The shop for professionals – business accounts, volume discounts & more

Encyclopedia

Water column and breathability (reading rain jackets correctly)

The water column states in millimetres how much water pressure a fabric withstands before water gets through. Breathability shows how much water vapour the fabric lets out, which manufacturers usually state in grams per square metre per 24 hours. The standard for rain protective clothing, by contrast, rates water resistance (Wp) and breathability (Ret) in its own classes from 1 to 4. The millimetre and gram figures given by manufacturers are not standard classes.

View matching products

When is this relevant?

Both values help when comparing rain jackets, but they say nothing about workmanship. Taped or welded seams, zips and hoods also decide whether the finished jacket stays waterproof. For high physical exertion, breathability is worth a look so that sweat does not build up under the jacket.

Water column

The water column is stated in millimetres. EN 343:2019, by contrast, calculated in pascals, where 1000 Pa corresponds to about 102 mm of water column. The highest class 4 required at least 20,000 Pa there, which is around 2040 mm. A manufacturer figure of 20,000 mm is therefore a measured value and not equivalent to class 4.

Breathability

Manufacturer figures in grams per square metre per 24 hours are better the higher they are. The standard works with the water vapour resistance Ret, where a low value is better. Both figures describe the same aim but cannot be converted directly.

Examples from the range (manufacturer information)

  • Dassy Kalama: 5,000 mm water column and 5,000 g/m² per 24 hours
  • Schöffel PRO Jedentag: 10,000 mm water column, windproof
  • Schöffel PRO Regenschutz: 10,000 mm and 10,000 g/m² per 24 hours, as a packaway rain jacket
  • Schöffel PRO Regenzeit, Schutzschild and Winterzeit: 20,000 mm and 20,000 g/m² per 24 hours

Seams and workmanship

Water-repellent is not waterproof. According to the manufacturer, the Schöffel PRO Blitzlicht is finished as wind- and water-repellent, the Schöffel PRO Schutzschild has fully taped seams, and the Dassy Minsk and the Dassy Nordix have welded seams.

Sources

  • DIN Media: DIN EN ISO 24232:2026-05, protection against rain
  • Vandeputte Safety Experts: From EN 343 to EN ISO 24232:2025 (04.05.2026)
  • Manufacturer data sheets Hees & Peters and Kübler on EN 343:2019 (class values)
  • Manufacturer information Dassy and Schöffel PRO, accessed on 30.10.2026

Last updated: · This explanation is for general information and does not replace legal advice.