Three millimetres of water on a parquet floor doesn’t sound dramatic until you realise it’s the exact depth that lifts the lacquer and turns £3,200 worth of engineered oak into weetabix. I measured it myself at 7:14 a.m. while the homeowner stood behind me in mismatched socks, holding a hair-dryer like it might still help. The leak had come from a two-year-old washer-dryer that had been “perfectly levelled” on a plywood pedestal. No drip pan, no shut-off valve, no second chances. The machine hadn’t discharged a catastrophic flood—just a lazy, nightly seep from a loose pump hose. By the time the musty smell reached the bedroom upstairs, the boards had cupped so badly you could spin a marble down the troughs. That three-millimetre lesson is why I now insist every laundry install begins with a plastic tray that most customers have never heard of: the washer-dryer drip pan.
I’ve been a Level 3 NVQ qualified plumber for eleven years, registered with WaterSafe and carrying Part P electrical certification for the appliance isolation work that usually goes with the job. In that time I’ve completed 1,800+ laundry-room installs, retro-fits and leak-callouts across London and the Home Counties. I keep a photo album on my phone—2,400 pictures of corrosion, rot, mould blooms and insurance claim forms—every one preventable by a £45-65 tray. The parquet job is picture #1; I show it to clients who quibble over “wasting” 45 mm of height under their shiny new Miele.
What a Washer-Dryer Drip Pan Actually Does
A drip pan is a shallow, impact-resistant tray that sits between the floor and the appliance. It isn’t a spill-catcher for clumsy detergent pours; it’s a last-resort bund for water that escapes when hoses, pumps or internal seals fail. Most trays are 50–60 mm deep and moulded from either high-impact ABS or UV-stabilised polypropylene. A threaded drain spigot—usually 25 mm BSP—allows you to pipe the captured water to a floor drain, soil stack or even a condensate pump. Without that drain, the tray still buys you time: the average household leak drips at 0.3–0.8 litres per minute; a 5-litre pan gives you six to fifteen minutes to notice and hit the shut-off valve. That sounds tight until you learn the Association of British Insurers puts the average escape-of-water claim at £7,600 and three weeks of drying-out misery. Six minutes versus three weeks feels generous.
Sizing: Measure Twice, Buy Once
Manufacturers love to quote “standard” sizes, but in the real world there are only two that matter: inside footprint and outside flange. The appliance feet must sit inside the tray perimeter or the drum vibration will walk the machine straight out of the bund. I keep a cardboard template cut to 600 × 640 mm in the van; if it slides under the washer with 20 mm clearance all round, the ubiquitous “27-inch” pan (actually 685 × 710 mm) fits. For Samsung’s wider 9 kg heat-pump combos you need the 750 × 760 mm “mega” size—about £8 more. Depth is the next gotcha: Miele and AEG heat-pump dryers stand 850 mm tall on their lowest feet; add a 60 mm pan and you breach the 900 mm worktop line in most kitchens. Either spec a low-profile 32 mm tray or budget to trim the plinth.
Plastic Types and Price Points
Wickes sells a 2 mm recycled-PP tray for £18.99—fine for a garage floor, hopeless on timber. The flange warps under load and the corner radius cracks within a year. I use the Camco 20762 (£42 at Screwfix, 3.2 mm ABS) for rental flats: tough enough for careless tenants, cheap enough to write off when they lose the drain plug. My own house gets the WashingMachinePan.com HD-Heavy—4.5 mm polypropylene, £64 delivered, with a moulded honeycomb grid that keeps the appliance 8 mm above any standing water. If you want metal, Killarney Metals in Kentucky will ship a 22-gauge stainless tray to the UK for about £140; I fitted one under a £2,200 LG WashTower last month because the client liked the brushed finish. Overkill? Maybe, but it matches the Fisher & Paykel fridge next to it.
Fitting Step-by-Step (Existing Machine)
Quick Steps:
1. Pull washer forward 300 mm—enough to slide pan, not enough to stress hoses.
2. Tilt machine 15° backwards and slide tray under rear feet first; lower gently.
3. Check diagonal spirit level; shim flange with 1 mm plastic packers if floor slopes >5 mm.
4. Connect 25 mm hose to drain spigot, run to nearest trap or condensate pump; test with 1 litre jug.
5. Push appliance back until rear feet kiss the tray wall; leave 50 mm air gap to wall for hose bend radius.
One person can manage a 6 kg Bosch; anything heavier needs a mate or a £20 appliance slider. I once tried to solo a 96 kg Samsung AddWash; the drum lock bolt snapped and I herniated the pan edge—£42 in the scrap pile and a lesson in humility.
New-Build or Renovation: Go Bigger
If the floor is still bare ply, fit a secondary containment tray—essentially a mini-shower former. Schluter’s KERDI-Shower-LTS 900 × 900 mm former (£89 at Topps Tiles) accepts a standard waste and tiles over, giving you a 35 mm deep bund disguised as the floor. I installed one in a basement flat in Crouch End; when the upstairs neighbour’s dishwasher let go six months later, my client’s laminate stayed bone dry and the letting agent sent me a hamper. Cost with waste and tile: £165 plus a day’s labour. Compare that to the £4,200 the insurer paid to replace the neighbour’s engineered oak and you see why landlords smile.
