Rats
What Lies Under a Childs Hill Terrace
The borough-wide picture is that most Barnet rats travel above ground along brooks and gardens. Childs Hill is one of the exceptions, and the reason is under your feet. A terraced street of this age was usually drained by clay pipes laid in short lengths, each joint a potential weak point. Tree roots, settlement and the weight of traffic on Finchley Road and Cricklewood Lane all work on those joints over the decades.
Cracked joints and open connections
A rat does not need a collapsed pipe. A joint that has shifted by a centimetre or two, or an old branch left open when a sink or outside toilet was taken out, is enough. From there it can dig through the soil under a suspended floor, and the first you know of it is scratching under the boards at night or a smell in the cupboard where the waste pipe goes down. The guide on how rats get into homes sets out the other routes to rule out.
The interceptor trap
Many older properties have an inspection chamber near the front boundary with an interceptor trap in it, built to stop sewer gases and vermin coming back up. It has a small rodding arm closed by a stopper. When that stopper is lost or breaks, as they often do over time, there is an open path from the public sewer straight into the house drain. It is one of the first things a drainage contractor will look at.
Who Owns Which Length of Drain
This matters in Childs Hill because so many drains are shared. In England, since October 2011, sewers that serve more than one property and lateral drains running outside your boundary have generally been the water company's to maintain, and in this part of London that is Thames Water. The length that serves only your property, inside your boundary, is normally yours. In a mansion block, the drains serving the building are usually handled through the managing agent as part of the common parts, so tell them as well as us.
Signs Worth Checking in an Older Property
- Scratching beneath the ground floor or basement floor, often after the house has gone quiet
- A damp, sour smell around the base of a boxed-in soil pipe
- Droppings in the lightwell, around a gully or next to the inspection chamber cover
- A missing or broken cover on a chamber in the front garden or basement area
- Soil pushed up at the edge of a patio above the line of the drain
The guide to the first signs of rats describes droppings and marks in more detail. If the droppings are small and the noise is in the walls and ceilings of an upper flat, it is more likely mice in the building.
What to Do Before the Visit
- Do not pour anything down the drain to kill rats, which will not reach them and can damage the pipe
- Do not lift floorboards or open a chamber to look for them; note where the noise is instead
- Put the plug in baths and basins in a basement flat overnight and keep toilet lids down
- If a chamber cover is broken, tell whoever owns that length of drain so it can be replaced
When you book
When you book rat control, say whether it is a house or a flat, which floor, whether there is a basement or lightwell, and where you hear or see activity. If you know where the inspection chambers are, mention it.
After the visit
You will be told what was found and what should happen next, including whether a drainage contractor is needed. How long it takes depends on the building and how the rats are getting in, and what affects the timing is explained in the guide. Get back in touch if scratching returns after a quiet spell. Why rats come back is almost always about a route that is still open.
Closing the Drain Route for Good
If a faulty drain is the cause, the lasting fix is a repair or a one-way valve fitted by a drainage contractor, after a survey has found the fault. Gaps above ground, such as a hole around a waste pipe where it enters the house, can be sealed with rodent proofing in Childs Hill. For the brook corridors that drive rats in the rest of the borough, see Rat Control Barnet; for the wider building picture, Pest Control Childs Hill.
