You’ve spotted a concerning problem in your home – cockroaches. Without any delay, you contact your local exterminator for help in eliminating all of them.

Once the professionals inspect your home and apply the appropriate treatment to it, it will take the exterminator between one and four weeks to get rid of the roaches completely.

The specific duration depends on several factors, such as methods, infestation levels, species, and home size all of which we discuss below.


Factors that determine roach treatment duration

As multivariate as cockroaches are, so are the characteristics that’ll play a role in how long you’ll have to contend with the pests. Some include:

Type and number of methods

Ridding your home of roaches for good will require you to go guns blazing with a combination of the most effective pest control treatment methods.

As the University of California Agriculture and Natural Resources found, cockroach treatment ranges from taking 24 hours for a gel bait to two to three weeks for dusts and powders.

Infestation level

Surface-level cockroach infestation often only requires one appointment with a pest control company, which may include the assessment and subsequent pest treatment, all within a day.

For more severe cockroach infestations, however, the pest control professional will need to revisit your home following the initial treatment to monitor the effectiveness of their techniques.

Overall, you could be looking at up to a month of thorough extermination, but at least you won’t need to move into a new apartment.

Wondering how to tell what infestation level you’re facing? Check this guide out.

Species of roach

The particular critter you’re dealing with will determine how long getting them to die will take. This consideration is due to how different cockroach species react to chemical treatments and their distinct life cycles.

For example, in monitoring and controlling German cockroaches, treatments specific to them would be ineffective against brown-banded cockroaches.

Home size

Your home’s square footage is directly proportional to the time and effort pest control professionals need to snap up every last roach.

Cockroaches are fast and adaptable, so a successful treatment may involve applying exterminator sprays in rooms and spaces where you’ve never seen roaches.

What to expect from the extermination process

Critically, spraying insecticides isn’t sufficient to ensure the cockroaches stay gone. Several treatments are often necessary to decisively deal with infestations.

Before the extermination

The pest control professionals will do an initial sweep of your house, gauging the property’s severity and kind of infestation. These factors inform the duration and cost of the exercise and the integrated pest management approach (IPM) they’ll use to rid your space of cockroaches for good.

The pest control technician may set up sticky traps near suspected roach hotspots to give them a better idea of their number and normal habits. They’ll also want to find potential entryways and attractions, which they’ll use to advise you on basic steps you can take to minimize the infestation before fumigation.

During the extermination

Remove any food, dishes, or other sensitive items from your home before the agreed-upon fumigation day. Other preparation strategies may include:

  1. Thorough cleaning of your house.
  2. Taking out the trash, particularly food waste.
  3. Decluttering your space.

Pest control treatments incorporate chemical concoctions that kill roaches but are no better for humans!

A treatment exercise typically takes an hour or two. Afterward, the pest control professionals may ask you to stay out of your house for another half hour so that the concentration of insecticides in your home drops to safe levels.

After the extermination

If you adhere to a multi-faceted IPM, expect to be completely free of your roach problem in a few weeks.

Other measures you should take include:

  1. Leaving the treated areas undisturbed: The pest control professional should have targeted hotspots where they noticed many cockroaches. Avoid cleaning, especially deep cleaning, or otherwise disturbing these areas for up to a week to allow the roach exterminator treatment to work its magic. Light cleaning is all right.
  2. Maintain sanitation and exclusion techniques: Keep food and water supply away from the remaining roaches, and clear up any food debris to further discourage new infestation. Also, keep an eye on known entry points.
  3. Be patient: Even if you see no significant change in the cockroach population a few days after the exterminator’s treatment, yet you’ve been following the pest control advice, give the exercise time. You may require a second treatment or more, adding several weeks to the wait time.

Do roaches get worse after spraying?

It is common to spot more roaches soon after a treatment exercise, but this should assure rather than worry you.

Seeing more cockroaches confirms they’re desperately trying (and failing) to escape the poison. Ordinarily, they’d be in their hiding places. But if they’re in plain view, something is going very badly for them and very well for you.

How to tell if roaches are dying

  1. You spot dead cockroaches: Identifying the location of the carcasses helps you pinpoint the source of the roach infestation, information that’d be useful in case you need to repeat the treatment.
  2. The air smells oily and musty: When these pests die, the decomposition of their bodies releases oleic acid, a moldy stench which is an easy way to confirm that the critters have reduced.
  3. Increased yet stunted roach activity.

Worth noting is how to get rid of dead roaches. Do not touch them with your bare hands. Instead, sweep or vacuum the insects and any lingering body parts, then dispose of them in the trash.

Remove the trash bag containing the cockroaches from your house, as that musty smell attracts live cockroaches.

Why are there baby roaches in my home after spraying?

Baby cockroaches, scientifically called nymphs, hatch from eggs as part of their three-stage life cycle. A German cockroach, for instance, undergoes a 100-day life cycle.

Being encased in the egg within an egg case could have protected the babies against the chemical agents used by the pest control professional.

Therefore, nymph sitings shouldn’t worry you. If they remain exposed to the treatments that eliminated the older cockroaches, the little ones are about to die, too.

Is It Really Worth Hiring an Roach Exterminator?

For a severe infestation, it’s worth to hire a cockroach exterminator. Cockroaches are challenging to eliminate, and the cost of traps and sprays can add up. Investing in professional extermination is worth it for a roach-free living environment.

Can I Just Wait for Winter for the Roaches to Go Away?

Unfortunately, waiting for winter won’t lead to the disappearance of cockroaches. These resilient pests do not retreat during the colder months. Instead, they seek refuge indoors, making proactive pest control measures essential to address the issue effectively.

Scott Williams
Author: Scott Williams - Scott is a pest control expert and has worked in the industry for over 20 years, most recently in NYC, where he runs a pest control business. Scott loves to write articles, share his knowledge on exterminator services, and advise on safe DIY method.