Bed bugs in a tenement flat: can they come through the walls?

Most people in Glasgow live in flats, and a lot of those flats are in sandstone tenements: four storeys, two or three flats a landing, a common close and stair. If you have bed bugs in a flat like that, the first question after “how do I get rid of them?” is usually “did they come from next door, and will they go back there?”

Do bed bugs really go through walls?

They do not chew or burrow. A bed bug is a flat insect about the size of an apple pip when fully grown, and much smaller when young, and it crawls. What it is very good at is squeezing into narrow gaps. Anything as thin as a bank card will do.

A tenement wall is solid, but the building around it is full of gaps:

• Floor voids. Timber floorboards sit on joists, with an open space underneath that runs across the flat and sometimes under the partition walls.
• Pipe and cable runs. Every flat has water, gas, heating and electrics coming through floors and walls, usually close to the stair. The holes are rarely sealed tight.
• Skirting and cornice. Old lath and plaster walls shrink and crack, and skirting boards pull away. Behind both there is a gap all round the room.
• Shared risers. In ex-council blocks and modern flats, services run up through shared shafts with access panels in each flat.

So the honest answer is: not through the stone, but round it, and quite easily.

Why they move between flats

Bed bugs stay close to where people sleep. They move further when something pushes them:

• the infestation grows and the best hiding places near the bed fill up;
• someone sprays the bedroom with a shop insecticide or a fogger, which tends to scatter them;
• the flat is left empty for a while, so they wander looking for a meal;
• furniture is moved out, down the close, or into another room.

That is why an infestation in one flat sometimes turns up next door a few weeks after the first flat started treating it.

Signs it came from a neighbour

None of these prove it, but they point that way:

• The first bites or spots appear on the side of the bed nearest the wall you share, or near the pipes.
• You find bugs or spots along the skirting or round a radiator pipe before you find them in the mattress.
• A neighbour has mentioned bites, or a mattress has been dumped in the back court recently.
• You have had a treatment that worked, and a few months later the bites are back.

What to do in a close

Talk to the neighbours

It feels awkward, but it saves everyone money. Most people with bed bugs are relieved to hear they are not the only ones. Keep it practical: you have found them, you are getting a treatment, and it would help if they checked too.

Use the factor or the landlord

If the close has a property factor, tell them. They can pass a note round without naming you. If you rent, tell your landlord or letting agent in writing; they may own or manage other flats in the stair. Housing association tenants should report it to the association.

Ask for the flats around yours to be looked at

When the technician comes, ask whether they can check the flat across the landing and the ones above and below, if the people living there agree. Many do it at the same visit for a small extra charge. Treating the neighbours at the same time costs less than treating your own flat twice.

Seal the gaps after treatment

Once the treatment is done, filling the gaps round pipes and along the skirting with a flexible sealant makes it harder for anything to come back the same way. It is not a treatment in itself, but it helps.

Does it change the treatment?

It changes the plan more than the method. Both spray and heat work in a tenement flat. What matters is that the treatment covers the routes in, not just the bed. A careful technician will:

• treat or check along the shared walls, skirting and pipe runs;
• often apply a residual product at those points after a heat treatment, so bugs arriving later meet it;
• ask about the neighbours and suggest a check visit a few weeks later.

If you are comparing options, our Glasgow bed bug treatment page sets out what to do first, who pays when you rent, and typical prices for spray and heat.

If you rent

In Scotland, a private landlord has to keep the home meeting the Repairing Standard, which includes being reasonably fit to live in. Where bed bugs are moving between flats in a building the landlord owns or manages, that is firmly their problem to sort. Report it in writing, keep a copy, and give access for the treatment. This is a general guide; your tenancy and the facts of your case matter.

What not to do

• Do not use foggers or shop sprays in the bedroom. They are a common reason bed bugs end up next door.
• Do not move to the couch or a different room to sleep. They follow you.
• Do not carry an unwrapped mattress down the stair. Wrap it in plastic first, and book a bulk uplift rather than leaving it in the back court.