Cantilever steps. Console ladder - theory, practice from the user of the portal

Cantilever ladders are one of a kind functional elements interior, capable of giving it lightness and modern look while keeping free space in room. main feature any such staircase consists not only directly in the configuration, but also in the specific type of fastening of the steps that do not have an explicit support. They lack traditional variations of kosour or hybrid vertical supports characteristic of screw structures. Cantilever stair treads are open on all sides. They seem to float in the air as steps emerge from the wall.

Our company is engaged in the manufacture of console stairs in Moscow and other cities of Russia.

The benefits that you will receive by contacting us:

• professional designers and craftsmen;
• great experience;
• quality assurance;
• strict deadlines;
• free visit to the object;
• broad consultations;
• a large selection of modern materials;
• individual approach;
• favorable prices.

Fill out the form below and our specialists will contact you as soon as possible, provide a large number of examples of work performed and provide professional advice on issues related to the manufacture of modern stairs.

The feeling of lightness is created by attaching only one part of the steps to hidden supports, and handrails mounted to the wall are used as railings. That's why cantilever ladders may appear unsafe in the photo. However, a more correct design of such a structure completely eliminates the risk of its destruction, ensuring the safety of each family member.

In general, cantilever ladders, in contrast to traditional designs, have the following advantages:

• take up a minimum of space, so they do not clutter up the space for visits;
• do not block light and air flows in the room;
• have stylish attractive appearance being able to join as the highlight of any living room;
• differ in acceptable cost, which is realized due to the small amount of materials for their manufacture.

But, like any other interior items, console stairs have not only positive, but also some negative qualities:

• require the most durable fasteners;
• difficult to design and install;
• less safe than traditional stairs due to the absence of double-sided railings (at the request of the customer, railings can be installed on the free side of the steps).

However, with a professional approach, all these disadvantages can be leveled, which makes cantilever stairs suitable for any cottages and duplex apartments.

Cantilever staircase manufacturing

For the production of cantilever stairs, a wide variety of materials are used today, including.

• Metal. Such designs are not very popular, since, due to the nature of the material, it is quite difficult to fit them into the most common interior styles. However, the console metal ladder can be an excellent solution for a high-tech or loft interior.
• MDF and wood. These are the most common materials for the manufacture of cantilever stair treads, which is primarily due to the universal interior qualities of the materials. The cantilever ladder made of wood will perfectly fit into any interior.
• Plastic. Only the most durable types of plastic can be used. But most often it is used only for finishing tread degrees.
• Glass. Strained glass- This is a fairly popular material for the manufacture of steps for cantilever stairs. Such structures look almost weightless, but they need additional strengthening.
• Concrete. A cantilever concrete staircase is quite complex in design and implementation, since it requires reinforcement of each individual element.

In addition to the directly visible, any cantilever ladder has a part of the structure hidden from the eyes, which ensures its reliable fixation. This structural element is made of metal in the form of channels and brackets, as well as anchor bolts.

There are several basic ways of attaching cantilever ladders. Among them:

• Wall. The steps cut directly into the wall to a depth of 40 centimeters, depending on the material of the staircase.
• Kosour. A staircase on a metal stringer looks complicated in execution welded structure and, as a rule, it is used in cases where the steps cannot be cut into the wall. Also, such designs can be found under the name cantilever ladder on the side stringer.
• Bolts that connect the free part of the treads, thereby transferring the load to each subsequent element, until they are fixed to the floor or ceiling.
• Ropes that act as additional support, at the same time replacing the handrails. IN this case the load from the free side of the steps is transferred to the ceiling slab.
• Profile. Enough reliable option cantilever ladder structures with common features with a stringer. In this case, the steps are fixed to the profile, which is then closed with finishing materials.

As for the cost, the price of a cantilever ladder depends on a number of factors, including the materials of production and the type of fastening, as well as the height of the structure and other conditions.

The norms of this section establish the limiting deflections and displacements of the bearing and enclosing structures of buildings and structures when calculating according to the second group of limiting states, regardless of the building materials used.

The norms do not apply to hydraulic structures, transport, nuclear power plants, as well as supports of overhead power lines, open switchgears and antenna communication structures.

GENERAL INSTRUCTIONS

10.1. When calculating building structures for deflections (deflections) and displacements, the condition must be met

where f is the deflection (deflection) and displacement of the structural element (or the structure as a whole), determined taking into account the factors affecting their values, in accordance with paragraphs. 1-3 of Recommended Appendix 6;

f u - ultimate deflection (deflection) and displacement established by these standards.

The calculation must be made based on the following requirements:

a) technological (ensuring the conditions for normal operation of technological and material handling equipment, instrumentation, etc.);

b) structural (ensuring the integrity of adjacent structural elements and their joints, ensuring the specified slopes);

c) physiological (prevention harmful effects and feelings of discomfort during vibrations);

d) aesthetic and psychological (providing favorable impressions from the appearance of structures, preventing the feeling of danger).

