The cupboard under a rented kitchen sink should be set up so that nothing touches its floor, so that a leak shows up within a day rather than a fortnight, and so that the stop tap can be reached without unloading anything. That means a lidded plastic tub or two for the cleaning products, a tray under the bottles that drip, and a sheet of kitchen roll or newspaper laid flat as a tell-tale. When water does appear, the repair is the landlord’s job. Your job is to photograph it, report it and keep a record. That’s true on your own, with a partner, or as one of four names on a shared-house tenancy.
Two things shape the layout. In a hard-water area the tap fittings scale up, washers fail and the joints under the sink weep before much else in the flat does, and in most rented kitchens the cupboard has the waste pipe running straight through the middle of it. Everything below is built around those two facts.
What is actually under the sink
Pull everything out once and look. There are usually four things in there: the waste trap (the U-bend under the plughole), the flexible or copper pipes feeding hot and cold to the tap, the stop tap or isolation valves on those pipes, and, if there is a washing machine in the kitchen, its supply valve and waste hose.
Leaks start in two places. The first is the trap and its compression joints, which loosen over time or crack when something heavy gets shoved against them. The second is the tap tails and the isolation valves, which in hard-water areas fur up and drip from the compression nuts. Both start slowly, as a drip every few minutes that is invisible unless the cupboard floor is bare.
Find the stop tap while you are in there. It is either a small brass tap with a wheel or lever on the incoming cold pipe, or the isolation valves with a screwdriver slot on each tail. Turn it once to check it moves. If it’s seized, tell the landlord now, not on the day you need it. In a shared house, make sure everyone knows where it is, because the person who finds the leak is rarely the person who read this.
Nothing on the floor: tubs, a tray and a tell-tale sheet
The single rule is that nothing sits directly on the cupboard floor, because the floor is where water collects, and a chipboard cupboard base swells and stains quickly once it’s wet.
None of this needs buying:
- One lidded plastic tub (an old storage crate) for the cleaning products. It lifts out in one go for cleaning, and if a bottle leaks it leaks into the tub.
- A shallow tray (a baking tray past its best) under the bottles that drip: the descaler, the vinegar, the bleach. In a hard-water flat the descaler gets used often enough that its cap is never quite dry; how to use it on the kettle, tap and shower head is in how to descale a kettle, tap and shower head.
- A sheet of kitchen roll or a page of newspaper laid flat on the cupboard floor, under the trap and under the tap tails. This is the tell-tale, and it’s the one thing worth remembering from this article. Dry paper stays flat and white; a single drip leaves an obvious ring. It costs nothing and it turns a fortnight’s leak into a day’s.
The stop tap stays at the front, reachable without moving the tub. If reaching it means unloading the cupboard, the layout’s wrong.
Photo: Ron Lach via Pexels
What belongs here and what should move
Under the sink is the dampest, most awkward cupboard in the kitchen, and it should hold the things that do not mind that: washing-up liquid refills, surface spray, bleach, descaler, white vinegar, bicarbonate of soda, bin bags, cloths, spare washing-up brushes, and the dustpan if it fits.
What shouldn’t be here: any food, including tins and unopened packets, because a leak or a bottle of bleach going over ruins them; tea towels and paper, because they soak up damp and go musty; anything electrical; and anything used daily, because bending down for it gets old fast. The washing-up liquid in use lives on the side by the sink and only the refill goes in the cupboard.
Once the food is out, the cupboard is about half as full as it was, which is what makes the tell-tale sheet visible and the stop tap reachable. Sorting the rest of the kitchen the same way, by use rather than by what the cupboard was originally for, is in how to organise a small kitchen without buying anything.
Keeping cleaning products in their original bottles
Don’t decant. It’s tempting to put bleach or descaler into a neater bottle, and the NHS guidance on preventing poisoning is clear that you should keep liquid cleaning products and chemicals in their original containers to avoid them being mistaken for drinks. The original bottle has the hazard label, the instructions and the child-resistant cap. A repurposed squash bottle has none of those.
The same page says to store them out of reach of children, ideally in a locked cupboard, and to put safety catches on low cupboards that contain harmful substances such as cleaning products. The cupboard under the sink is the lowest cupboard in the kitchen, so if children visit or live in the flat this is the one that needs the catch. A stick-on or adhesive catch does not need drilling and comes off a rented cupboard without marking it. The tub inside helps too, because a lidded crate is one more step for small hands.
The monthly check and the 30-minute meter test
Once a month, tied to something that already happens monthly such as changing the bed, open the cupboard and look at the tell-tale sheet. Ten seconds. If it is dry and flat, close the door. If it has a ring on it, run a dry finger along the trap joints and the tap tails to find the source, and swap the sheet.
For a leak you can’t see, for example a musty smell or a swollen patch on the cupboard base, Thames Water’s method for a hidden leak works anywhere with a water meter: turn off all water-using appliances and the inside stop valve, then compare two meter readings taken 30 minutes apart. If the meter has moved with everything off, water is going somewhere. Their figures for what that costs are worth knowing: even a small trickle of water can waste up to 200 litres of water per day, and a leaky loo can waste an average of around 400 litres of water a day. On a metered flat that goes on your bill.
When you find water: photograph, report, log
On the day you find a leak, before anything else, take photos with the phone. If you live with other people, whoever finds it takes the photos; don’t wait for the person whose name is first on the tenancy. The wet sheet, the drip on the joint, the swollen base, any damage to what was in the cupboard.
Then put the tub somewhere dry, lay a towel or a washing-up bowl under the drip, and if it is more than a drip, close the stop tap or the isolation valve on that tail.
Then email the landlord or agent, not just a phone call. Say what you found and when, attach the photos, and ask when someone can come. Shelter’s advice on repairs is to report any repairs to your landlord as soon as possible and to keep a record of what you’ve told them and when. Forward the email to yourself with the flat’s address in the subject line so it is easy to find, and put a printed copy into the tenancy folder of the paper filing system, alongside the deposit certificate and the check-in photos. If a dispute over the deposit ever comes up, that dated email is what shows the leak was reported promptly and was not neglect.
Whose repair it is
This part isn’t a grey area, which I was relieved to find. Shelter’s page on repair responsibilities lists the things a landlord is responsible for, and the list includes pipes, sinks, baths and toilets, and plumbing and drains. In their words, your landlord is always responsible even if your tenancy agreement does not say so. A dripping trap, a weeping tap tail, a failed isolation valve and a swollen cupboard base are all the landlord’s to fix.
What is yours: reporting it promptly, not making it worse, and not attempting the plumbing yourself. I wouldn’t touch compression nuts under a rented sink. Overtighten one and crack the trap, and the damage becomes a conversation about whose fault it is, when it could have stayed a conversation about a leak found and reported the same day.
The tub, the tray and the sheet of kitchen roll are the whole system. The same nothing-on-the-floor idea, applied to the rest of the kitchen, is in the organisation section.
