Wasp Nests Under Roof Tiles – A Common Problem for Edlington Homes

Wasps do not need a big opening to get into a roof, and understanding the gaps they use explains why nests turn up under tiles so often.

A queen needs only a small gap

A wasp is a surprisingly small insect, and a queen emerging in spring is smaller than most people imagine. A gap that looks negligible to a person may be a doorway to her. She is looking for somewhere dry, sheltered and out of sight where she can build the first few cells, and a roof offers plenty of choice.

Roofs are made of overlapping pieces, and wherever pieces meet there is a potential gap. Over the years, weather, movement and age make small gaps larger. Mortar crumbles, pointing cracks, tiles shift a few millimetres and timber shrinks. None of this makes the roof unsafe, but together it provides a number of invitations.

It also helps to remember that wasps do not make holes in sound masonry or well-fitted tiles. They use what is already there, so a roof in good order is much less attractive, although never entirely immune.

The usual points of entry

Queens and workers tend to favour a handful of spots. If you walk round the outside of your house, look at these places from the ground:

• Beneath the edge of the tiles. The overhang at the bottom of the roof, where the first row meets the gutter, often has gaps.
• The ridge. Mortar or fixings along the top of the roof can crack and open up.
• The verge. The sloping edge at the end of a gable is another place where tiles and wall meet imperfectly.
• Soffits and fascias. Small holes, gaps at joints or where boards have warped.
• Vents and flashings. Roof vents, chimney surrounds and the junction with an extension all create joints.

You do not need to climb to check them. Binoculars or a phone zoom from the garden are enough to notice crumbling, dark gaps or a line of insects.

When you check, take notes rather than trying to remember. A simple sketch of the house with crosses where you see wasps entering is a perfectly good way to pass the information on.

Do not worry if the gap you notice is only a hairline. A queen can squeeze through openings that look entirely harmless, and it is the repeated traffic that gives the game away, not the size of the hole.

Why the underside of the tiles is so appealing

Once inside, a queen finds ideal conditions. The space beneath the tiles is dry and shaded, and the felt or underlay gives her a surface to attach to. In some roofs there is a continuous run of cavity from the eaves to the ridge, which lets a nest develop out of sight and gives the colony more room to expand.

This is also why nests can grow to a good size before anyone notices. They are hidden behind the covering of the roof, and sound is dampened. The first sign is often wasps seen around a window or a light, or a line of insects at an outside gap. By then, the colony may have been there for weeks.

Remember that wasps start nesting in early April in a typical year, depending on the weather. Colonies grow all summer and peak in August, when a nest can hold as many as 2,000 wasps.

The ridge and the eaves are linked in many roofs, so wasps that enter at the bottom can travel upwards inside, and a nest that seems to be near the gutter can in fact be much higher.

What you can and cannot do about it

Spotting the gap is useful, but it is not an invitation to repair it while the nest is active. Wasps need to come and go, and a blocked entrance pushes them to other routes, often inside the building. Wait until the nest has been treated and the wasps have stopped flying before repairing anything.

In the meantime, stay off ladders and roofs. If a nest is under tiles, the safest thing is to leave it alone, keep the nearby area clear and arrange treatment. You can describe the gap you think they are using and take a note of which part of the roof it is on.

If you are unsure whether it is wasps at all, say so. Sometimes insects around the roofline turn out to be bees or something else, and the technician will tell you honestly what the situation is.

When the time comes to repair, use the material a roofer recommends for your roof type, and think about ventilation, since some gaps are there on purpose and should not be blocked completely.

If you find several possible gaps, list them from the ground and pass the list to the roofer afterwards. A systematic repair is far better than a patch here and there, and it costs little extra if done in one visit.

Treatment and booking

Treating a nest is £70 per nest, and a second nest on the same property is £25 extra. There is no call-out charge. The price is confirmed on the phone before the technician visits. For a nest high on the roof that needs special access equipment, the price might be higher, and you would be told before agreeing to anything.

Technicians are fully insured and qualified and work seven days a week. Same-day service is offered for homes and businesses. In Edlington and the neighbouring villages, you can book through the form or the contact page, and the technician is notified by SMS and email.

Once the nest has been treated, ask about the empty nest if you want it taken down, and plan the repair of the gap with a roofer. That keeps next year’s queen from choosing the same opening.

Frequently asked questions

More wasp advice for Edlington