Pest Management and Flat Roof Construction

Many times the source of a pest problem is right in front you, seemingly impossible to figure out, but obvious once revealed. And sometimes the solution to your pest issue may be right above you.

Flat roof construction can be found all over the country from residential settings to commercial office and industrial buildings to high rises, and even around the most sensitive accounts your company services. Often there are just small sections of the overall construction that have a flat roof, and other times it spans areas tens of thousands of square feet. Each one will have a different set of challenges and conducive environments that can have all the elements needed for pest populations to explode. All of us should perform a routine inspection to the exterior of our accounts in an effort to identify or prevent pest pressure. But do we typically have the flat roof area as part of our routine exterior inspections? Because flat roofs often contain the same necessities that many pests need for survival, perhaps we should.

ALL THE RIGHT ELEMENTS. Almost all living organisms have a deep desire for survival and to reproduce. Even when conditions are not the greatest, the survival instinct will kick in, allowing them to adapt and overcome the situation. And, when all the right elements are available (food, water and shelter), populations really flourish. So can we find that ideal combination of pest-friendly elements on a flat roof? Definitely, yes!

Flat roofs commonly have either standing water or drains that can supply all sorts of vermin with the needed moisture requirements for survival, or in the case of mosquitoes and other pests, a breeding site. Leaf litter, air conditioning (A/C) units, ridge vents, block caps, and equipment storerooms all make great harborage locations for any number of pests, as these areas are normally left undisturbed for long periods of time. Food sources can range from nuts, tree buds and vegetation that have fallen from surrounding trees to an abundance of dead insects, fungus or even human litter. To complicate matters, it’s not uncommon to find rooftop gardens or green spaces being tended to near a flat roof. Although such spaces are beneficial for lots of reasons, they can also lend to an escalation in pest populations.

WHAT PESTS AREN’T THERE? Because the roof is just an extension of the exterior environment, the list of pests that can be found on a flat roof is only limited to the types of pests you would generally find in your geographical area. Numerous ant species like odorous house ants, carpenter ants, pharaoh ants, acrobat ant and fire ants, to name a few, can thrive in these areas. On the interior, cockroach species like smokybrown, American, and Turkestan will have populations reaching high numbers before detection. Mice and rats can use the flat roof as a staging area for an all-out assault by gaining entry into ceilings and wall voids that allow them access to interior areas. Mosquitoes can breed in the standing water from rain water or A/C units left behind by the poor drainage commonly associated with this roof style. Birds and other wildlife like raccoons and squirrels will use the equipment housing as suitable homes for their young. Stinging pests like wasps and yellow jackets, occasional invaders and overwintering pests are also an issue — the list just goes on and on.

CHALLENGES WITH FLAT ROOFS. First and foremost is SAFETY! There is always a danger factor associated when working around heights and only individuals who have been properly trained on the inherent risk should work on flat roofs. Before accessing the roof, you will need to be aware of your company’s policies as well as the client’s policy for working around heights. Many clients will require you complete their safety training program, notify them each and every time before accessing the roof or even require that you are escorted by one of the members of their safety team. Then there’s the task of just gaining access. This may be as simple as finding the door that leads out to the roof, or as challenging as needing ladders or lifts. If access on a routine basis is difficult to obtain, the use of binoculars from a higher vantage point may come in handy.

OK, now that you’re on the roof, what about your tools of the trade? Cockroach/insect baits, dusters, compressed air sprayers, rodenticides and all those other tools you normally have at your fingertips need to be transported to the roof with you, without limiting your mobility. It may be a good idea to create a smaller tool kit that allows you to move freely and safely, but also has everything you would need to solve the pest issues.

IDENTIFYING PEST ENTRY POINTS. Identifying pest entry points on a flat roof will require you to have a basic understanding of the construction methods used. Also, having access to building maintenance plans can save hours of hunting for pest-conducive locations. The building maintenance plans can be useful in locating old plumbing or equipment no longer in use that may have been left on the roof or built around. Many times, ridge vents and metal flashing has pulled away, giving easy access for pests to enter the interior ceiling and wall voids. The use of mirrors on extension poles works well in identifying these locations. Other areas of concern include vent pipes or exhaust fans that have not been properly screened, again allowing easy access. Identifying these deficiencies will be beneficial for both the client and your program.

FINAL THOUGHTS. It doesn’t matter if a roof is on the second story, a high rise or anywhere in between. Consideration should be given to flat roofs as potential points of origin for pest pressures. Understanding that the pests may be breeding and gaining access around the roof even though they are commonly found at the ground level will help you to solve and prevent pest problems that others cannot. Many clients may not understand the importance of these inspections and it will be up to you to educate them. First and foremost, be safe!

Copesan is an alliance of pest management companies with locations throughout North America. To learn more, visit www.copesan.com.

Christian Wilcox, A.C.E., is the technical director for McCauley Services in Central Arkansas. He is chair of the Copesan Technical Committee, serves on the NPMA Technical Committee and is an ESA member.