Various smoke-free staircases are now integral elements of modern multi-storey buildings. Why? Because in the event of a sudden fire, they can become the only way to salvation. For structures of such a plan, there is a special classification. And this article describes the features of types H1, H2, H3, which need to be considered in more detail.

The main purpose of all smoke-free cells

The aforementioned staircases are flights of certain dimensions and are located in the most suitable zones of multi-storey buildings. Such structures should serve as emergency exits for people in specific buildings. First of all, we are talking about situations directly related to fires.

After all, significant smoke pollution of the upper space of buildings is a consequence of any fires, regardless of their scale. And many people die in such situations not at all from the flame itself, but from the extremely negative influence of all kinds of toxic fumes and smoke. Therefore, evacuation exits must be isolated from smoke.

However, this is not all. With the help of the stairs, the photos of which can be seen in the article, rescuers have the opportunity to get to the interior of the houses in order to quickly extinguish the fire and take the injured residents outside. These structures even allow people to be carried on stretchers in case of emergency.

Key varieties of unique designs

After watching videos located on different network resources, it becomes clear that all smoke-free cells are divided into three main types:

Standard requirements for such structures

Absolutely all non-smoke staircases must meet one hundred percent of certain mandatory requirements. Basically, they relate to both the dimensions of the entire structures and the dimensions of the marches themselves:

1. The minimum height of the ceilings located in the areas where the marches are located must be at least 190 cm. Only in this way it will be quite convenient for the average person to move along the evacuation routes.
2. Having studied the features of types H1, H2, H3, you can find out that the width of the passages in the so-called "air zones" should reach 120 cm. But the dimensions of the paths leading to them cannot be less than 110 cm, this is really extremely important. Indeed, in this way, completely unimpeded movement of two people and the transfer of victims on a special stretcher is ensured.
3. The steps of the flights of stairs must have the same parameters. As for the slope, it usually does not exceed 40 degrees.
4. A maximum of 18 ordinary steps can be located on one march, this is clearly visible in the photo below.

All kinds of fences made exclusively of non-combustible materials are considered mandatory elements of smoke-free structures. They allow not only to minimize the risk of injury to people, but also greatly facilitate movement.

Useful information about H1 cells

Various specialized videos perfectly demonstrate that in buildings with a height of about 30 m, high-quality smoke-free class H1 structures must be installed. They are directly connected to the floors of buildings. And structures of a similar plan are located precisely in the corners of houses (from the windward side).

These staircases are equipped with balcony-type transitions, which are fenced off with reliable protective screens. Their width cannot be less than 1.2 m. But the dimensions of the walls between such passages must already reach 2 m.

What you need to know about constructions of class H2?

It is noteworthy that smoke-free staircases of the H2 type are mainly settled in buildings, the height of which ranges from 28 to 50 m.The list of their main features includes:

Although in such structures, autonomous air supports from electric pumps are sometimes equipped. These devices are equipped with uninterruptible power supplies. But for this, it is necessary to very carefully calculate the traction force even when designing mandatory ventilation.

Construction of smoke-free structures of the H3 type

Having considered the main features of the types H1, H2, H3, one can understand that the stairwells of the third class are still different from other structures. They are complemented by special areas intended for people to cross, in which self-closing doors with innovative door closers are installed. Their dimensions must be at least 4 square meters. meter, not less.

Separately, it is worth mentioning the air pressure. At such structures, it is carried out not only in the space occupied by the stairs, but also in the existing locks. In addition, the backwater can be turned on automatically during fires, or it can be supplied on a permanent basis.

Materials used for the manufacture of staircases

Modern smoke-free structures, the photos of which are in this article, are created exclusively from materials that can resist heat well and do not ignite in direct contact with fire. For example, these include concrete. It is absolutely fireproof, and flights made from it have increased strength.

Sometimes metals are also used for cells of such a plan. However, these materials are used only in cases where it is simply not possible to build more massive structures. Craftsmen reinforce both the inner parts of the concrete flights and the fences with metal elements. All this is clearly visible in the video.

Why is it worth contacting our specialists?

In order for smoke-free staircases to perform their functions fairly well, they must be made only of the highest quality materials in accordance with all the rules. Using the services of our specialists, customers can easily purchase very beautiful, most reliable, and most importantly, really durable structures in Moscow at the lowest prices.

Experienced craftsmen create such structures in accordance with generally accepted requirements and norms. In addition, they always take into account the wishes of the clients during their work. That is why our designs are extremely popular today.

When erecting stairs in multi-level premises, builders should take into account the fact that in the event of a fire, it is the stepped structure that can become the only way to get out into the air and save people. Depending on how adapted the system is for the evacuation of persons in the building, staircases are usually divided into types H1, H2, L1 and L2. The main design features of these spans, as well as the requirements for them, will be discussed in this article, illustrated with a large number of photos and videos.

