After a Leak: How to Dry a Room Properly (UK Flood Recovery)

First hour: stop the water, get it out

1. Stop the source. Stopcock for mains leaks; isolation valve for appliance leaks.
2. If water is more than a few millimetres deep, lift it with a wet & dry vac. Do not mop — it redistributes rather than removes.
3. Lift carpets if possible. Trapped underlay holds water for weeks and mould starts in 48–72 hours.
4. Open windows for cross-ventilation. Counterintuitive in UK weather, but outdoor air is usually drier than indoor saturated air.

First 48 hours: dehumidify and circulate

Dehumidifiers remove moisture from the air. Air movers (carpet dryers) circulate that air across wet surfaces, accelerating evaporation. One without the other is ~50% effective. Run both.

• For a single bedroom or bathroom, a 20–30L/day dehumidifier is enough
• For a whole-floor flood or significant spill, 40–60L/day commercial unit
• Close windows once the dehumidifier is running — you are dehumidifying the room, not the street
• Empty the bucket at least daily, or run the condensate line into a drain
• Point air movers across the wet surface at a 45° angle (never directly down)

What to save, what to replace

• Plaster: usually salvageable if dried within 72 hours and not showing "blown" hollow spots afterwards
• Skirting and architrave: save if painted side is unaffected; MDF swells and must be replaced
• Laminate flooring: rarely salvageable — it swells at the joints
• Engineered wood: sometimes recoverable with dehumidification if caught early
• Carpet: yes if lifted, washed and dried within 48 hours; no if left saturated
• Underlay: replace. Always. Foam underlay traps water and hides mould

How long should you run equipment?

A typical single-room domestic leak needs a 30L dehumidifier + one air mover for 3–5 days. A whole-floor event needs 5–7 days with commercial equipment. The test: when wall and floor surfaces feel room-temperature (not cool) to the touch, moisture has equalised. A moisture meter gives a definitive reading (below 16% for wall plaster = dry).

Renting a dehumidifier and air mover together from DIY Toolshare usually costs £40–£60/day — significantly cheaper than a professional restoration callout, and adequate for domestic leaks caught early.