In Varennes, on the South Shore, an owner of a small commercial building housing offices and a warehouse, located near the industrial zone near Contrecoeur, contacted our team after discovering rat droppings in the storage area. The building, built of concrete blocks and with a flat roof, had architectural features that were particularly conducive to rodent infiltration. Our caulking and exclusion specialist carried out a comprehensive assessment to design an action plan adapted to the constraints of a mixed-use office and warehouse building.
Particularities of mixed-use commercial buildings
Commercial warehouse-office buildings present unique challenges when it comes to exclusion. Loading docks, sectional panel garage doors and computer or electrical cable crossings between the office and warehouse areas are all weak points that must be treated with care. In this case, the inspection revealed a gap of more than two centimetres under the two garage doors, loose caulking joints around the windows on the north façade, perforations in the hollow concrete blocks around the water and gas inlets, and a warehouse ventilation duct with rusted and partially torn off the exterior grille.
Inspection of the flat roof revealed that several ventilation duct and electrical cable penetrations were never properly sealed during the original construction. These openings, although small in appearance, are more than enough to allow an adult rat capable of compressing its body through an orifice about two centimeters in diameter. This is common in the region’s industrial buildings.
Exclusion plan adapted to the industrial context
The work began with the loading docks, the area most frequented by rodents due to food odors coming from a customer who rented the building. Brushed stainless steel sills with compression gaskets were installed under each garage door, and the side seals were checked and reinforced. For the hollow concrete blocks, the technician used a specialized technique of filling the cavities with closed-cell polyurethane foam before applying a cement coating to the exterior surface. Cracks around the windows were filled with high-performance exterior silicone caulk, compatible with the metal substrates of the frame.
On the roof, each duct penetration was fitted with lead or EPDM rubber sealing collars depending on the type of duct and then covered with a six-millimetre mesh stainless steel mesh secured with corrosion-resistant countersunk screws. The ventilation duct of the warehouse has received an aluminum protective cap with integrated mesh. To confirm the tightness of all the interior ducts, a specialized smoke test was recommended in addition to the surface work, revealing breaches that were invisible to visual inspection.
Follow-up and preventive plan for business management
A semi-annual follow-up contract has been established with the owner, including a visual inspection of all the points treated and a verification of the risk areas before and after the winter season. Employees have received awareness training on best practices: waste management, closing loading doors between deliveries, prompt reporting of any signs of animal activity. These behavioral measures are essential to complement the physical work of caulking. It is also recommended not to allow cardboard or packaging materials to accumulate in loading areas, as these materials provide shelter and nesting material appreciated by rodents. The installation of airtight lidded bins in the warehouse and delivery area considerably reduces the attractiveness of the site for rats and mice in the winter period. Check out our Pest Prevention Plan to learn more about long-term strategies tailored to businesses. Our extermination team in Varennes provides fast and professional service for businesses in the region. See also our previous work in commercial exclusion. With Nova Extermination, every intervention is documented and guaranteed for your peace of mind.