A residence built in the 1940s, well preserved in a wooded area of Saint-Marc-sur-Richelieu on the South Shore, suffered significant infiltration by raccoons at the roof level during the spring. The owners had noticed asphalt shingles torn off the north slope of the roof, then intense nighttime noises in the frame confirmed the presence of animals. Saint-Marc-sur-Richelieu, a residential city whose neighbourhoods border the green spaces linking Saint-Lambert and Chambly, and whose old sectors retain large trees that serve as travel corridors for wildlife, is particularly exposed to raccoon intrusions. The specificity of an old house, with its original architectural elements, required careful intervention to solve the problem without damaging the building. The Nova Extermination team took charge of the case with the attention it deserved.
Challenges of inspecting an old building
Houses built before 1960 have characteristics that encourage animal infiltration: solid wood frames with numerous interstitial spaces, wood soffits subject to decomposition, and intersections between successive additions that are often poorly sealed. The inspection covered the entire perimeter of the roof, all four slopes, chimney connections and junctions between the main house and a newer addition. Three points of vulnerability were identified: the shingles torn off the north slope, a rotten wood soffit at the back of the building and a space around the brick chimney. The colonized frame space extended over a large area, with a large nest installed in the deepest corner, sheltered from temperature variations. Abundant biological evidence confirmed an occupation dating back several weeks.
Capture adapted to the fragility of the old structure
Catching raccoons in an old frame requires special precautions to avoid damaging the aged wood elements. The cages were installed at the identified entry points with additional supports so as not to exert undue pressure on the weakened structures. The traps were checked daily by a technician trained in wildlife management in sensitive environments. Two adults and four juveniles were captured over seven days. The young, which were still not very mobile, were manually removed from the nest once the mother was captured, according to our standard procedure for family groups. The complex was relocated in accordance with provincial regulations. A 48-hour follow-up with no activity confirmed complete resolution of the infestation. See our work on a comparable old building for details on our approach.
Decontamination with preservation of original materials
The decontamination of the attic of an old house must be carried out without damaging the period structural parts. Our team avoided the use of corrosive products that could degrade the old wood. The mechanical suction of the droppings, combined with an enzymatic disinfectant treatment applied with a low-pressure spray, effectively treated the surfaces without excessively impregnating the woods. Nesting material has been completely removed. A biological odor neutralizer was applied as a finish to remove residual pheromones. The detailed report of the work given to the owners can be used for any heritage or renovation subsidy approach. The complete disappearance of odours, observed during the follow-up carried out two weeks after the intervention, testified to the effectiveness of the treatment.
Building restoration and sustainable preventive measures
The closure of the entry points on an old house respects the architectural character of the property. The torn shingles were replaced with identical asphalt shingles, and discreet metal protection was built into the most exposed areas under the new shingles. The wood soffit was repaired with wood treated to original dimensions and painted in combination. The chimney junction was reflected and reinforced with steel mesh concealed in the mortar. Our animal capture and relocation service remains available for any possible recurrence. Maintenance measures have been included in an annual schedule given to the owners, including the inspection of the soffits and siding each spring and after each storm. Also consult our work on another file on the South Shore to appreciate the consistency of our preventive approach in wooded areas.