Contrecœur, a city in the Montérégie region on the south shore of the St. Lawrence River between Verchères and Sorel-Tracy, alternates residential neighbourhoods, farmland and a port and industrial sector. Its wooded areas and the abundance of nocturnal insects make it an ideal hunting ground for several species of bats. It is in this context that a log cabin owner noticed the arrival of a colony of bats in the attic of his resort property. Bats entered through natural spaces between the logs, characteristic of this construction technique, and settled in the compressed insulating wool between the joists. Our team in Contrecœur quickly implemented an exclusion strategy adapted to the particularities of this type of construction.
Specificities of the inspection of a log cabin
Log cabins present unique challenges when it comes to bat exclusion. The spaces between the logs, even if properly sealed originally, eventually reopen with the natural movements of the wood over the seasons. Our technician methodically inspected each row of logs on the outer perimeter, paying particular attention to the connection areas with the roof elements, windows and doors. Several active openings have been identified thanks to traces of guano and oily marks left by repeated bat passage. The colony, composed mainly of Little Brown Myotis, seemed to have been established for at least two seasons, which explained the noticeable accumulation of guano in the attic. See our achievement on exclusion in a cottage for a similar example.
The interior of the chalet was also inspected. No bat strayed into the living areas was found, but the smell of guano was noticeable in the upper rooms, especially in hot and humid weather. This comfort factor was an additional reason to act quickly.
Human exclusion and management of natural areas
The exclusion plan took into account the natural character of the building. The unidirectional devices were fixed with reversible fasteners suitable for roundwood, without drilling or permanent anchoring. This approach allows the devices to be removed without leaving visible traces. During the active exclusion, the gaps between the logs with secondary cracks were temporarily sealed with fine steel wool inserted into the joints. This step is essential to prevent bats from seeking other access. Our bat capture service always incorporates this preventive closure step to ensure the effectiveness of the exclusion process.
Our technicians also provided advice on the management of the immediate surroundings of the chalet. Reducing outdoor light sources that attract insects at night, pruning branches touching the roof, and maintaining distances between firewood tanks and exterior walls all help make the property less attractive to bats seeking shelter. At the same time, we suggested the installation of a bat box at the edge of the adjacent woodlot, as part of a respectful capture and relocation approach.
Permanent hemp and natural resin sealing
Once the colony was gone, the joints between the logs were sealed with a caulking product suitable for roundwood, flexible and breathable, in order to follow the natural movements of the wood without cracking over the seasons. The main entry points were covered with painted metal plates carefully matched to the colour of the chalet to maintain its natural appearance. Attic decontamination included full guano vacuuming, enzymatic treatment of porous wood surfaces, and disinfection using a biocide registered for mass timber environments. Nova Extermination provided the owner with a comprehensive report with a recommended maintenance schedule for the next few years, indicating the priority areas to be checked each spring and fall. After a follow-up check carried out at the end of the summer season, the situation was perfectly resolved: the Contrecœur chalet was fully regaining its vocation as a place of relaxation and rejuvenation, without the unwanted presence of bats in its walls or the smells that resulted from them.