Each of these requirements must be fulfilled in the calculation independently of the others.

Structural vibration limits should be set in accordance with regulatory documents p. 4 of the recommended annex 6.

10.2. The design situations for which deflections and displacements should be determined, the corresponding loads, as well as the requirements for building lifting, are given in clause 5 of the recommended one.

10.3. Limit deflections of structural elements of coatings and floors, limited based on technological, structural and physiological requirements, should be counted from the bent axis corresponding to the state of the element at the time of application of the load, from which the deflection is calculated, and limited based on aesthetic and psychological requirements - from a straight line connecting supports of these elements (see also clause 7 of the recommended annex 6).

10.4. The deflections of structural elements are not limited based on aesthetic and psychological requirements, if they do not impair the appearance of the structures (for example, membrane coverings, inclined canopies, structures with a sagging or raised lower chord) or if the structural elements are hidden from view. Deflections are not limited based on the specified requirements and for structures of floors and coverings over rooms with a short stay of people (for example, transformer substations, attics).

Note. For all types of coatings, the integrity of the roofing carpet should be ensured, as a rule, by constructive measures (for example, the use of expansion joints, the creation of continuity of the covering elements), and not by increasing the rigidity of the bearing elements.

10.5. The load safety factor for all considered loads and the dynamic factor for loads from forklifts, electric vehicles, bridge and overhead cranes should be taken equal to one.

The reliability factors for liability must be taken in accordance with the mandatory Appendix 7.

10.6. For structural elements of buildings and structures, the limiting deflections and displacements of which are not stipulated by this and other regulatory documents, vertical and horizontal deflections and displacements from constant, long-term and short-term loads should not exceed 1/150 of the span or 1/75 of the console's departure.

VERTICAL LIMIT DEFINITIONS OF STRUCTURAL ELEMENTS

10.7. Vertical limiting deflections of structural elements and loads, from which deflections should be determined, are given in table. 19. Requirements for the gaps between adjacent elements are given in clause 6 of the recommended appendix 6.

Table 19

The designations adopted in table. nineteen:

l - design span of a structural element;

a - the step of the beams or trusses to which the overhead crane tracks are attached.

Notes: 1. For a console, instead of l, its double overhang should be taken.

2. For intermediate values ​​of l in pos. 2, and the ultimate deflections should be determined by linear interpolation, taking into account the requirements of clause 7 of the recommended annex 6.

3. In pos. 2, and the numbers indicated in brackets should be taken at a height of rooms up to 6 m inclusive.

4. Features of calculating deflections according to pos. 2, d are specified in clause 8 of the recommended Appendix 6.

5. When limiting deflections by aesthetic and psychological requirements, it is allowed to span l equal to the distance between the inner surfaces of the bearing walls (or columns).

10.8. Distance (clearance) from the top point of the overhead crane trolley to the bottom point of the bent load-bearing structures coatings (or items attached to them) must be at least 100 mm.

10.9. The deflections of the coating elements must be such that, despite their presence, a roof slope of at least 1/200 in one of the directions is provided (except for cases specified in other regulatory documents).

10.10. The limiting deflections of floor elements (beams, crossbars, slabs), stairs, balconies, loggias, premises of residential and public buildings, as well as household premises of industrial buildings, based on physiological requirements, should be determined by the formula

(26)

where g is the acceleration of gravity;

p is the normative value of the load from people exciting vibrations, taken according to table. twenty;

p 1 - reduced standard value of the load on the floors, taken according to table. 3 and 20;

q is the normative value of the load from the weight of the calculated element and the structures resting on it;

n - the frequency of application of the load when walking a person, taken from the table. twenty;

b - coefficient taken according to table. twenty.

Table 20

The designations adopted in table. twenty:

Q is the weight of one person, taken equal to 0.8 kN (80 kgf);

a - coefficient taken equal to 1.0 for elements calculated according to the beam scheme, 0.5 - in other cases (for example, when the slabs are supported on three or four sides);

a - spacing of beams, crossbars, width of slabs (decking), m;

l - design span of a structural element, m.

Deflections should be determined from the sum of the loads y A1 p + p 1 + q, where y A1 is a coefficient determined by formula (1).

HORIZONTAL LIMITS OF COLUMNS AND BRAKE STRUCTURES FROM CRANE LOADS

10.11. Horizontal limiting deflections of the columns of buildings equipped with bridge cranes, crane trestles, as well as beams of crane tracks and brake structures (beams or trusses), should be taken according to Table. 21, but not less than 6 mm.

The deflections should be checked at the level of the head of the crane rails from the braking forces of the trolley of one crane, directed across the crane track, without taking into account the inclination of the foundations.

Table 21

The designations adopted in table. 21:

h is the height from the top of the foundation to the head of the crane rail (for single-storey buildings and covered and open crane trestles) or the distance from the axis of the ceiling crossbar to the head of the crane rail (for the upper floors of multi-storey buildings);

l - design span of a structural element (beam).

