Exclusion Fundamentals

Editor’s note: This article originally appeared in a PCT e-newsletter titled “Smart Exclusion Solutions,” which was sponsored by Xcluder.

Find the source, treat the source. Here are some areas in residences to focus on for exclusion efforts, based on input from a number of PMPs who provide exclusion services:

• Utility line penetrations in and around the structure, including gas lines, plumbing, electric, cable and air conditioning lines.
• Roof lines and roof intersections, particularly those with a pitch change.
• Unique building styles that leave openings under eaves for ventilation.
• Gutters.
• Attic and ridge vents.
• Doors and entryways, particularly sill plate and exterior utility doors without thresholds.
• Garage doors.
• Random holes left open during construction. (These can be the most challenging to identify.)
• Broken wastewater pipes under structures and in walls.

In addition to access points in common with residential structures, such as roof lines and utility line penetration, here are some additional pest entry points to consider that are unique to commercial buildings:

• Customer entry doors.
• Roll-up and overhead doors.
• Dock doors.
• Dock leveler plates.
• Roof-top air conditioning units.
• Floor-to-floor utility line chases, including gas lines, plumbing, electric and cabling.

IMPORTANT CONSIDERATIONS. Doors are obvious entrances for people and pests. Use door sweeps with strong exterior covers and interiors filled with rodent-resistant materials to prevent rodents from gnawing through. Ensure the gaskets are intact around the sides of doors and that astragal seals adequately close the gap between doors.

Although all exterior doors are important, ground-level doors and those associated with ramps are even more important as they’re easy access points.

EXCLUSION IS ONGOING. There’s wear and tear of materials. Doors are constantly being opened and closed and may come out of alignment, expand or contract due to temperature, and door frames may expand at different rates, all of which contribute to creating gaps. Regular inspections are recommended.

• In addition to installing new, rodent-resistant garage or overhead door seals, add weather stripping on either side as a “vertical rodent guard.”
• Rail doors, where cars come into an unloading shed or building, are particularly difficult to seal, yet one where mice commonly enter.
• Be sure to use proper materials for exclusion. Also, exclude to the tolerances of the target pest — note gap and hole sizes that may permit pest entry.
• Use the proper materials. Using insulation products, such as expanding foam (exclusively) and other soft products, are generally ineffective.
• Use stainless-steel mesh products for excluding pests from small openings.
• Birds can be problematic. There are a number of factors that may contribute to bird activity, including bright white roofs, solar panels and simply the location of the building. Solutions should be chosen on a case-by-case basis.

MISTAKES TO AVOID. Be sure to train employees on these exclusion “don’ts”:

• Using only foam to fill gaps and holes isn’t an exclusion strategy; it’s a recipe for disaster. It’s easy to apply, butineffective and can cause more problems than solutions. It makes future exclusion more difficult, as foam needs to be cut away and removed. Foam can be messy, making it difficult to see where a rodent originally chewed.
• Installing standard, rubber or vinyl door sweeps and seals won’t work. Rodents may gnaw through to create a new access point. Use rodent-resistant products.
• Don’t partially seal entryways. Ensure entryways are completely sealed.
• Remember to investigate fireproofing requirements as it relates to exclusion.

LANDSCAPE EXCLUSION. Alert customers to landscaping that may contribute to pest infestations. Suggest they avoid using plants that attract and harbor pests and those that will accumulate trash. Keeping exterior areas clean inhibits pest activity.

Landscape rodent exclusion often involves subsurface barrier installations. In landscapes, use non-decaying materials, such as galvanized hardware cloth or stainless steel screening, high-density cement product and appropriate, long-lasting liquid sealants. There are also newer products on the market, such as stainless-steel mesh “carpet” to prevent burrowing around commercial buildings.

CUSTOMER INVOLVEMENT. There are some exclusion strategies you can’t address, but your customer can. A few examples:

• Trailers that are backed up to dock doors and used for storage can be problematic. The trailers may be used to store everything from pallets and cardboard bales to animal feed. It’s more of a problem when the dock doors are open and there isn’t a tight trailer-to-building seal. You may not be able to provide exclusion services in this case, but you can alert the customer to the issue and explain why it’s important to keep the doors closed.
• If automatic door closure timing mechanisms aren’t set correctly, they may allow pests to enter. It’s important to point this out to customers with doors that open slowly or stick while open. Resetting the automatic door mechanisms is something they can do as part of the pest exclusion process. In some cases pests may actually trigger a door to open.
• Success happens when store employees realize sanitation is part of the pest control solution. Keeping up with employee training is important so staff understands proper trash disposal and to close doors when not in use.