Smoke tightness Smoke tightness EN 13501-2; EN 1634-3 : Sa, Sm (200°C)

Although this performance feature is not yet mandatory in most national legislation, we recommend adding smoke tightness to the requirements intended to protect your building.

Experience shows that if fire breaks out, (toxic) fumes are the element that causes most losses:
Human loss Material loss Collateral damage throughout the building


Smoke tightness (S) is a performance feature covered by European standard EN 1634-3 which may be added to fire-resistant doors (EN 1634-1).

Heinen can protect you from smoke thanks to its tests carried out for the Sa index (smoke at ambient temperature) and the Sm index (hot smoke at a temperature of up to 200°C).

At Heinen, we can combine this protection on fire-resistant doors, as well as on Metal+ doors, with acoustic protection, burglary resistance, etc.

Standards table

European standards EN 13501-2
EN 1634-3
Symbols S
Resistance class Sa
>Sm (200°C)
Smoke tightness performance featureResistance class
>Sm (200°C)

European standards EN 13501-2; EN 1634-3 : Sa, Sm (200°C)

Smoke tightness S is the ability of the component to reduce or eliminate the transmission of gas or smoke from one side of the door to the other. The following performance levels are defined:

The Sa index relates to smoke tightness at ambient temperature only.
The Sm index relates to smoke tightness at ambient temperature and at 200°C.

In the case of fire-resistant components, S must be added to the fire-resistance classification (e.g. EI2 60 – Sm).

  • Smoke tightness Sm – when the maximum flow rate measured at one of the temperatures (ambient and 200°C) and up to a pressure of 50 Pa does not exceed 20 m³/h for a single-leaf door set or 30 m³/h for a double-leaf door set.
  • Smoke tightness Sa – when the maximum flow rate measured at ambient temperature and at a pressure of less than or equal to 25 Pa only does not exceed 3m³/h per metre of clearance between the fixed and mobile components of the door set.

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