Before starting the design of a multi-level building, the architect should pay special attention to the development of sketches of staircases.

What is a staircase

Before the construction of the staircase begins, a special vertical opening is designed in the building for it - a staircase.

A staircase is a collection of all elements of a stepped structure, as well as walls, ceiling, floor, window and door openings

• step marches;
• platforms;
• fences;
• walls with door and window openings;
• floors and floors.

The types of stepped platforms are classified depending on their fire safety and the degree of smoke when a fire occurs

The main criterion by which the stairwells are subdivided into types is fire safety and unhindered evacuation of people in the event of a fire and smoke.

In case of fire, it is the staircase that may be the only way to evacuate people from the building.

Staircase classification

Depending on the level of smoke in the event of a fire, staircases can be:

• ordinary - this type is divided into types L1 and L2;
• smoke-free - types H1, H2 and H3.

Stepped cages can be regular or non-smoke

Ordinary landings

Structures that can be subject to smoke during a fire belong to ordinary staircases, which in turn are divided into two main types - L1 and L2. Next, we will consider them in more detail in the photo.

This drawing schematically shows two types of conventional staircase systems - L1 and L2

Type L1

Stepped platform L1 is characterized by the presence of glazed windows on each floor, located in the load-bearing wall of the building, through which natural light enters the room. In some cases, these openings in the wall may not be glazed.

At each level of the staircase belonging to type L1, there must be glazed window openings

Type L2

The staircase of type L2 has natural lighting, which enters the flight through the glazed openings made in the covering. The photo below clearly demonstrates this type of ordinary staircase.

Type L2 is characterized by the presence of natural light entering the cage through glazed or open wall gaps

Smoke-free staircases

The main requirements for this type of systems are:

• the presence of special locks for the entry of air flows from the smoke-free zone to the stepped cage;
• the presence of evacuation passages that allow people to leave the dangerous room at the time of fire.

Smoke-free structures also have their own subdivision - these are types H1, H2 and H3. Let's analyze them in more detail.

In many multi-storey buildings, smoke-free staircases are used, which are safer for operation in extreme conditions.

Type H1

This type of staircase has an entrance from the floors of the building through the street part of the building along an open passage, free from smoke. This type of construction is often used in administrative, public and educational institutions, whose height exceeds 30 meters. It is considered the most suitable for evacuating people from a building covered in smoke.

A distinctive feature of the H1 stepped cage is the presence of an exit from the stairs directly to the street

H2 type

The H2 platform is distinguished by the presence of a special ventilation backpressure, through which, in the event of a fire, clean air will be supplied to the stairs, which will enable people to receive oxygen. This option is used in rooms with a height of 28 meters. A photo of the construction is presented below.

Type H2 is equipped with a special support for supplying clean air flow in case of fire

Type H3

The smoke-free stepped cage of the H3 type is equipped with an entrance from the floor through the vestibule, as well as oxygen pressurization with the possibility of repeatedly supplying air to people in the event of a fire in the room.

If we are talking about low buildings, then ordinary stairs of the type L1 and L2 are more often used here, in high-rise buildings it is necessary to erect systems related to the types H1, H2 and H3

We examined the main types of stairwells, according to SNiP standards. However, the above classification does not apply to economic stepped structures installed in country houses for the transition between two or three levels.

This photo shows the staircase system, illuminated in a natural way through the windows in the wall, located throughout the entire structure.

Requirements for stairs and stairwells

Since ladder systems in the event of a fire serve evacuation purposes, they must be erected taking into account the norms prescribed by SNiP 21-01-97.

All standards and regulations SNiP 21-01-97 for the staircase cells must be taken into account at the very beginning of construction

According to this regulation, the following requirements are imposed on staircases located inside multi-level buildings:

• 1 m 35 cm - for buildings of class F 1.1;
• 1 m 20 cm - for houses with more than 200 people on each floor;
• 0.7 meters - for ladders designed for a single workplace;
• about 90 cm - in all other cases.

This photo shows schematically three types of smoke-free staircases, according to the requirements for them.

2. The permitted slope of the structure for carrying out evacuation measures is 1: 1.

3. The depth of the tread is at least 25 cm.

4. Step height - no more than 22 cm.

5. The slope for open systems is 2: 1.

According to the standards, the slope for open stairwells is permissible in a ratio of 2: 1

6. Open-type structures must be made of non-combustible materials and mounted near blank walls, class not less than K1 with the highest fire resistance limit. The platforms of such stairs must have a fence with a height of at least 1 m 20 cm.