10.12. The horizontal limiting approach of the crane tracks of open overpasses from horizontal and eccentrically applied vertical loads from one crane (excluding the tilt of the foundations), limited based on technological requirements, should be taken equal to 20 mm.

HORIZONTAL LIMIT DISPLACEMENT AND DEFLECTIONS OF FRAME BUILDINGS, INDIVIDUAL ELEMENTS OF CONSTRUCTIONS AND SUPPORTS OF CONVEYOR GALLERIES FROM WIND LOAD, FOUNDATION ROLL AND TEMPERATURE CLIMATE EFFECTS

10.13. The horizontal limiting movements of frame buildings, limited based on design requirements (ensuring the integrity of filling the frame with walls, partitions, window and door elements), are given in Table. 22. Instructions for determining displacements are given in clause 9 of the recommended Appendix 6.

10.14. Horizontal movements of frame buildings should be determined, as a rule, taking into account the tilt (rotation) of the foundations. In this case, the loads from the weight of equipment, furniture, people, stored materials and products should be taken into account only when all floors of multi-storey buildings are uniformly loaded with these loads (taking into account their reduction depending on the number of floors), except for cases in which, under the conditions of normal operation other loading is provided.

The inclination of the foundations should be determined taking into account the wind load, taken at the rate of 30% of the standard value.

For buildings with a height of up to 40 m (and supports of conveyor galleries of any height) located in wind regions I-IV, the roll of the foundations caused by the wind load may not be taken into account.

Table 22

The designations adopted in table. 22:

h is the height of multi-storey buildings, equal to the distance from the top of the foundation to the axis of the roof girder;

h s - floor height in one-story buildings, equal to the distance from the top of the foundation to the bottom roof structures; in multi-storey buildings: for bottom floor- equal to the distance from the top of the foundation to the axis of the crossbar; for other floors - equal to the distance between the axes of adjacent crossbars.

Notes: 1. For intermediate values ​​of h s (according to pos. 3), the horizontal limit displacements should be determined by linear interpolation.

2. For the upper floors of multi-storey buildings designed with the use of cover elements of one-storey buildings, the horizontal limiting displacements should be taken the same as for one-storey buildings. In this case, the height of the upper floor h s is taken from the axis of the interfloor crossbar overlapped to the bottom of the rafter structures.

3. Compliant fastenings include fastenings of walls or partitions to the frame that do not prevent the frame from moving (without transferring forces to the walls or partitions that can cause damage to structural elements); to rigid - fasteners that prevent mutual displacements of the frame, walls or partitions.

4. For single-storey buildings with curtain walls (as well as in the absence of hard disk coverings) and multi-storey stacks, the maximum displacements are allowed to be increased by 30% (but not more than h s / 150).

10.15. Horizontal movements of frameless buildings from wind loads are not limited if their walls, partitions and connecting elements are designed for strength and crack resistance.

10.16. Horizontal limiting deflections of racks and crossbars of half-timbered, as well as hinged wall panels from wind loads, limited based on design requirements, should be taken equal to l / 200, where l is the design span of racks or panels.

10.17. The horizontal limiting deflections of the supports of conveyor galleries from wind loads, limited based on technological requirements, should be taken equal to h / 250, where h is the height of the supports from the top of the foundation to the bottom of the trusses or beams.

10.18. Horizontal limiting deflections of columns (pillars) of frame buildings from temperature climatic and shrinkage effects should be taken equal to:

h s / 150 - for walls and partitions made of bricks, gypsum concrete, reinforced concrete and hinged panels,

h s / 200 - for walls lined with natural stone, made of ceramic blocks, made of glass (stained-glass windows), where h s is the floor height, and for one-story buildings with bridge cranes - the height from the top of the foundation to the bottom of the crane runway beams.

In this case, temperature effects should be taken without taking into account daily fluctuations in outdoor temperatures and temperature differences from solar radiation.

When determining horizontal deflections from temperature climatic and shrinkage effects, their values ​​should not be summed up with deflections from wind loads and from the heel of foundations.

LIMITING DEFINITIONS OF ELEMENTS OF INTERFLOOR FLOORS FROM THE FORCES OF PRE-COMPRESSION

10.19. Limit deflections f u of elements of interfloor floors, limited on the basis of design requirements, should be taken equal to 15 mm at l £ 3 m and 40 mm - at l ³ 12 m (for intermediate values ​​l, limit deflections should be determined by linear interpolation).

The bends f should be determined from the pre-compression forces, the dead weight of the floor elements and the weight of the floor.

Modern staircases are less and less simple bulky structures. Instead of them, real design works flaunt in the houses. See for yourself with our inspiring selection of photos. Perhaps you will find here an option that fits perfectly into the interior of your home.

Types of wooden stairs

In order to choose a structure that will harmoniously fit into the space, we suggest that you familiarize yourself with the main types of wooden stairs for the home.

Marching staircase- this is the classic and the most simple construction, consisting of separate marches - straight or turning. True, mid-flight stairs are rarely completely made of wood. Often their base is made of concrete, and the railings and steps are wooden.

