What is an elevator shaft

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Elevators that run through vertical fire compartments must meet the corresponding fire protection requirements. In the case of lift shafts in particular, there is a risk of fire spreading to other floors and usage units.

conditionson elevator systems
According to Section 39 (1) of the Model Building Regulations (MBO), elevators inside buildings must have their own lift shafts in order to prevent the fire from spreading to other floors for a sufficiently long time. If the lift shaft walls are made of flammable building materials, they must be clad on the shaft side with non-flammable building materials in sufficient thickness so that there is no spread of fire on the surfaces of the lift shaft walls when the lift shaft doors are open or closed doors have burned through. This cladding is not identical to the encapsulation of combustible load-bearing and stiffening components (capsule criterion K₂60) according to the model guideline on fire protection requirements for highly fire-retardant components in wood construction (M-HFHHolzR). For a sufficient thickness, depending on the required fire resistance of 30, 60 or 90 minutes, one or more gypsum fiber boards may be necessary.

It must be possible to ventilate the lift shafts and have an opening for smoke evacuation with a free cross-section of at least 2.5% of the lift shaft base area, but at least a size of 0.10 m². The position of the smoke outlet openings must be selected so that the smoke outlet is not impaired by the influence of the wind.

Requirements for landing doors
According to § 39 Paragraph 1 Clause 2 MBO, lift shaft doors and other openings in lift shaft walls with the required fire resistance are to be made in such a way that fire and smoke (fire) cannot be transmitted to other floors for a sufficiently long time.

Lift landing doors must essentially consist of non-combustible building materials. Lift landing doors are regulated construction products. They may be installed without approval provided the manufacturer presents a certificate of conformity from a recognized certification body, which proves that the door does not differ significantly from the technical building regulations (MVV TB1) Part C (C 2.6.2 Lift shaft revolving and folding doors for lifts in lift shafts with walls of fire resistance class F 90) named DIN 180902 / DIN 180913 / DIN 180924 deviates. Annex C 2.6.1 of the MVV TB also applies.

These lift landing doors require a certificate of conformity (ÜZ) according to § 23 MBO.

Lift landing doors with the European classification "E 30/60/90" according to DIN EN 81-58: Safety rules for the construction and installation of lifts - Review and test methods - Part 58: Testing the fire resistance of lift landing doors only meet the requirements of Section 39 (2) sentence 2 MBO1 if

  • the cars are mainly made of non-combustible building materials,
  • the doors are controlled in such a way that they only remain open as long as required to enter or exit the car,
  • the lift shaft has an opening for smoke evacuation.

If several are arranged next to each other, the landing doors must be separated and attached to them by components that have the same fire resistance as the landing wall. The fire behavior of the components of the landing door must be proven; they must be at least normally flammable.

Preventive fire protection assumes that the installation of two regulated elevator doors - one on each floor - in conjunction with the required smoke extraction from the shaft prevents the fire from spreading to other floors for a sufficiently long time (2-door theory).

Fire control
The fire control of an elevator system is intended to prevent the elevator from continuing to be used as a means of transport in the event of a fire or other dangers in a building. A distinction is made between three types of fire control.

Static fire control
With static fire control, the elevator travels directly to a predetermined destination stop (fire stop) by means of a command and stops there with the doors open. The command can be triggered by an existing fire alarm system or just by a single manual call point at the destination stop (fire stop).

Semi-dynamic fire control
In the case of semi-dynamic fire control, at least the specified destination stop (fire stop) is monitored with an automatic fire detector (smoke detector). If this fire alarm has detected smoke, the elevator on the floor above is shut down with the doors open.

Dynamic fire control
The dynamic fire control requires the presence of a fire alarm system according to DIN 146755 ahead. With this, at least all smoke sections in front of the elevators on each floor must be monitored with automatic smoke detectors. This prevents the elevator from stopping and opening its doors when a fire alarm device is triggered in the building on a smoky floor. Instead, the elevator drives to the predetermined destination stop (fire stop), which is usually always on the floor with the shortest secured exit directly to the outside. If a fire alarm device has also responded on this floor, it is stopped on the next smoke-free floor above and the elevator is shut down there with the doors open.

Retrofitting a fire control
If elevator systems no longer meet the current state of the art or the requirements of the industrial safety regulations and are retrofitted, the installation of a fire control must also be reassessed. In buildings that are used by a large number of people and that have a fire alarm system that is connected to the fire brigade, at least one static fire control should be implemented retrospectively. In all other buildings with passenger elevators, a yellow manual call point (RAL 1004) with the label “Fire control elevator” should be installed on the ground floor. When activated, the elevator drives to the entrance floor (fire stop) and remains there with the doors open until someone responsible (caretaker, elevator maintenance service) resets it. It is recommended to use a siren or horn to signal the triggering of the fire control at least on the entrance floor. The corresponding set of rules is DIN EN 81-73 Safety rules for the construction and installation of lifts - Special applications for passenger and freight lifts - Part 73: Behavior of lifts in the event of fire, here especially point 5.8.1 and point 5.7.

Elevators without lift shafts
According to the MBO, elevators without lift shafts are permitted under the following conditions:

  • within a necessary stairwell, except in high-rise buildings
  • within rooms that span floors
  • for connecting storeys that may be openly connected to each other
  • in buildings of building classes 1 and 2

The driving area of ​​these elevators must be clad in such a way that people cannot be endangered. In the past, these casings were mainly designed as wrought-iron lattice shafts; From the 1950s onwards, masonry or concrete shafts were built; today, lift shafts are often made of glass and steel. An opening for smoke evacuation is not required. If necessary, ventilation to dissipate waste heat etc. may be necessary. Since there are no wall quality requirements for the unnecessary lift shaft itself, there are also no requirements for ventilation openings.

1) Sample administrative regulation for technical building regulations (MVV TB) 2019/1
2) DIN 18090: 1997-01 Elevators - Lift shaft revolving and folding doors for lift shafts with walls of fire resistance class F 90
3) DIN 18091: 1993-07 elevators; Shaft sliding doors for lift shafts with walls of fire resistance class F 90
4) DIN 18092: 1992-04 elevators; Vertical sliding doors for small goods lifts in lift shafts with walls of fire resistance class F 90
5) DIN 14675-Series of standards: Fire alarm systems

Expertise on the subject

Basics

Building regulations for standard buildings

The building regulations of the federal state in which they are erected are decisive for the fire protection requirements for structures such as buildings.

Building services systems

smoke extraction

About technical measures that serve to keep escape routes and common areas for people in the event of fire smoke-free or smoke-free and to improve the visibility for the fire brigade.

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Building classes

The requirements for structural fire protection in buildings are measured in the model building regulations and all state building regulations according to the building classes.

Special constructions

Skyscrapers

The model high-rise guideline (MHHR) contains special requirements and solutions for structural and operational, but especially for system-related fire protection.

Special constructions

Wooden structures

Which regulations apply to buildings of GK 4 and 5 that are predominantly made of wood? What should you watch out for with the components, connections and openings used?