7. The width of the platform must correspond to the width of the march.

The width of the march should be sufficient for the evacuation of people from the building in the event of a fire or in the event of smoke, this is especially true for children's and school institutions

8. Doors to the cage when opening must not obstruct the march and the landing.

9. It is not allowed to clutter up staircases with cabinets and other equipment.

SNiP norms allow equipping the staircase with special luminous railings

10. The use of luminous railings is allowed.

11. Stairways of the H1 type must have an exit to the outside.

12. Cells of types L1, H1 and H2 should be illuminated with natural light through specialized holes in the facade walls on each floor.

13. Platforms of type H2 are equipped with blind (non-opening) windows.

When building a staircase, it is necessary to take into account all fire safety standards applicable to it.

Related Videos

The video below provides background information on this topic.

Modern high-rise buildings require emergency exits called smoke-free staircases.

This type of evacuation must be provided by the architect even during the development of the building itself. The life of people living in multi-storey buildings largely depends on its presence.

An important condition is that non-smoke stairs must meet the requirements of SNiP, otherwise their presence will be considered as an additional exit, and not an evacuation one.

What are smoke-free staircases for?

The need for houses with a large number of staircase floors that are not prone to smoke is due to the following factors:

• Preventing the death of people during a building fire;
• Possibility of free penetration of fire brigade employees to the fire site;
• Protection of people during the evacuation period from the effects of toxic substances contained in smoke during a fire;
• Providing rescue services with access to any floor of the building in order to save human lives and the possibility of carrying out on a stretcher victims who are not capable of independent movement;
• The opportunity for everyone living in the building will go down from any upper floor to the lower one without prejudice to their own health during the period of necessary evacuation.

There are many options for smoke-free staircases, depending on this, they must meet certain requirements.

Types of smoke-free staircases

Basically, all escape routes in multi-storey buildings are divided into three types depending on their location according to the principles of functioning and accessibility:

• Type H1 - access to the stairs is provided by entering an open area. The output paths must also be of the non-smoke class;
• Typical staircase H2 - this type assumes the presence of an air pressure, the opening of which is necessary in the presence of fire situations;
• A typical staircase Н3 - the design and operation is similar to Н2, the difference is that the air pressure can be used on a permanent basis, and the staircase is accessed through the vestibule - an airlock.

Staircase type H1

A smoke-free staircase of the H1 type is mandatory for use in structures with a height exceeding 30 meters.

The access to this staircase is carried out through the corridor to an open area. This can be an unglazed veranda or a regular balcony, as well as any other area that has a special fence and is located outside the building.

The best option for the location of the stairs H1 is the corner part of the high-rise building. This is interpreted by the need for an isolated outlet from smoke. In addition, the door that leads to the open area must be made of fireproof material.

Staircase type H2

This type of evacuation structure is required in buildings with a height of 28 to 50 meters.

A feature of this structure is that the structure itself is located inside the building. The walls where the smoke-free staircase is located must be made of fire-fighting material.

The door leading to the emergency exit is located directly in the building, therefore, a prerequisite is the presence of a ventilation duct. It is due to his presence that the requirement for air pressure on the stairs is fulfilled.

Basic rules for the operation of smoke-free staircases

Regardless of what types of staircases in your house, the operating rules for all are the same:

• You can never block the passage to the emergency exit;
• It is necessary to monitor the presence of lighting in stairways;
• Periodically check the operation of the ventilation duct (if the escape route belongs to class H2);
• It is important to keep track of the relevance of information on routes leading to an escape route;
• Evacuation passages should not contain any cable channels, except for those provided for fire safety.

SNiP requirements for emergency exits

Not every staircase can be an emergency exit.

It must comply with the requirements of SNiP:

• The width of the emergency passage must be at least 1.2 m;
• Height not less than 1.90 m;
• The number of flights on a stairway between floors should be no more than 15.

The main materials used in the manufacture of smoke-free staircases

In order for the staircase to be truly fireproof, the material of its manufacture plays an important role.

The fact is that it must withstand high temperatures in contact with fire.

Concrete and metal are considered the best options.

Metal structures of staircases are very well suited for building escape routes of the H1 type.

For type H2, it is best to use a concrete structure, since they are not only durable and comfortable, but also always comply with SNiP requirements.

There are times when a tree is used to build a smoke-free staircase, but in this case it must be impregnated with a special solution that prevents fire.

For what characteristics are smoke-free outputs checked by firefighters

It is important to know by what parameters the evacuation routes are checked.

When a multi-storey building is commissioned:

• Compliance with the size of the main parameters;
• Inspection of the integrity of the structure of the structure;
• Assessment of the quality of the protective coating;
• The presence of the integrity of the weld;
• Compliance with the requirements for the placement of a smoke-free staircase;
• Testing the strength of the following structural elements: steps, beam fasteners, platforms, staircase and roof fences.

