How do I permanently get rid of roaches in my house?

A cockroach sighting is rarely an isolated incident. For every roach you see, there are likely many more hiding in walls, under appliances, and inside cabinets. The good news is that with the right combination of treatment and prevention, it is possible to eliminate them permanently but it requires tackling the problem in the right order.

The 3-phase Cockroach extermination and prevention approach

Step-by-step: how to eliminate all the cockroaches

• Identify the species and hotspots: The two most common species in Canadian homes are German cockroaches (small, fast, prefer kitchens and bathrooms) and American cockroaches (larger, often found in basements and drains). Identifying which species you're dealing with is important because they behave differently and require different treatment approaches. Check under appliances, inside cabinet hinges, around pipes, and behind the refrigerator for droppings, egg casings, or live activity.

• Apply gel bait in harbourage areas: Gel bait is one of the most effective cockroach treatments available and is the method most professional pest exterminators rely on for German cockroaches. Small dots of bait are placed in cracks, under appliances, inside hinges, and along baseboards. Roaches consume the bait and carry the active ingredient back to the nest, killing others through contact and secondary ingestion. Do not use spray insecticides at the same time because they repel roaches away from the bait and reduce its effectiveness.

• Use boric acid or diatomaceous earth in wall voids: Boric acid powder applied lightly along wall voids, under kick plates, and inside wall cavities creates a long-lasting barrier that damages roaches' exoskeletons and digestive systems. Diatomaceous earth works similarly because both are low-toxicity options that remain effective for months as long as they stay dry. Apply a very thin, barely visible layer because roaches avoid areas with heavy dustings.

• Seal cracks, gaps, and entry points: Cockroaches enter homes through surprisingly small gaps such as around pipes, under doors, through wall cracks, and via shared walls in apartments or townhomes. Use silicone caulk to seal gaps around plumbing, install door sweeps on exterior doors, and check behind the stove and dishwasher where pipes pass through walls. Sealing harbourage sites is just as important as treatment because it eliminates the hiding and breeding spaces roaches depend on.

• Eliminate food, moisture, and clutter: Roaches need three things to thrive: food, water, and shelter. Store all food in sealed containers, clean up crumbs and grease immediately (especially behind and under appliances), fix any dripping taps or leaks under sinks, and reduce clutter particularly with cardboard boxes, which is a popular cockroach harbourage site. Empty garbage bins regularly and keep them tightly covered. These changes don't just prevent re-infestation as they usually make your treatments significantly more effective.

Treatment options — DIY vs pest professional

When to call a pest manage professional for cockroach extermination

DIY treatments can work for minor infestations caught early. But if you're seeing roaches during the day, finding egg cases in multiple rooms, or if treatments haven't worked after two to three weeks, a professional is strongly recommended. Cockroach infestations grow exponentially — the sooner a licensed technician assesses the situation, the less damage, cost, and disruption you'll face.