Cantilever ladder looks more original, and its design gives the impression of "floating in the air". Such stairs have no massive railings, no static base. The steps are attached to the load-bearing wall with anchors, which ensures their strength and absolute operational safety.

Spiral staircase allows you to save space, it fits perfectly into small room... But it should be remembered that in operation this is not the most convenient option... When installing a spiral staircase, it is recommended to choose a strong handrail, as well as a rough surface of the steps. If space permits, elements of flights can be included in its design: this will provide a more comfortable and safe use of the stairs.

Spinal stairs but consists of separate elements connected to each other. This construction resembles a puzzle and can be assembled in almost any shape. Visually, such a staircase looks light and airy, while being comfortable, durable and reliable.

Ideas for decorating wooden stairs in the house

Having decided on the type of wooden staircase, we suggest that you familiarize yourself with the most interesting design options.

Such a staircase performs two functions at once - it connects the first and second floors, and is also the main focus in the design of the room. Its massive base is harmoniously complemented wooden elements simple geometry, additional safety is provided by a glass fence, which, however, does not take on the main visual accent.

This staircase will ideally complement the interior, made in the style of classicism. Its main highlight is carved details, combined with other elements of furniture and decor. Such stairs are made of noble wood species - cherry, wenge, santal, teak and others.

Original and lightweight, this staircase will become a real highlight of the room. Its main advantage is its compactness and visual weightlessness. And the steps located in checkerboard, turn this everyday element of the interior into a source of pride for design craftsmanship.

Lightweight and modern design This model of stairs is characterized by rhythm, which is further enhanced by the repeating geometric contour of the enclosing element.

This staircase looks simple and modest, but this is its charm. It will fit perfectly into the classically decorated interior, it can be made in different color solutions... It looks good both as a natural and only slightly polished surface, and covered with transparent varnish.

The "broken" staircase will emphasize the originality of the design approach, and will also save the space of the room. Looks good in dark colors contrasting with light walls interior.

An original and bold solution for creative people. The supporting structure of the staircase is made in the form of a tree trunk. The curved lines of the railing mimic branches, and all this is combined with massive, wide wooden steps.

A spiral staircase not only saves useful area, but also gives the room lightness. Looks especially impressive in combination with forged elements that dilute favorably wooden steps and provide additional structural strength.

Such a staircase will undoubtedly become the main element of the room. Such a bold option will suit spacious interiors. It is important that the surrounding space is sufficiently bright and well-lit, this will relieve the room from an oppressive feeling and favorably emphasize its main accent.

This spiral staircase is hassle-free. Stable steps with a fairly wide step and a smooth bend will make descents and ascents along it almost invisible. The light wood looks harmoniously with the snow-white supporting structure, which, in combination with the glass railing, makes the staircase a welcome guest in rooms decorated in a minimalist style.

This staircase will be a bold addition to the interior, furnished with the latest design art. The operation of such a beauty will require certain skills and accuracy. Main advantages- space saving and creativity of execution.

Stable, safe and beautiful design stairs will be the perfect addition to almost any interior. In this case, the main accent is a combination of white and mahogany shades. This technique allows you to emphasize the contours of the stairs and blend in with other wooden objects in the house.

Another classic version... Thin carved railings add airiness to the staircase. The main element here is a carpet runner, emphasizing the status of the owners and helping to make the use of the stairs as comfortable and safe as possible.

A low staircase leading to an additional floor can not only fulfill its main function, but also have a pleasant bonus: pull-out shelves for storing rarely used things.

In the space under the stairs can be placed drawers, shelves with doors and open niches different forms and sizes.

Often, whole corners are placed under the stairs. For example, workplace will look quite organic here. Such a technique will save precious meters and allow more rational use of the vacated space.

This multifunctional ladder will keep children from getting bored. The built-in slide for outdoor games will become the favorite entertainment of the little ones.

Using such a ladder will require some skill. But with it you don't have to worry about saving space, and it will also fit into almost any modern interior.

A full-fledged staircase in the house can be a variation on the stepladder theme. This design somewhat limits the possibilities of its operation. For example, not suitable for families with small children or elderly people. Otherwise, it is practical and quite convenient to use.

A staircase can also be a way for owners to express themselves creatively. By placing beautiful pictures, motivating inscriptions on its steps, or simply painting it in your favorite colors, you can create a unique design accent that allows you to emphasize the beauty of the space and demonstrate your self.

There are a lot of options for stairs for the house. The main thing is to find among them exactly the one that will harmoniously fit into the interior and will give its owners maximum comfort and aesthetic pleasure.

Stylish trends in interior design are increasingly influencing the modification of staircase structures. So, console ladders are gaining popularity. Its advantage is that it does not interfere with the propagation of light inside the room. This design looks quite non-standard, one might even say bizarre. The treads simply hang in the air on the consoles lowered from the ceiling. But you should not be afraid to walk on it, because the design is well thought out. If you have building experience and desire, you can make a comfortable and unusual console ladder with your own hands.

