How does rain affect a pest spray?
Updated: Apr 9
This is perhaps the most common question we get asked about our pest control treatments and it’s a good one! At Spiderman SE we always have one eye on the weather channel as we need to take the weather conditions into account at the time of spraying. Both rain and wind can impact whether we can safely carry out a spray and it can also impact the long term performance of the treatment. Here’s why…
Firstly, it’s important to understand how insecticide sprays work. When we do a treatment we obviously target any pests we see and when they get hit with the spray they die. However, the aim of a pest spray is to leave an insecticide residue on the surface to provide long-lasting protection from pests. To achieve this, the spray needs to dry and bind to the surface.
The insecticide needs to "stick" to the surface
To bind effectively to the surface, the surface needs to be dry. This ensures we can get the required dose to stick to the surface – with a previously wet surface most of the treatment will runoff. At Spiderman SE we only use premium products that contain additional “sticking” agents to help with this binding property and ensures it delivers long-lasting protection. As the treatment dries, the insecticide binds to the surface and becomes resistant to wash-off in showers.
The bottom line: So as long as the surface isn’t wet and it’s not raining at the time of application, once the treatment is dry the insecticide will be resistant to wash-off in showers, providing long term protection.
Insects like to hide in sheltered areas
Certainly, over time, the insecticide in areas that are most exposed to rain and sun will degrade quicker, but the reality is that these are not the areas where pests hang out. Insects and spiders prefer shady, sheltered areas with hiding places to protect themselves from the elements and predators, areas which include under eaves, around doors and windows, and in vents and weep holes. In these areas, our treatments will last for many months, as they are protected from rain and sun – lasting protection just where you need it!
Safety considerations in rain and wind
Safety is always our number one priority with any pest treatment and the weather impacts whether we can spray safely. Even if we are super careful, when the wind picks up it can blow the spray into off-target areas, where it could have unintended effects. Indeed, we are not allowed to spray when the wind gets above a certain speed. Additionally, rain during an application or immediately after can wash the insecticide treatment off the surface taking it into an unintended area or worse still into the drains. So apart from the performance issue that results from spraying in the rain, there are very real safety and environmental considerations as well.
So if we do need to postpone a job if it’s raining or very windy, we hope you understand. A bit of inconvenience is worth it, to ensure we provide a safe service that doesn’t unnecessarily impact the environment. Of course, when you’re paying for a service you want the treatment to last for as long as possible, so it’s best to wait for the rain to pass.