A single-family residence in Calixa-Lavallée with an attached double garage was the site of raccoon infiltration in the space between the ceiling of the garage and the floor of the master bedroom above. A small rural municipality in the Montérégie region neighbouring Verchères and Contrecœur, Calixa-Lavallée offers a peaceful, mostly agricultural environment, where woods and cultivated land border inhabited areas, which encourages the movement of wildlife to buildings. The owners had first heard nighttime scratching noises, then a strong smell of ammonia had begun to permeate the master bedroom. The situation quickly worsened with the discovery of moisture stains on the ceiling, caused by the accumulation of urine in the insulation. The Nova Extermination team took charge of the emergency response to put an end to this situation before the structural damage worsened.
Evaluation of the garage-home interface area
The junction between an attached garage and the inhabited part of a house is often an area of weakness in the building envelope. The inspection targeted the soffits above the garage door, the intersections between the shear wall and the roof of the garage, the electrical and plumbing duct passages between the two spaces. Two entrance areas were identified: an opening at the top of the shear wall on the kitchen side and a space between the soffit and the fascia at the north corner of the garage. Stuck hairs on the metal edges, fingerprints in the dust and traces of urine on the insulation confirmed an occupation of several weeks. The presence of a nest composed of torn insulation materials and dry leaves suggested a female in the maternity period.
Full capture of the group present
The raccoon capture plan took into account the possibility of a family with young. Live-trap cages were installed at the two identified entrances inside the garage, and a third cage was placed outside along the most used travel path. The baits were renewed at each morning check. In four days, one adult female and three cubs were captured. The young, still unable to move on their own, were removed from the nest after the mother was captured. The complex has been relocated to an appropriate natural environment, in accordance with provincial regulations. Surveillance was maintained for two additional days to exclude the presence of an adult male not yet captured. Our accomplishment on a comparable case in the region illustrates this sequential approach.
Decontamination and rehabilitation of the contaminated area
Decontaminating the attic and similar spaces between ceiling and floor is an essential step after a raccoon infestation. The urine-soaked insulation was completely removed by suction and evacuated in airtight bags. The wood surfaces of the framework were treated with an enzymatic disinfectant to degrade organic molecules and neutralize odors. Moisture stains on the ceiling of the master bedroom were inspected to rule out structural damage. A new rigid panel insulation was installed to restore thermal performance and prevent any re-colonization by the effect of hot air intake. An olfactory check carried out 48 hours after the work confirmed the complete disappearance of the odours.
Closure of access and prevention adapted to garages
The two entry points were closed with materials adapted to the constraints of a garage: galvanized steel panel on the opening of the shear wall, and UV and weather-resistant exterior caulking on the soffit-fascia junction. The entire perimeter of the garage was inspected and the risk areas reinforced with commercial grade caulking. Homeowners have received specific recommendations for garages: keep the garage door closed outside of periods of use, check the condition of soffits and roof junctions annually, and eliminate any accessible food sources in the immediate vicinity. Our case study on a similar issue and our realization on wildlife prevention complete the resources available to landowners in the area.