German roaches in a rental: what the tenant does and what the owner has to do

German cockroaches in a rental are a different job than German cockroaches in a single house. In a house, the roaches are yours and the walls are yours. In a duplex, fourplex or apartment building, the roaches move between units through the same gaps the plumbing and wiring use, and the treatment has to move with them. That one fact explains almost every failed roach job we get called back on in Pahrump and Nye County.

Here is what an owner and a tenant each need to understand before anybody sprays anything.

Why treating one unit almost never holds

German cockroaches live inside the structure, not on it. They nest in the void behind a dishwasher, under the lip of a countertop, in the hollow of a hollow-core door, in the motor housing of a refrigerator, in the hinge of a cabinet. Those voids are usually continuous between units. The plumbing chase behind a kitchen sink in one apartment often runs straight into the chase behind the kitchen sink next door, because the units were built back to back to share pipe runs.

So you treat unit A. The population in unit A drops. Meanwhile the population in unit B has never been touched, and it keeps sending roaches down the same chase. Six weeks later unit A looks the way it looked before, and the tenant in unit A is convinced the treatment did not work. It did work. It just did not cover the part of the building where the rest of the roaches lived.

This is why our German cockroach control work in a multi-unit building is scheduled as a building job, not a unit job.

What contact spray does to a shared-wall building

The store-bought can that kills a roach on the counter is the single worst thing you can use in a duplex. Two reasons.

• Roaches avoid surfaces that have been sprayed with a repellent product. They do not die; they leave. They leave through the wall void, which means they leave into the neighboring unit.
• Spraying breaks up the harborage. One tight cluster of roaches in one kitchen becomes four or five small clusters scattered across two apartments, and scattered clusters take far longer to knock down than one concentrated one.

We regularly walk into a building where one tenant has been spraying for a month and the unit next door suddenly has roaches for the first time. The neighbor did nothing wrong. They just got pushed into.

If there are roaches in a rental, the most useful thing a tenant can do is stop spraying and call. Everything after that gets easier.

The prep a tenant is asked to do

Prep matters more in a roach job than in almost any other pest job, because the treatment goes where the roaches actually are and the roaches are in the kitchen and bathroom. A tenant is generally asked to handle this before the appointment:

• Clear the countertops, and empty the cabinets and drawers next to the sink and the stove so the technician can reach the corners and the undersides.
• Bag up food and put it in the refrigerator or in sealed containers, and pull small appliances away from the wall.
• Pull the trash, including anything in a bin under the sink, and take it out of the unit.
• Take out cardboard. Roaches breed in corrugated cardboard, and stacked boxes in a closet are a nest we cannot reach.
• Fix or report a dripping faucet, a leaking trap, or a sweating pipe. Roaches need water more than they need food, and a slow drip will keep a population alive through a good treatment.
• Leave the unit accessible on the follow-up date, because the second and third visits are what finish the job.

Nobody expects a spotless apartment. A German roach problem is not a verdict on housekeeping; these roaches arrive in grocery bags, in used appliances, in moving boxes, and in the wall from next door. What we need is access, not a showroom.

Why the owner has to open the adjoining units

For a building job to work, the units on either side, and the unit above and below where the floors are shared, all need to be inspected and treated in the same window. Not next month. The same visit cycle.

That is the part only the owner or the property manager can arrange, because only they can get the notice out, get the keys, and get every tenant to prep on the same day. A technician cannot knock on a door and let themselves in. If two of six units stay closed, those two units become the reservoir that reinfects the four that were treated, and the whole cycle starts over at the owner's expense.

The same logic applies to buildings that mix housing with a storefront or a shared laundry room. If a rental sits above or behind a business space, that space gets looked at too, and our commercial pest control side handles those. Roaches do not know where the lease line is.

What the schedule actually looks like

A German roach job is a series, not an event. There is an initial treatment, then follow-up visits a couple of weeks apart, because eggs are protected inside a case and hatch after the first treatment is down. The follow-ups catch that next generation. Skipping the second visit is the other common way these jobs fail.

Between visits, the useful work is unglamorous: keep the water off, keep food sealed, get the cardboard out, and leave the treated areas alone rather than scrubbing them down. Tell us what you are still seeing and where, and roughly what time of day. That tells us where the harborage is better than anything else does.

If you own or manage a rental in Pahrump, Nye County, Las Vegas or Spring Valley and you have German roaches in one unit, call us at (775) 469-0919 and we will look at the whole building before anybody treats anything. The estimate is free.