Design features

Design advantages:

• unusual appearance;
• small consumption of material - such stairs do not have risers, and sometimes fences;
• saving space.

It is important when designing such a structure to take into account the loads perceived by the tread.... They have to withstand 150 kg. - and this figure does not include the weight of the handrails.

Even organizations that manufacture cantilever ladders do not have ready-to-install products. They have only individual elements, from which the march will be assembled later. Each design must be developed individually for the customer, taking into account all conditions.

But making such a ladder is quite difficult. Its installation takes place even at the construction stage or before finishing the premises. There are several ways to attach treads:

1. Sealing the steps into the wall.
2. Embedment of brackets into the enclosing structure, on which the treads will subsequently be attached.
3. Fastening steps with anchors.
4. Ceiling mount.
5. Brackets that are welded or screwed onto a steel bowstring.

If the house is made of bricks or heavy blocks, good option for the device of a cantilever staircase, the steps will be sealed at the construction stage. To do this, the ends of the treads must be embedded in the wall at a distance of 1/4 of finished product... So, if you want to make a flight of stairs equal to 80 cm, then you need to lay 20 cm steps. Another requirement for this installation option is that the tread must be pressed down with at least ten rows of masonry.

In the case of using lighter building materials such as porous ceramic, hollow expanded clay concrete blocks or a slot brick, the depth of the treads will increase by 1.5-2 times and will be 30-40 cm. It will be difficult to implement if the thickness of the projected wall is less than required.

Aerated concrete buildings also have their own characteristics of the device of a cantilever staircase. In the walls, it will be necessary to strengthen the sealing points of all treads with the help of embedded elements made of heavy concrete. At the same time, you should not be afraid for the appearance, because there are decorative overlays eg wooden. Laminated panels, natural or artificial stone are also suitable. When using this construction in style solution loft, you can leave everything unchanged.

With this option for installing a cantilever ladder, a profile pipe no more than a meter long must be bricked into the wall. The depth of the bookmark should be at least 25-30 centimeters. The outlets left should correspond to 2/3 of the tread length. The requirements for the walls remain the same, the choice of material for the steps is expanding. For this mounting option, you can use an engineering solid wood, as well as materials based on a wood composite, such as chipboard, MOR. This is because the treads now do not act as self-supporting structures. All the load is transferred to the brackets embedded in the wall. Metal parts can be hidden in grooves or holes that are drilled in treads.

Anchoring

This method is used when the walls have already been erected and it is not possible to embed it into a finished enclosing structure. fasteners as in the first two cases. But the material also remains important. Walls made of porous block or slotted bricks are unable to support the anchors.

To reduce the possibility of pulling out anchors in the event that the walls are not made of sufficiently strong material, it is necessary to greatly increase the size of the support pads.

In order to carry out such an installation of a cantilever ladder, you will need welded brackets with support pads. The finished elements must be attached to the wall at the location of the steps using anchor bolts. Their number should be at least four, and the length should be from 15 cm, while the radius must be chosen more than 10 cm.

Ceiling mount

This method will be an alternative for those whose house has already been built or if the strength of the enclosing walls is insufficient to withstand the load. The fastening of the steps must be carried out before starting finishing works... To briefly describe the essence of this method, it consists in using a powerful welded metal frame made of a channel, also suitable shaped tube... This design is carried out to the full height of the room, because it is attached metal carcass will be towards the ceiling.

The metal frame is placed along the entire length of the march close to the wall. It also needs to be snapped to the top and bottom floors. After that, it is necessary to weld cantilever supports for treads to the resulting racks, it is possible to use fastening bolts. The resulting frame can be hidden with plasterboard sheathing or lightweight masonry.

Steel bowstring

This method of mounting a cantilever ladder is perhaps the most difficult.... Brackets are used for it, which are welded or screwed to a steel bowstring. This support is the only one. It must be fixed to the floors using powerful support pads and anchors. To prevent twisting of the bowstring under load, it is necessary to create a complex structure. It will have welded trusses with stiffening ribs, which are located transversely, diagonally and longitudinally. This design is a bit like the jibs of a tower crane. The console also has some work to do. It must be thought out in order to avoid the unsteadiness of the steps, provided that it is not embedded in the wall.

Strengthening the structure

If you are in doubt about the safe operation and reliability of your cantilever ladder, there are some engineering tricks you can use to strengthen the structure:

• Rigid binding of treads to each other. Bolts are suitable for this. They will transfer the loads to the floor. Bolts are hidden bolts that are used with a spacer sleeve. If speak about cantilever construction, then it is necessary to connect each pair of treads using one such bolt, placing it at the suspended edge. Since all the main loads fall on the wall mount, it becomes possible to use small bolts. This reinforcement option will allow for smaller brackets. So, for each step, it will be sufficient to use one pair of rods, which will have the following parameters: length - 40-60 cm, diameter - 3-4 cm, embedding into the wall - 8-16 cm.

