In Sainte-Julie, on the South Shore of Montreal, an apartment building manager in the Promenades sector requested our services after the discovery of a rat infestation in the crawl spaces and common walls of his twelve-unit building. Lingering odors and damp stains on the ceilings of a ground-floor unit had alerted residents. The situation presented a concrete health risk for the occupants, due to the pathogens carried by Norway rats in their faeces and urine, including Leptospira interrogans, which causes leptospirosis. The extent of the fecal contamination required a rigorous decontamination service , coordinated with the tenants and respectful of the landlord’s legal obligations. Our team in Sainte-Julie quickly took care of the entire operation from the first call.
Assessing Contamination in a Multi-Unit Setting
The complexity of an apartment building lies in the connectivity of the spaces. Our technicians inspected crawl spaces, pipe penetrations between units, false ceilings in the common hallway and the mechanical room in the basement. Rat droppings, nests of paper and insulating fabric, and decomposing carcasses were identified in three separate areas. The ground floor unit had traces of urine on the joists, confirming a prolonged presence of several months. The air contamination was measurable by the persistent ammonia smell in the common areas, reported by several tenants. Each contaminated area was photographed and recorded in an inspection report given to the owner before work began. We also identified four main entry points for rats into the building, which are essential for the prevention phase that would follow decontamination. This information made it possible to establish a precise intervention schedule to minimize inconvenience to tenants while ensuring maximum effectiveness of treatments. Our multi-residential building decontamination projects document this type of intervention with precision.
Occupied Environment Decontamination Protocol
The major challenge was to carry out the work without imposing a generalized evacuation, limiting the inconvenience for the tenants. A zonal schedule was drawn up: the common areas were treated first, during off-peak hours, to reduce disruptions to daily life. The crawl spaces were emptied of their soiled materials thanks to industrial suction from outside the building, thus limiting the movement of technicians in the units. The concrete and wood surfaces were then given an application of an enzymatic disinfectant that can break down residual organic proteins, eliminating odors at the source rather than masking them. A chlorine dioxide-based odour neutraliser was diffused in the enclosed spaces for two hours, with the doors closed. Tenants of units adjacent to the work areas were notified in advance and asked to ventilate their apartments after the end of each treatment session. Ongoing communication with the manager was maintained throughout the process to ensure transparency and compliance with legal obligations in the rental environment.
Restoration and sustainable preventive measures
After validation of the disinfection by a second inspection pass under UV light, the crawl spaces were reinsulated with a rigid polyisocyanurate type insulation, which is less attractive to rodents than glass wool. The rats’ entrances were located around the edge of the foundation, near the ornamental shrub beds on the street side. Each one was blocked with chicken wire lined with a layer of hydraulic mortar. A quarterly pest prevention program has been put in place to ensure regular monitoring of the building. Tenants also received a fact sheet on good waste storage practices, a key factor in the sustainable management of infestations in collective settings. The cleaning of the common recycling room, identified as a source of food attractiveness for rats, has been integrated into the weekly maintenance protocol. Our recent preventive achievements offer additional examples of sustainable solutions in the South Shore region. For any information, visit the website of our extermination company to contact our teams.