way around the edges to prevent cockroaches from getting underneath.

Remember that even with initial pest-proofing or building renovations, school facility managers should conduct a thorough walk-through annually to check for cracks and crevices, broken door sweeps, moisture and mold growth, termite tunnels and bird roosts. Although a contracted PMP may be providing regular updates, school staff should also conduct their own evaluation as part of their oversight. A written IPM inspection checklist can be used for periodic inspections, listing each area to be inspected and providing a space to note needed repairs. Geiger summarizes, “It all boils down to food, water, harborage and access. If you can minimize those things, you’re making good progress towards an effective IPM program.” 

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