Wasp Nest in a Cavity Wall – How Professionals Treat Hidden Nests in Kirk Sandall

It seems logical to plug the hole wasps use to get into a wall, but closing an active entrance usually sends the colony somewhere worse.

The instinct to plug it

You spot wasps entering a small hole in the wall of your house and the response comes naturally: seal it up. A tube of filler, a wad of newspaper, a bit of expanding foam. Problem solved, you think, and for a few hours it may even seem that way.

The trouble is that the wasps inside do not disappear. A nest that has been growing since early April, and which may by late summer hold as many as 2,000 wasps, has workers coming and going all day. When their route is blocked they do not give up. They look for another way, and the colony inside keeps developing.

For a homeowner in Kirk Sandall, north-east of Doncaster, this advice is worth keeping in mind before reaching for the filler.

There is nothing foolish about wanting to stop it. The mistake is understandable because blocking gaps is the right idea in autumn and winter, when the nest is empty. It is just the wrong idea when the colony is still living behind it.

What happens behind a blocked entrance

Wasps are good at finding alternative routes. A cavity has many small gaps, such as around pipework, wiring, window frames, vents and the junction between the wall and the roof. If one exit is shut, some will move along the cavity until they find another, and the traffic simply appears elsewhere on the outside of the building.

Others may follow warmth and light. If the inside surface of the wall has any opening, that is where they emerge. Many people report wasps in a bedroom, behind a curtain or beside a light fitting a day or two after plugging the hole outside. A blocked entrance also makes the wasps agitated, which makes them more likely to sting.

If wasps do appear indoors, close the door to the room and cover the gap at the bottom with a towel. Open a window in the room to let them leave, and keep everyone, including pets, out of that space until the visit.

Foam and filler also make the later treatment harder to plan, because the original entrance is hidden. If you can scrape away a plug safely after the wasps have gone, leave that for the repair stage.

A few other things not to do

• Do not spray insecticide into the hole. It rarely reaches the nest, and it can drive wasps out into the room.
• Do not try to burn, smoke or flood the entrance.
• Do not stand directly below the hole or leave a window open next to it.
• Do not break into the wall to look. You may open a route directly into the house.
• Do not leave food and drink out near the entrance.

If you have already blocked the hole, don't panic. Leave it, keep your distance, and tell the technician exactly what you used and when. It is a very common mistake and professionals can work around it.

Think too about the neighbouring garden. Wasps blocked on your side of the wall may head out towards next door, and it is only sensible to give them a quiet word if you notice the activity moving.

What actually works

A trained technician treats the nest itself, rather than just the wasps at the door. Working from the entry point where practical, they deal with the colony so that the workers have nothing to return to. The technicians at The Wasp Exterminator are fully insured and qualified, and the work is described as safe and effective.

Sealing comes later. Once the technician is satisfied that activity has ended, the gap can be repaired, which is the stage at which closing the hole makes sense. Do this too early, and you are back at the original problem.

When the technician arrives, they will ask where the wasps were entering, what has been done already and whether any have reached the inside. They may ask the household to stay indoors, keep windows closed or move a car away from the wall. Following these instructions makes the visit quicker and safer.

Cost, speed and booking

There is no sliding scale based on nest size. A single nest costs £70 per nest, a second at the same property is £25 on top, and no call-out charge applies. The figure is agreed over the phone before the technician visits and no work goes ahead without your agreement. Where the nest sits in a spot needing special access equipment, the price might be higher, and you would be told in advance.

The business is open seven days a week and can offer same-day service to domestic and commercial customers. Ring 07798 792 774, or fill in the online booking form or contact page, and the local technician is alerted by SMS and email.

Pets and children should be kept away during the visit, and the technician will say how long the area needs to be left alone.

If a neighbour shares the wall or boundary, a quick word is also courteous, so they are not surprised to see a technician. Whether you need their agreement for any work is something to check for yourself.

Repairing the wall properly

Once the wasps have gone, ask a builder or confident DIYer to fill the gap properly. Raking out loose mortar and repointing is better than a quick dab of filler, and a damaged air brick grille should be replaced rather than blocked, since it is there to provide ventilation.

If your home is rented, report the gap to your landlord and look at your tenancy agreement to see how repairs are handled. Do the repair before next April, when queens start looking for suitable places.

A good repair is worth the effort, because a wall that is neatly pointed is much less likely to attract a queen the following spring.

Frequently asked questions

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