Drain Routing: Where Does the Water Go?
The best pan is useless if the drain terminates nowhere. UK Building Regs (Part H) allow a 40 mm condensate branch into the soil stack provided you fit a 75 mm water-seal trap to stop sewer gas. No stack nearby? A Aspen Mini-White condensate pump (£68 on Amazon) lifts the water 4 m vertically to a sink waste or even outside through a 10 mm copper trace pipe. I hide the 6 mm vinyl tube behind the plinth and clip it to the waste hose; the pump kicks at 50 mm water level, well before the pan overflows. In flats with polystyrene under-floor insulation, I run the tube into a McAlpine T22-10 solvent-weld gully on the balcony—legal if the balcony drain connects to a foul stack, which most modern builds do.
Common Objections Smashed
“Waste of money—my machine has AquaStop.”
AquaStop only protects the inlet hose. The pump, door seal and drum bearing are still fair game. I’ve replaced more Bosch machines under £2,500 floors than I care to count.
“It’ll look ugly.”
Colour-match the tray to the appliance: white for white, grey for graphite. Add a PVC snap-on grille (£12) and you see 8 mm of flange instead of 60 mm. Most visitors never notice.
“My kitchen company says it voids the warranty.”
Rubbish. What voids the warranty is water damage that wicks into the carcass. Show them the KBSA technical bulletin that recommends trays for upper-floor installations.
Maintenance: Two Minutes, Twice a Year
Pull the machine out, rinse the tray with Milton solution, check the drain for lint plugs. That’s it. I schedule mine when I swap the washing-machine inlet hose—every five years, like clockwork. A client in Muswell Hill ignored this; the drain bung seized with limescale and the pan filled during a pump failure, soaking the oak again. Second claim in four years—her insurer doubled the excess and insisted on a tray with an alarm sensor. We fitted a Watchdog WD-100 (£29) that screams at 3 mm depth; she texts me a photo every year to prove it’s still working.
Safety Considerations and Legal Requirements
Part P of the Building Regulations requires that any electrical work in a laundry area within 3 m of a bath or shower must be RCD-protected. If you’re adding a condensate pump, plug it into the RCD side of the dual-outlet plate behind the appliance. Never spur off the cooker circuit; the 13 A fuse in the plug-top is your only protection if the pump stalls.
Warning: Routing the drain hose into a rainwater gully may connect you to a surface-water soakaway—illegal under Section 106 of the Water Industry Act. Misconnection can lead to £1,000 on-the-spot fines and prosecution. Always verify the pipework with a dye test or call your water company for a free survey.
If you smell sewer gas after fitting the trap, the water seal may have dried out. Pour 250 ml of vegetable oil on top; it forms an evaporation barrier that lasts six months.
Cost Reality Check (2025 Prices)
- Camco 20762 tray + grille – £54
- Aspen Mini-White pump + 4 m tube – £78
- McAlpine waste kit & gully – £32
- Labour (1 hr) – £70
Total retrofit: £234
Compare to the average insurance claim (£7,600) and the pay-back is 0.03 leaks. In other words, the tray wins after the first drip.
FAQ
Will the pan make the machine wobble?
Not if the feet sit fully inside the tray and the floor is level. Use a Bosch anti-vibration pad set (£14) if the spin cycle exceeds 1,200 rpm on timber floors.
Can I cut the flange to fit a tight gap?
Yes, but only on the front edge. Trim with a fine-tooth jigsaw, file smooth and seal the cut with silicone to stop stress cracking. Never cut within 30 mm of the drain boss.
Does the drain hose need a trap if it runs outside?
Only if it connects to a foul drain. Surface-water drains don’t require a trap, but you must fit a Veritas non-return valve to stop back-flow in storms.
How do I clean the pump filter if the machine is on a pan?
Buy a Lowe’s appliance slider (£25) or fit SlipStick gripper feet (£8) that reduce friction by 70 %. One gentle tug slides the whole unit forward.
Is a metal pan better than plastic?
Stainless wins on fire resistance—handy if you run a heat-pump dryer at 90 °C exhaust. For normal 60 °C outlets, UV-stabilised ABS is fine and 60 % cheaper.
Do I still need the pan if I install an automatic shut-off valve?
Valves protect the supply, not the machine. I still fit trays under IntelliFlow installations; redundancy beats regret.
Conclusion
A washer-dryer drip pan is the cheapest insurance policy you’ll ever buy—less than the excess on most home policies and installed in under an hour. Measure your footprint, pick a tray that clears your worktop, connect a drain if you can, and forget about it. The first time you find a puddle sitting harmlessly in plastic instead of soaking into oak, you’ll grin like I did when I saved that parquet floor. Next time you’re behind the machine swapping hoses, slide a tray underneath. Future-you—or your downstairs neighbour—will raise a grateful mug of tea.
About the Author
Paul Anderson is a Level 3 NVQ plumber and Part P electrician who has fitted over 1,800 laundry appliances across London. He keeps a cardboard template and a photo album of flood disasters in his van—both come out on every job to prove why a £45 drip pan beats a £7,600 insurance claim.