The bolts can be hidden by disguising them as parts of the enclosing structure, and also hidden in the inner part of the riser.

• Fastening to the ceiling with straps. For this work, you will need cables, the material for which is stainless steel 8-10 mm thick. And you will also need to install screw hooks - lanyard. They will help eliminate slack in the strands. This option hanging mount will allow you to make the structure airy, in contrast to the bolt one.

Possible mistakes

When installing a cantilever ladder, there is a chance to miss some of the features of its device, which will lead to the danger of use. The most common mistakes are:

• Incorrectly chosen method of attachment to the building envelope. For example, it would be a mistake to try to anchor to masonry with anchors if the wall is made of slotted bricks or lightweight blocks.
• Unreliability of fastening the brackets to the wall. With the wrong choice of the diameter of the steel anchor or in the case of using a plastic dowel, loosening of the treads may form instead.
• Use of insufficiently thick metal as a bracket or frame. Choice of element diameter less than 3 mm. can lead to twisting of the load-bearing elements.
• Installation of treads on brackets in the wall without using a special damping pad. Its use will allow avoiding the transmission of the sound of a step through the enclosing structure to adjacent rooms.
• Use a material that is heavy enough for the handrail. It is worth abandoning a cast or forged fence, because it will put additional stress on the steps.

1. Introduction

2. Ladders made of natural and artificial stone

3. Concrete and reinforced concrete stairs

4. Wooden stairs

5. Stairs made of steel structures

6. References

7. Introduction

Faulty condition of stairs (corrosion of metal stringers, increased deflections of platforms and marches, loose adhesion of platforms and marches to walls, cracks, potholes, floor delamination in staircases and steps, indentations in steps from abrasion, loosening of the fastening of fences, handrails and safety nets, damage railings, decay of wood, insufficient strength of the fastening of the bowstrings to the strut beams, etc.) should be eliminated as they appear and no further destruction should be allowed.

Metal elements of stairs should be painted periodically every five to six years, pre-cleaning the surfaces from rust. Metal stringers must be plastered or painted

providing a fire resistance limit of 1 hour.

In case of deflections of flights of stairs and landings exceeding the permissible limits (in the case of increasing deformation), employees of the housing maintenance organization must strengthen the load-bearing elements of the stairs (according to the project), having previously taken measures to ensure the safety of the operation of the stairs.

Sealing of cracks, depressions, potholes and gouges in the structures of stairs should be done as defects appear using materials similar to the material of the structures. Stair steps that have lost their strength in collapsible flights must be replaced with new ones.

The gaps between the flight of stairs and the wall should be sealed with cement mortar. It is recommended to correct chips in the tread rolls by applying pre-made inserts or concreting on site.

In stone steps damaged places should be cut and sealed with stone inserts.

Replacement of damaged and fixing of exfoliated ceramic tiles on staircases with new ones should be carried out immediately after detection of defects.

4.8.6. Cracked and bent wooden handrails should be replaced with new ones. Minor damages (burrs, uneven surface) should be removed by cleaning the surface or replacing individual unusable parts with inserts, followed by finishing the handrail.

Damaged sections of the PVC handrail should be cut out and replaced with new ones of the same shape and color. Handrail insert joints should be welded and cleaned.

Bowstrings that have fallen into disrepair, staircase coverings, steps and damaged parts of fences must be replaced, and loose fences must be strengthened.

When conducting overhaul stairs to provide for the device of ramps.

Staircase structures should be painted every five years.

Ladder elements:

the minimum allowable value of support on concrete and metal surfaces- 50 mm, for brickwork - 120 mm;

permissible violation of the horizontality of landings no more than 10 mm, and stair steps - no more than 4 mm;

the deviation of the railing from the vertical is no more than 6 mm.

Stairwells:

glazing must be serviceable; the presence of fittings on windows and doors (handles, hardware), staircase lighting;

the room must be regularly ventilated, the air temperature is not less than + 16 ° С;

regular cleaning should be provided: sweeping of windows, window sills, heating appliances - at least once every 5 days; walls - at least 2 times a month; washing - at least once a month;

entrances from staircases to the attic or roof (with attic roofs) must be locked.

It is forbidden to use staircases (even for a short time) for storing materials, equipment and inventory, arrange storage rooms and other utility rooms under stair flights.

Gate valves, switchboards and other disconnecting devices located on the stairs must be in closed cabinets, the keys of which are kept by the dispatcher of the housing maintenance organization.

1. STAIRS FROM NATURAL AND ARTIFICIAL STONE

1.1 The divergence of the steps of the outer stairs from freezing

Cause: Incorrect styling

Freezing of the exterior stairs of old buildings can
be the result of an incorrectly executed foundation. When the foundation subsides, the slope of the steps changes, rainwater and snow fall between them, and freezing occurs in winter. The reason may be incorrect installation of the steps. In the right way, when the treads slope outward, is the creation of such profiles when the seams are located above the planes of the treads.

