Stopping Rats Getting from the Garden into an East London House
Stopping rats getting from the garden into an East London house means closing five routes: defective or redundant drain connections, gaps at pipe and cable entries, broken or missing airbricks, gaps under door thresholds, and the climb from a downpipe into a soffit. Drainage defects are the commonest of the five and the most often missed.
Which route do rats actually use most often?
Defective drainage is the commonest route from outside into a house, and in older terraced streets it is the first thing to rule out. Rats live and travel in sewers. A crack, an open joint, a collapsed section or a redundant branch pipe gives them a way out of the sewer into the ground beneath a building, from where they work upwards through the sub-floor void.
Redundant drains are the specific culprit in East London's Victorian and Georgian terraces. Most of those houses were built with an outside water closet in the rear yard. When the toilet was removed during twentieth-century modernisation, the branch drain that served it was frequently capped at the surface but left connected to the main run below ground. A capped, unused branch is an open sewer pipe with a lid on it.
Another defect does the same job: a broken interceptor trap, the water seal historically fitted between a property's drain and the public sewer, removes the barrier it was built to provide.
What are the above-ground entry routes?
Above ground, rats use four openings: service pipe and cable entries, defective airbricks, gaps beneath door thresholds, and eaves or soffit gaps reached by climbing.
Service entries are the most common of the four. Where a soil pipe, waste pipe, gas service, water main, electricity cable or broadband duct passes through an external wall, the hole is cut oversized and often finished with nothing more than a bead of mastic or a squirt of expanding foam. Both are chewable. Airbricks are the second: they exist to ventilate a suspended timber floor, so they open directly into the sub-floor void, and a cracked clay airbrick or a plastic grille broken by frost is a doorway into exactly the space rats want.
Which routes do people most often discount?
Door thresholds and the climb to the eaves are the two routes people most often discount. Thresholds matter on side and rear doors, particularly where a house has settled or a new floor has been laid without adjusting the door, since rats will gnaw a timber door bottom to widen a gap that is already there.
Rats climb well, and a downpipe, a bin store roof, a boundary wall or the flat roof of a rear extension all give access to the eaves. Open soffit joints, a missing eaves closer or a lifted felt edge then lead into the roof void, which connects to the rest of the house through pipe and cable runs.
How is each entry route fixed, and who is usually responsible?
Each entry route has a physical fix and a normal owner.
| Entry route | The fix | Who is usually responsible |
|---|---|---|
| Defective or collapsed drain | Drain survey, then patch lining, joint repair or excavation | Owner or freeholder up to the boundary; the sewerage undertaker, Thames Water in London, beyond it |
| Redundant capped branch drain | Disconnect and permanently seal at the main run, not at the surface | Owner or freeholder |
| Sewer route into the building | Non-return valve or rat flap, plus repair of the defect that allowed access | Owner or freeholder; a drainage contractor, not a bait programme |
| Pipe and cable entries | Mortar, or expanding metal mesh and steel wool packed behind sealant | Landlord or freeholder as exterior |
| Defective or missing airbrick | Stainless steel or cast airbrick cover; never simply block it, as the floor void needs ventilation | Landlord or freeholder as exterior |
| Gap under a door threshold | Metal threshold strip and a kick plate on the door bottom | Landlord for the structure; tenant for a door they fitted |
| Soffit and eaves gaps | Mesh and eaves closers; remove or guard the climbing route | Landlord or freeholder as roof and exterior |
When is a drain survey the only way to settle it?
A drain survey becomes the only way to settle a rat problem when activity continues after competent treatment and proofing, because the remaining route is then one nobody has seen. A survey pushes a camera through the run from an inspection chamber and produces a recorded report showing joints, cracks, redundant connections and standing water. Five conditions justify one:
- Activity persists after two completed treatment visits and no external burrows or runs were ever found.
- Sightings are confined to the ground floor, particularly in a kitchen with a suspended floor or a boxed-in soil stack.
- A drain smell appears in a downstairs room, a cupboard or a sub-floor void.
Which signs point at the drain run itself rather than the house?
Two of the five conditions that justify a survey point at the drain run itself rather than at the house.
- The house has had a rear extension, a new bathroom or a removed outside toilet, all of which alter or abandon drain runs.