In addition, once every 5 years, the possibility of using emergency exits is checked according to the following characteristics:

• Checking the integrity of the structure of the structure;
• No cracks in the welds;
• The quality of the protective coating;
• Integrity of ladder girders;

Strength is tested:

1. Steps;
2. Stair railings;
3. Playgrounds;
4. Balcony railings.

All the above described requirements for smoke-free staircases are important to know not only for architects and employees of construction companies, but also for an ordinary person.

Two and three-story mansions should also be equipped with emergency exits.

1. When buying an apartment in a multi-storey building, do not forget to ask about the availability of escape routes;
2. Make sure they are in working order;
3. Conduct a training exercise with all members of your family on the use of escape routes so that at the moment of danger there is no panic (especially if the H2 staircase is used);
4. Make sure that the path to the smoke-free staircase is always open. In cases of its obstruction, contact the perpetrators with a request to remove the obstacle.
5. Only the vigilant attitude of everyone living in a high-rise can help save the lives of hundreds of people.

Today we will again deal with calculations and parameters regarding stair structures. It will be about the cells of the stairs in relation to their fire safety.

What do the requirements of the Sanitary Norms and Rules say about the permissible and unacceptable smoke content of openings, areas of evacuation stairs? What is a smoke-free staircase? Find out. As the proverb says, he who is forewarned is armed.

Staircase types

What are smokeless cages? As is clear from the phrase, these are staircase openings, into which combustion products, in particular smoke, do not get into during a fire. There are three main types of smoke-free cells:

1. Н1 - they get into it from the floor through the outer zone along open corridors. In this case, the crossings should be not subject to smoke.
2. H2 - a platform with an air pressure in case of fire.
3. Н3 - exit into it from the airlock with air pressurization in case of fire or constant air flow.

Evacuation exits from smokeless cages

Doors that lead from such cages are emergency exits and must comply with certain requirements of SNiP 21.01.97 *. They state that the width of the emergency passage cannot be less than 1.2 meters, and the height - less than 1.9 meters. These parameters refer to premises of class A1.1 with more than 15 people evacuated at the same time.

External exits from the cages must be no less than the specified design parameters or no less than the width of the flight of stairs.

Note:

The width of the evacuation opening should make it possible to carry the stretcher with an adult without difficulty.

If the exits from the smokeless cages do not meet the above requirements, they are considered as spare (emergency), which people can use during the evacuation. But they are not initially taken into account as evacuation. These outputs include:

• to the balcony, open both from all sides and from one side;
• to the passage leading to the adjacent section of the building, class F1.3;
• to the balcony / veranda equipped with an external fire escape.

Nuances of smoke-free cells

If such a landing is equipped right next to the wall of the elevator shaft, that is, they have a common wall, then a ventilation hole is made in it at the level of the last floor so that air can freely pass into the shaft.

Type H1

In buildings higher than 30 meters (type A, B and C), according to the regulations, all staircases (category H1) must be smokeless. Each unit must have natural daylight from a window and be fitted with an emergency light source.

Stairwells (type H1) must be equipped in residential and public buildings with a height of its upper floor of more than 30 meters. This type can be characterized by a device that enters it through the vestibule from the corridor or vestibule through an open external air zone along a loggia, balcony, external passage or gallery. The width of the air zone must be at least 1.2 meters, the width of the approach to this zone must be at least 1.1 meters.

The H1 smoke-free staircase can be positioned in the inner corners of buildings. But it is necessary to ensure effective smoke-free air zone (requirements of SNiP 21.1). It must be remembered that the distance between the exits of the staircase and the adjacent window must be at least two meters. As for the width of the wall between the openings in the outer zone of the air supply, it is also allowed at least two meters.

H2 type

According to the requirements of SNiP 31.1, smokeless areas of the H2 and H3 types can be designed in large cities with a top floor height of more than 28 meters and up to 50 meters. The presented types of cells are allowed even with a lower height of the last floor of a public or residential building. Sites of type D and D (simple) should be separated by a blank partition to a height of two spans every thirty meters.

Access to the smoke-free staircase of type H2 can be carried out through the vestibule-gateway, corridor, it is also allowed to pass through the elevator hall, if fire doors of category EI30 are installed in the elevators.

Smoke-free staircases H2 are distinguished by the device for supporting the air flow during fire directly into the staircase itself. It is advisable to delimit them vertically into separate compartments every seven to eight floors in order to reduce the volume in which the air pressure is created. Air support is provided by supplying air to the upper areas of the compartments.