The short answer: for typical water damage in a home, usually one to three weeks. The honest answer: it depends on how much water went where, how long it sat there and what the walls and floors are made of. That's why we take readings on day one – after that we can give a reliable estimate.
What determines the time
- Amount of water and how long it stood: a brief burst dries faster than a leak that ran unnoticed for days.
- Materials: gypsum plaster and plasterboard release water fairly quickly; thick walls and screed far more slowly.
- Insulation under the screed: if water has got into the insulation layer, room drying alone is often not enough – it then needs insulation-layer drying.
- Temperature: warm air holds more moisture. In winter, heaters noticeably speed things up.
- Closed rooms: dehumidifiers work best with doors and windows shut.
A Mallorca speciality: natural stone
Many fincas have thick walls of marès or rubble stone. These walls store a lot of water and release it only slowly. Without technical drying this can take months – with dehumidifiers and heat it's much faster, but still not a matter of a few days.
Typical times at a glance
| Situation | Typical time with a dehumidifier |
|---|---|
| Minor damage, one room, found quickly | approx. 1 week |
| Several rooms, walls and floor soaked | approx. 2–3 weeks |
| Water in the insulation layer or thick stone walls | 3 weeks or more |
| Fresh cement screed (new build) | Rule of thumb: approx. 1 week per cm up to 4 cm, considerably longer beyond that |
These are experience-based figures, not a guarantee. The readings are what counts.
How to tell it's dry
Not by feel and not by the surface – that often seems dry after a few days while it's still wet inside. We measure at fixed points and compare against a dry reference area in the same house. Only once the readings get there do we take the units away. For screed, the CM test decides before any flooring goes down.
Better to stop early?
Better not. If you paint, tile or lay parquet too soon, residual moisture can later cause mould, stains or lifting floors. An extra week of drying is almost always cheaper than the repairs afterwards.