- Neighbours on the same terrace report rats too, which points at a shared run rather than one household.
A survey also establishes who pays, because a defect on the private drain within the boundary is the owner's and a defect in the lateral drain or public sewer beyond it belongs to the sewerage undertaker. Get the report in writing with the camera footage, because it is the document that moves a repair from argument to instruction.
Why will more bait not fix a drainage defect?
More bait will not fix a drainage defect because bait removes the animals currently using the route and does nothing to the route itself. A sewer holds a population that replaces itself, so the household pays for a treatment cycle indefinitely instead of paying once for a repair. That puts a premium on turnaround, because every month before the camera goes down is another cycle bought.
Continuous baiting is also restricted practice. The CRRU UK Code of Best Practice, published by the Campaign for Responsible Rodenticide Use, does not treat permanent baiting as routine: it requires specific justification, a risk assessment and periodic review, because continuous exposure raises non-target wildlife risk and encourages resistance. A permanent drain defect is not a justification for permanent bait; it is a justification for a drainage contractor.
What is the correct sequence of work?
The correct sequence for stopping rats getting from the garden into an East London house is diagnosis first, then physical exclusion of every route the survey has found, and only then treatment of whatever rats remain inside the building. Urgency applies to the diagnosis and not only to the treatment: 247 Pest Control states that same-day attendance is available across London and responds to emergency enquiries 24/7, while noting that attendance time cannot be identical for every call. The survey settles three things: which pest it is, which treatment suits the property, and the soonest the work can be scheduled.
What are a landlord's and freeholder's obligations?
A landlord letting a dwelling on a tenancy of less than seven years must keep in repair the structure and exterior of the property and the installations for the supply of water, gas, electricity, sanitation and drainage. That covers the drain, airbricks, walls, roof and exterior doors — almost every route a rat uses.
Domestic hygiene, pests and refuse is a rated hazard within the Housing Health and Safety Rating System (HHSRS), and a local authority environmental health team assessing a serious hazard can require works. The assessment is of the dwelling, not of the tenant's housekeeping, so a defective airbrick counts against the property however carefully the household stores its food.
In a converted flat the position splits. The lease normally makes the freeholder or management company responsible for the structure, roof, exterior walls, drainage and communal areas, and the leaseholder responsible for the inside of the flat. Where the responsible party will not act, premises in such a state as to be prejudicial to health or a nuisance count as a statutory nuisance, and the local authority has power to serve an abatement notice on the person responsible.
Frequently asked questions
Can rats really come up a toilet?
It happens, and it is a sign of a drainage defect rather than a freak event. Rats swim and can travel a sewer run and a soil stack. A single incident warrants a drain survey, because the route that allowed it is usually a broken interceptor trap, a redundant branch or a damaged run — none of which a treatment closes.
Who pays for a drain repair, me or the water company?
It depends where the defect is. A defect on the private drain within the property boundary is the owner's responsibility, while the lateral drain and public sewer beyond it belong to the sewerage undertaker, Thames Water in London, following the transfer of most private sewers in England to the water companies. A camera survey report identifies which side of the line the defect sits on.
My landlord says the rats are my fault. Where do I stand?
The landlord must keep the structure, exterior and drainage installations of a let dwelling in repair, regardless of who reported the problem or how the household keeps the kitchen. Report in writing, keep dated photographs, and contact the council's environmental health team, which can assess pests as a rated hazard under the Housing Health and Safety Rating System.
Does a rat flap on the drain solve the problem on its own?
Not on its own. A non-return valve, sometimes called a rat flap, blocks the sewer route at the point it is fitted, but it does not repair a cracked run, a redundant branch or a broken chamber, and a badly fitted one can cause blockages. Fit one alongside the repair the survey identifies, not instead of it.
How do I check a firm will actually proof the building rather than just bait it?
Ask for a written proofing schedule before booking, listing each opening, the material to be used and who does the work. The British Pest Control Association (BPCA) publishes Codes of Best Practice covering survey, treatment and proofing. 247 Pest Control works with BPCA-certified technicians across Greater London and offers a No Reinfestation Guarantee, and any competent firm will put its proofing recommendations on paper.
