Cockroaches in your apartment building: BC tenant protocol

German cockroach biology in apartment buildings

German cockroaches (Blattella germanica) are the dominant species in Metro Vancouver rental buildings, and their biology is specifically adapted to multi-unit residential environments. They thrive in warm, humid microclimates near water and food sources — the shared kitchen and bathroom plumbing stacks that run through every floor of a concrete high-rise create ideal habitat. A female German cockroach produces an egg case (ootheca) every 3–4 weeks, containing 30–40 eggs; at room temperature, those eggs hatch in approximately 3 weeks. A single introduced pair can produce a population of several hundred within 3 months under optimal conditions. At that density, they begin migrating into adjacent units, typically moving first through shared wall voids behind kitchen cabinets, through holes around common plumbing penetrations, and under corridor doors with inadequate sweeps.

Multi-unit migration mechanics

German cockroaches move between adjacent apartments through shared kitchen plumbing stacks, electrical conduits, common service walls, and door-bottom gaps in shared corridors. A single severely infested unit can affect adjacent units within 2–4 months. Treating only the affected unit drops the local population, but adjacent-unit populations migrate in to fill the ecological void within 4–8 weeks of treatment. The original unit's infestation rebuilds — and the cycle continues until either the entire migration corridor is treated or the structural pathways between units are sealed. This is why property managers and strata councils who authorize single-unit-only treatments spend more money over 24 months than those who authorize building-wide protocols on first response.

What building-wide treatment looks like

Coordinated treatment of the vertical kitchen stack (e.g., units 604, 704, 804 sharing the same plumbing riser) and all units horizontally adjacent to known infestation. For a typical confirmed infestation, Wild Pest's protocol covers the affected unit plus the 4 adjacent units (above, below, left, right) and the 2 units sharing the same vertical stack. Treatment approach: commercial-grade gel baits placed inside all cabinet bases, behind refrigerators, and in plumbing access areas, combined with perimeter dust applications in wall voids. Gel baits are the preferred tool because they don't require tenant food-removal preparation, and German cockroaches preferentially feed on gel over other food sources when bait rotation keeps them novel. Monitoring traps are deployed in adjacent units to detect migration before it establishes as a new infestation.

RTA responsibility: who pays

In a rental building, cockroach treatment is landlord scope under RTA Section 32 for the same structural reasons as mice: the migration pathways (shared walls, plumbing penetrations, building infrastructure) are part of the building, not the tenant's responsibility. Tenant fault would require specific evidence — typically, that a tenant introduced a severely infested item into the building and the building had no prior history. In a building where cockroaches have been present for multiple tenancies or are found in common areas, tenant fault claims fail. German cockroaches in Metro Vancouver rental buildings are almost always building-environment introductions, not tenant introductions.

Tenant's role

• Report promptly to landlord or strata management in writing, with photos of live bugs and dropping evidence.
• Cooperate with treatment access — RTA Section 29 requires 24-hour notice for entry; treatment access for maintenance cannot be unreasonably refused.
• Maintain food hygiene: sealed containers, prompt waste removal, no overnight food on counters, clean grease from stove and range hood.
• Report any visible gaps around plumbing or wall penetrations to building management — these are structural pathways that the landlord should seal.
• Do not apply your own over-the-counter cockroach sprays — aerosol sprays scatter roaches and disperse populations into adjacent units, worsening building-wide pressure and making professional treatment less effective.
• Document any property damage (contaminated food, damaged items) for a potential RTB compensation claim if treatment is delayed.