Repair method: in most cases, complete dismantling, then thorough correction of defects and installation of steps by qualified specialists. Naturally, damaged steps are repaired, and some of them are replaced. In the latter case, a more resistant stone material should be selected (granite, syenite, gabbro, andesite, freshwater solid limestone, marble).

1.2 Cracking of steps, violation of the rigidity of the cantilever (hanging) staircase

Cause: Uneven shrinkage of the load-bearing wall; poor termination; poor quality wedging

Defects of flights of stairs with a stringer, in many cases, their destruction is caused by defects in supporting (bearing) structures. Such structures must be inspected on site, to determine from what and how they were made, in what condition
are found, sometimes it is possible to determine at what stage of manufacturing the defect occurred.

In buildings built at the turn of the century, stringers made of wood were used. These beams were usually reed upholstered and plastered. Thus, the structure turned out to be hidden and it was impossible to determine its diseases (fungus, insect damage). In such a situation, it is necessary to replace the supporting structure; repair and re-installation of steps.

1.3 Violation of the continuity of the flight of stairs, fractures of treads, steps, attrition

Cause: Normal wear and tear, mechanical stress

The normal wear and tear of the running line of old steps becomes, over time, the cause of accidents. Typical defects: breakage of the edges of the steps, thinned due to abrasion, the formation of a wavy surface of the steps. Defects are exacerbated by impacts from heavy objects, such as when carrying bulky items.

Repair method: Minor damages of monolithic or wedge-shaped steps are repaired by cutting out a dovetail groove, then dust is removed, moistened and an insert is made of step material or of artificial stone matching in color and structure.

Usually, in the manufacture of artificial stone, stone chips are used, obtained by chiselling a recess for an insert. If it is not enough, then add stone crushed stone. The repair material is prepared for 2/3 of crushed stone of various sizes and 1/3 of cement. Good sealing is essential. In most cases, a solid formwork is required to achieve a reliable result. Re-fabricated or repaired surfaces require a damp treatment for 7 days. The surface of the artificial stone is polished after 1-2 days. Sanding to a mirror finish is impractical as slippery surfaces can cause accidents. The initial signs of abrasion of the treads, which later appear in the form of the formation of waviness or slippery particles, are eliminated by a notch of the surface.

Natural and artificial stone stair defects can be repaired with a variety of modern adhesives. In this case, metal brackets made of reinforcing steel are used in stretched belts (Fig.).

Fig. 1.2. Wedging the hanging ladder

1 - wedging; 2 - hanging ladder; 3 - load-bearing wall

Fig. 1.3. The device of stringers from steel beams

1 - tile flooring; 2 - solution

1.4 Cracks in individual steps, sometimes kinks

Cause: Mechanical stress

When replacing steps or an entire flight of stairs, hanging stairs should be fastened with supports, starting from the base of the wall, from the lower floor and along the outer contour. Work begins with gouging the embedment points. The steps are dismantled from top to bottom. New marches are mounted from below, paying attention to the correct installation of the tread planes so that water flows freely from them when washing the stairs. When replacing individual steps, they enter, at least, to a depth of half a brick with wedging and embedding with bricks on cement mortar (Fig. 1.2). If replacement is not necessary, then the flights of stairs can be reinforced with stringers made of steel beams (Fig. 1.3).

1.5 Shell-like delamination of ladder material, cracking

Cause: Exposure to fire

Natural stone is not resistant to fire, although it itself does not burn. Under the influence of high temperature, it cracks, exfoliates, crumbles. Limestones lose their strength to a large extent under the influence of a relatively low temperature; chemical processes(lime burning). Igneous rocks behave better in this respect. If water unexpectedly gets on hot stone steps when extinguishing a fire, then it can severely damage the material from which they are made, and lead to severe destruction of stone structures.

1.6 Loose Railing

Cause: Loose handrail posts, kinks due to corrosion

A characteristic defect of stair railings is loosening of the racks at the attachment points, cracking of the stone. The reason may be severe corrosion of metal racks, freezing at their base, mechanical stress (forced loosening), exposure to water, grinding effect from movements in the seams of particles with sharp edges.

It is necessary to periodically inspect the railing posts. At the initial stage of the development of a defect, you can use a simple pouring of cement mortar, followed by grouting with a sand-cement mixture (1: 1), which sometimes stops further destruction for many years.

When repairing more significant defects, it may be necessary to install a new socket or replace a rusted rack. Attention should be paid to the care of concrete during its hardening period, since the rapid drying of a small amount of concrete or artificial stone leads to its destruction. A good result can only be achieved with proper care and normal moisture.

2.1. Fractures, cracks in concrete stairs

Cause: Cracks in a stretched or compressed belt

Cracks appearing in the compressed chord of stairs reinforced as double-support beams indicate a weakening of the cross-section and can cause trouble. If the edges of the cracks in concrete are colored, peel off, this indicates a defect in the compressed belt. After an expert assessment, it is necessary to take measures to strengthen or replace the structure.

