In accordance with fire safety requirements established in Russia, every high-rise building, both residential and non-residential industrial or commercial premises must be equipped with emergency staircase. Any situation with threat to human life, requires immediate safe evacuation to a safe distance. Each floor should have escape routes and exits, which in any case, are not cluttered with extraneous items.
The types of fire stairs
The fire escape must pass through all floors and out on the roof of the building. Each fire stair is manufactured to stringent requirements defined by the standards of the Main Directorate of State Fire Fighting Service.
Evacuation stairs are of two types: external and internal.
External fire escape
It is located outside the building in a place where it can be reached from any floor, and goes to the roof. Most of all they are made of steel. Supporting structure is made of metal pipes and beams, steel profiles. The railing is made of reinforced steel. The stages of PVL, PRN. This avoids the accumulation of snow and debris on the steps, ice. There must be anti-corrosion treatment design.
Internal fire stairs
Steel or concrete stairs must exactly match installed fire safety requirements. It does not necessarily goes on the roof, but connects all floors of the building, from the top to the first floor.
Finish should be non-combustible materials, which will release toxic substances at high temperatures.
The design also should not be afraid of fire – that’s why metal or concrete is used.
Banned forms for use
Regulations strictly forbid the exploitation of the evacuation staircase of the following forms:
- With dancing steps.
- With unequal height or width of the tread.
Structurally, the external evacuation stairs are of the following types:
- On the stringers. Stringers are durable metal beams, located under the steps. The stringer is the carrier element of the whole structure.
- With the joists. Steps are mounted between the two parallel beams.
- On the bowstrings. The string is a side part to which steps are mounted.
- Spiral is characterized by a spiral arrangement of steps. It can be manufactured with the central pillar, and without it. It is used relatively infrequently.
- Frameless on the rails. The carrier element is the wall itself, which is attached to the steel steps on one side, and on the other they are connected to each other by rails.
- Concrete is usually used inside the building. It is structurally different from the metal on strings.
The parameters of the staircase
After you have chosen the form of a ladder, you need to determine its parameters: the quantity of the marches, the width of the steps, size of stairwells, whether it will go up to the roof structure.
The width of a march is usually 90-120 cm. Each march may not be more than 18 degrees. Marches are separated by landings. Steps may be frieze (top and bottom ones which are adjacent to the staircases) and intermediate.
Material of steps
The type of fabrication steps depends on how many the fire escape will weigh itself, as well as the safety of movement of people, icing steps, corrosion resistance and many other critical parameters.
- Steel expanded metal sheet is a lightweight version of regular rolled steel. The mass of perforation is from 70 to 80% less than solid sheet metal. PVL is the best choice for fire escape. Thanks to the lattice structure, steps do not accumulate debris, snow, puddles – stairs are self-cleaning.
- Pressmaster PRN – lattice structure of the steel. Long supporting steel strips are cinched with short connecting elements by cold pressing.
- Concrete steps are used in the construction of the internal fire stairs.
Industrially produced PVL is usually equipped with special anti-skid teeth. This feature along with the lattice structure of the whole structure is particularly relevant in our country where most regions are characterized by complex climatic conditions.
Stairs, railings and banisters
Material for the landing is most often a corrugated sheet. Functionally it is not different from PVL and PNL, which are used for the manufacture of treads, and looks aesthetically appealing.
Railings consist of a handrail which runs parallel to the staircase. The railings are attached to the main staircase with vertical balusters. The space between the balusters is filled on the basis of the design concept of the stairs or can be completely free. The main condition – all materials must be fire resistant, fireproof.
Be especially careful and meticulous in choosing the fire escape, because it may save the life of people in the building. Please contact the staff. Find out more about such structures, in particular, about the trials of fire escapes. Amateur and carelessness in security issues can be very costly in case of emergency.