Fire and gas tightness

What do you need to consider?

Fire

Fire protection classes prescribe fire protection properties of different types of construction products. Fire-rated articles shall, by design and choice of materials, prevent fire spread and slow down temperature increases.

The basic requirements for safety in the event of a fire can be found in the Swedish Planning and Building Act, PBL. The law applies to all types of construction works, i.e. buildings or other facilities. The law is interpreted and clarified in Boverket's building regulations, BBR.

For fire doors, in addition to the usual fire resistance classes E, I, W – followed by time indication – there are also additional classes as the requirements are based on where the fire door is located.

A fundamental principle is that it is always the door as a whole – including frame and accessories – that is given a fire classification. Therefore, following the recommended combinations of door and accessories and the manufacturer's installation instructions is a prerequisite for achieving the fire safety requirements.

Another basic principle is that the fire door should have the same classification as the fire cell boundary it is placed in. According to these guidelines, a door mounted in a wall with class EI 60 must have the EI 60 rating. However, several parameters in terms of the building's occupancy class (occupancy class – Vk – 1-6 are specified in BBR 5:21) and Building class affects the classification requirement.

Fire safety in a building is a legal requirement and it is the developer's responsibility to choose fire-rated products as well as to ensure that proper fire protection documentation is made.

Building class affects fire requirements

A building is divided into building classes based on the established need for protection. The assessment of safety needs takes into account the likely course of fire, the possible consequences of a fire and the complexity of the building (e.g. number of floors and the occupancy classes in the building).

Br0 – Buildings with a very high need for protection

• Buildings with more than 16 floors
• Hospitals and other healthcare environments
• Larger public meeting rooms

Br1 - Buildings with a high need for protection

• Buildings with 3-16 floors
• Buildings with 2 floors if the room is used for e.g. hotels, care facilities, school/preschool or places of assembly

Br2 - Buildings with a moderate need for protection

• Detached houses with a maximum of 3 floors
• Lower residential buildings with operations requiring right fire protection (BBR 5:22)

Br3 - Buildings with little need for protection

• Other buildings

The activities in the premises determine the fire classification

A building's spaces are divided into several different occupancy classes (Vk). The classification is based on a number of factors such as fire risk, the degree of activity, the ability to put oneself to safety and knowledge of the premises among those staying in the building.

A building can contain several occupancy classes but can only belong to one building class. A school building that includes both school and preschool is classified in building class Br2 but contains separate occupancy classes for school and preschool.

There are a total of 6 occupancy classes.

Vk1: Industrial, offices

Spaces where people are expected to be awake, have good knowledge of building layout and conditions to put themselves to safety.

Vk2: Places of assembly, parking garages

Premises where people are expected to be awake, have the conditions to put themselves to safety, but cannot be expected to have good knowledge of building layout.

Vk3: Dwellings

Spaces where people are expected to have good knowledge of building layout, have the conditions to put themselves to safety, but cannot always be expected to be awake.

Vk4: Hotels

Premises where people have the conditions to put themselves to safety but are not expected to have good knowledge of building layout or always be awake.

Vk5: Healthcare environments

Environments where people have limited or no conditions to put themselves to safety.

Vk6: High fire risk

Premises with a high risk of fire and where a fire can have a rapid and extensive progression.

Fire classes

The fire resistance of a door is based on three main classes, E, I and W, which are always followed by a time indication in minutes.

E stands for integrity against fire and is a tightness requirement that fire in the form of flames does not get through the construction. The E requirement must always be met and can be used as an independent class, for example E 30.

I stands for insulation and is a requirement for maximum temperature rise on the non-fire-exposed side of 140 C° and a maximum of 180 C° at single points. The I requirement is always combined with the E-requirement and cannot be used independently. The European fire door standard has two variants I1 and I2, depending on where the temperature is measured during testing. I1 is a slightly tougher requirement than I2 depending on measurement points near the frame. Since the building regulations in Sweden accept both I1 and I2, the indices 1 or 2 are usually not stated, but only large I's, such as EI 60.

W stands for limiting radiation at a distance of about one meter from the door on the non-fire side. W is always combined with the E-requirement and cannot be used independently. It also cannot be combined with I as W is automatically fulfilled if I is fulfilled. For example, the class EW 60 is available but not EIW 60 as it is included by EI 60.

The same door can have different classes depending on when each function fails. For example, a door in a test can get the result EI 30, EW 60, E 90. It is then up to door manufacturers whether they want to declare all classes or only choose the one that they consider suitable to market for a particular use.

The specified time interval – 30, 60, 90, 120 or 160 minutes – is determined by building and occupancy class.

Fire gas safety

The spread of toxic fire gases is the most common cause of death in connection with fire incidents. A fire door must therefore have the necessary sealing properties to prevent smoke leakage.

The smoke leakage S shows the door's ability to reduce fire gas and smoke leakage from one side of the door to the other at different temperature and pressure conditions. S_a regulates cold flue gases, S₂₀₀ hot fire gases (200^oC). The class is determined by where the door is mounted. 

Class S_a

Class S_a regulates cold flue gases. Class S_a requirements are generally available for the escape route, such as hotel room doors facing a corridor, and are a requirement tested with smoke at room temperature.

Class S₂₀₀

Class S₂₀₀ regulates hot fire gases (200°C). Class S₂₀₀ requirements are available for escape routes to stairwells, such as apartment doors, and tested with medium-hot smoke. If the door meets class S_200, it also meets the requirements for class S_a.

Door closers

In some spaces/facilities, the fire door is provided with a self-closing function. The self-closing function is marked with an additional class with the designation C0 to C5 where C0 stands for no fixed use and C5 for very frequent use.