2.2. Weakening the sealing of cantilever (hanging) stairs

Cause: Insufficient size of the embedment length, due to which loosening occurs; improper installation of steps, due to which water flows down to the wall when washing the stairs.

The repair method is identical to that described in clause 1.4.

2.3. Damage to linings, potholes, fractures

Cause: Mechanical effects: natural abrasion, waviness, damage by loads carried along stairs

The repair method is identical to that described in clause 1.3.

2.4. Abrasion of plastic or rubber mats covering treads, tears

Cause: Mechanical stress

The destroyed plastic or rubber inserts on the treads are removed, the concrete surface is cleaned, and after checking the correctness of the slope, new ones are glued.

2.5. Fractures, curvature of handrails, deformations of stringers, fractures of monolithic staircases

Cause: Construction defects, mistakes in the care of concrete, corrosion of reinforced concrete, damage to concrete under the influence of acids, alkalis, oils, fats

In any case, expert judgment is needed. After the necessary examination and calculation, a decision is made to repair or replace, in the latter case, factory-made elements can be used.

2.6. Weakening of concrete of external stairs, chipping, fractures, surface flaking

Cause: Exposure to frost during hardening or frequent freezing of ready-mixed concrete

Constantly wet or frequently moisturized concrete stairs frost can cause great harm. Especially for outdoor stairs, frost-resistant concrete is used with the use of frost-resistant inert ones and with an appropriate selection of the quality and quantity of cement. The repair of old concrete stairs is only a temporary measure, since further freezing leads to their destruction.

2.6. Deformations of reinforced concrete structures, exposing reinforcement under detached concrete, etc.

Cause: Exposure to fire

Under the action of fire (already at a temperature of 500 ° C), additives to concrete burn out; crushed limestone added to concrete begins to decompose (burnt lime is formed); the strength of the reinforcement also decreases. After any fire, it is imperative to conduct an expert survey and determine further measures on its basis.

3. WOODEN LADDERS

The material for making stairs inside buildings can be soft and hard wood. Frequently used structures are a spiral staircase, a straight or curved staircase without a frame, which are usually well calculated and structurally simple. Their defects are usually the result of damage. In rare cases, damage by insects and fungus occurs. Defects also rarely occur due to corrosion of metal connecting elements.

The way to repair badly worn or broken steps is to replace them completely. Less damage is repaired by inserts. Taking into account the opinion of experts, defects that may arise due to the influence of fungal diseases and insects must be prevented. An essential requirement is the exclusion in all cases of the possibility of wetting staircase structures.

Structural defects of stringers, defects in joints with walls, are eliminated in accordance with the rules for the manufacture of carpentry structures.

A wooden staircase burns out quickly in a fire, so it cannot be designed to evacuate people both inside and outside the building.

In the process of reconstruction of residential buildings, regardless of the bearing capacity and condition of the material wooden stairs should be replaced with reinforced concrete, stairs made of natural and artificial stone, with the exception of internal stairs in one-story houses, if they meet the requirements for material and load-bearing capacity.

4. STEEL STRUCTURE STAIRS

4.1 Bending of load-bearing elements, cracks, fracture of connecting elements, deformation of steps

Cause: Static and dynamic overvoltage

Replacement or reinforcement of load-bearing elements in accordance with the expected additional static or dynamic loads, replacement of a metal step (plate), sometimes stiffening ribs against possible bending.

4.2 Excessively smooth surface not safe to walk on; projections of connecting elements above the step

Cause: Constructive effect

Replacement of steps made initially from slabs without roughness or ribbing. Elimination, in order to avoid accidents, of the protrusions of the connecting elements by lowering them under the plane of the step plate (by welding from the bottom side) or in another way.

4.3 Abrasion of the surface of the steps, polish; serrated edges

Cause: Mechanical stress

Roughing or replacing.

4.4 Deformation of all or part of the staircase from high temperature

Cause: Fire

Depending on the expert opinion, replacement of individual elements or the entire staircase structure, depending on the degree of damage.

4.5 Corrosion of all or part steel structures

Cause: Corrosion

First of all, elimination of the causes of moisture, then cleaning of rust-free structural elements suitable for use, and anti-corrosion treatment.

Steel ladders are very rarely used in residential buildings; in public buildings, offices - in the form spiral staircases(due to limited space). Most of them are used in industrial buildings to approach the appropriate technological posts. Usually, for flights of such stairs, high steps (more than 20 cm) are characteristic; steep staircases are equipped with double-sided railings. Increased attention to the condition of such stairs is very important from the point of view of preventing accidents.

Bibliography:

1. Rules and norms for the technical operation of the housing stock

2. A.V. Kolomeets, E.M. Arievich "Operation of residential buildings", reference manual, M. Stroyizdat. 1985

3. NV Nechaev "Overhaul of residential buildings" M. Stroyizdat 1990

4. Boyko M. D. "Maintenance and repair of buildings and structures." Tutorial for universities. L .: Stroyizdat, Leningrad. department, 1986.-256 p.