UP ON THE ROOF - AN OVERLOOKED MOUSE RETREAT
When you have uncontrolled mice in an account, and particularly if they are on upper floors, look for a rooftop connection. Mice can, and do, enter accounts from the roof.
1. Caulk/silicone openings around exhausts, equipment, and where lines enter the building
You know that mice are good climbers. They can climb straight up outside walls, especially those that have a rough surface of brick, stone or concrete. They also get to roofs by using tree limbs, cables, phone lines, downspouts, and the like. They can even run upside down along a line for a good distance. Likewise, mice can move from an infested lower level up to the roof where they can establish ongoing populations.
Once on the roof, mice can set up housekeeping there, establishing nests on the roof in piles of debris, or under roofing materials, or in air-handling equipment. They might move into the attic/ceiling void space. But, it’s more likely that mice on the roof will be enticed by warmth and smells (especially in food production accounts) to reach lower levels. They can move down into the building through rooftop vents, ventilators, elevator shafts, and air handling systems. Once inside, mice can use lines or pipes in ceilings and wall voids to go anywhere they want to go in the building.
If you’re aiming all your control efforts at mice on the lower levels or main floor, you could be overlooking the main highway for mice entering the building. Mice from on high could be constantly replacing those that you control below. Periodically inspect roofs, especially in commercial accounts, for signs that mice are living on the roof or reaching it from below (either from inside or on the outside of the building). You may need a ladder or a lift, or a staff member with a key.
Assess the state of rooftop sanitation and rodent-proofing. To keep mice from using the roof as a nesting or travel route, have your customer do the following:
2. Remove stacked building materials and debris.
3. Replace missing or damaged shingles or roof tiles; repair tears in rubber roof surfacing.
4. Add thresholds & weather-stripping to rooftop emergency exit doors.
5. Screen ventilator stacks and vents, including soffit vents.
6. Install or re-install metal flashing on joints and edges, and around chimneys.
7. Prune back tree limbs and ivy that are touching the building.
8. Install rodent guards on conduits and lines that lead to the building.