"Crack" - what is it, definition of the term
A narrow fissure, often created by material fatigue or structural stress, is a slender opening that penetrates a solid surface; such openings commonly serve as entry points and concealment spaces for small rodents, allowing species like rats and mice to access interior environments, navigate between compartments, and exploit hidden habitats for shelter and foraging.
Detailed information
A fissure in a building envelope provides a direct pathway for rodents such as rats and mice to infiltrate interior spaces. Such openings typically arise from settlement movement, thermal expansion, or degradation of construction materials. The size of the aperture determines the species that can exploit it; a gap as narrow as 6 mm permits mouse entry, while larger openings accommodate rats.
Detection relies on visual inspection, tactile probing, and the use of infrared cameras to reveal concealed breaches. Indicators include displaced mortar, splintered siding, and discoloration around joints. In addition, droppings, gnaw marks, and nesting material concentrated near a suspected breach confirm active use by vermin.
Mitigation measures include:
- Sealing the opening with durable, non‑compressible material such as steel wool combined with high‑quality sealant.
- Installing metal flashing or mesh to reinforce the repaired area and prevent future deterioration.
- Conducting periodic surveys of the structure’s perimeter to identify new fissures before they become functional entry points.
Maintenance of the sealant and reinforcement components is essential. Regular re‑application, especially after extreme weather events, preserves the integrity of the barrier and reduces the likelihood of rodent infestation.