How Can You Reduce the Risk of Cockroaches Returning After Treatment?

They Arrived in Something

Cardboard is the main one. Deliveries, packaging, boxes from a warehouse or a shop — corrugated cardboard is warm, dark, tight and often stored somewhere infested before it reached you.

Break boxes down at the door and get them out of the property rather than storing them in a utility room, a garage or under the stairs. It is a small habit and it removes the commonest arrival route there is.

Second-Hand Appliances and Furniture

A used fridge, washing machine, microwave, kettle or toaster is one of the most reliable ways to import a breeding population. The casing voids are exactly where they survive a move, and nothing is visible from outside.

Check the motor housing and the back panel before anything comes into the kitchen. Look for droppings and egg cases rather than live insects. The same applies to anything from a house clearance, a commercial kitchen or a shared house.

The Building Around You

In a flat, this is usually the whole answer. Risers, ducting, soil stack voids, bin stores and refuse chutes connect every property on a stack, and a treated flat next to an untreated source gets reinfested.

Seal what you can reach: the soil stack boxing, waste pipes under the sink, the extract vent, and the threshold under the front door. Then push the managing agent for a block-wide inspection and attention to the bin store rather than flat-by-flat call-outs.

Make the Property Less Worth Staying In

Fix the water first, because cockroaches need it more urgently than food: a dripping tap, a leaking waste, condensation under an appliance, a wet tray behind the fridge. Then the food residue in the places nobody cleans — under and behind the appliances, inside the kickboard void, in the plinth.

Then reduce the harbourage: seal gaps at kickboards and worktop joins, fill cracks in tiling and plaster, and close the hollow legs and plinths of units where you can.

Keep Monitoring Afterwards

Leave the monitors down for months rather than weeks, and look at them. Cockroaches are built not to be seen, so "we have not seen one" is not evidence of anything and the monitors are.

A single insect caught on a monitor three months later is a small problem caught early — ring then rather than waiting to see whether it happens again. Treatment is £190 for a flat and £240 for a house, and the early version of the job is always the shorter one.