Which doors should be kept closed?

Fire and smoke protection doors are subject to strict requirements

Functional unit of door and wall

Fire doors with a variety of looks: stainless steel sheet, metal tube frame with glass insert, wood decor. Photos: Teckentrup (left, Hörmann (center. Novoferm (right

This proof of conformity is, so to speak, a document with which the installation company guarantees that it has installed the door in compliance with the approval and in accordance with the applicable standards. This is so important because a functional fire protection closure cannot be created simply by installing a specific door. Instead, it always depends on the functional unit of door and wall. On the one hand, fire doors are viewed as a unit of door leaf, door frame and door fittings anyway. These components must therefore all come from the same manufacturer and are also tested by DIBt as a complete system. On the other hand, the approvals for fire door systems also stipulate in a binding manner in which type of walls the respective door may be installed. This particularly concerns the material and the thickness of the walls as well as the execution of the wall connections to the door. Minimum thicknesses are prescribed for concrete, masonry stone or drywall - depending on the performance of the fire door. That also makes sense, because what use is a T90 door, for example, if the adjacent wall is so thin that it would collapse after just 30 minutes of exposure to a flame? In some cases, certain wall constructions are completely excluded from the approvals for fire doors. For example, wooden stud walls are usually only approved for areas in which the installation of T30 doors is intended. However, they must not be used for doors from T60.

What are smoke protection doors?

Fire doors are intended to delay the spread of flames, but they are not necessarily smoke-proof. However, the state building regulations require that corridors, for example, must have a smoke protection seal at least every 30 m; in high-rise buildings, a minimum distance of 20 m is even required. So-called smoke protection doors are available to meet such regulations. These must be able to delay the spread of smoke in the building so long that the protected rooms can be entered without breathing masks to rescue people for up to ten minutes after the outbreak of fire.

The doors are provided with smoke protection by circumferential seals between the door leaf and the frame. In the floor area, the protective effect is achieved, for example, by lowerable floor seals. However, the doors are only smoke-tight and do not meet any defined fire resistance requirements. In contrast to fire protection doors, smoke protection doors do not require a building inspection approval from the DIBt, but only a general building inspection test certificate according to DIN 18 095 and a declaration of conformity from the manufacturer.

The manufacturer can have the test certificate issued by a test center recognized by the DIBt. During the test, a defined fire situation is used to determine the amount of smoke the door lets through (“leak rate”). In the case of single-leaf doors, a maximum of 20 m3 of smoke per hour may reach the other side of the door so that the door can be recognized as a smoke protection door. For double-leaf doors, the maximum permissible value is 30 m3 per hour. Just like fire protection doors, smoke protection doors are self-closing locks that may only remain open permanently if there is a hold-open system approved by the building authorities.

Trend towards multifunctional doors

As mentioned above, fire doors are not necessarily smoke-tight. However, they can also be equipped as smoke protection doors, whereby this must then be proven by an additional test in accordance with DIN 18 095. Many manufacturers offer such products with a double benefit. And what's more: the trend in recent years has increasingly been towards so-called multifunctional doors. These often not only offer fire and smoke protection at the same time, but also a high level of noise and burglary protection.

About the author Roland Grimm has been a freelance journalist based in Essen since February 2013 and regularly writes specialist articles for Building material knowledge. Before that, he was a specialist editor at the industry magazine for around six years Building materials market and also editor-in-chief and, from 2010, editor-in-chief of the trade journal building materials practice. Contact: freelance [email protected]

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