Quality control, plastering defects. Improved wall plastering: we follow the requirements of SNiP

Often, a project, estimate, terms of reference and other documentation related to repairs in a house or apartment contain such a thing as “high-quality wall plastering”. As a rule, documents do not have a decoding of the term meaning a certain set of operations.

Often this leads to a misunderstanding of the essence of the work and, as a result, to further conflicts between the customer and the work producer. Only an accurate idea of ​​the degree of quality of future work will allow you to avoid problems when repairing your home. This article will help you with this.

Finishing classes

Russian SNiP No. 3.04.01/87 "Finishing and insulating coatings" defines three types of plaster finishes according to their quality:

• simple;
• improved;
• high quality.

Note! The norms and requirements for the quality of plastering work, voiced in the document, are applicable both for self made, and mechanized. Each of the classes of plaster implies compliance with certain rules.

They regulate the permissible maximum deviations from the design values ​​or conditions that are accepted between the parties in the relationship, by default.

Plaster layers

Before we move on to describing the types of plaster in terms of quality, we will talk a little about the finishing layers. This is important for understanding the essence of the topic.

First, the base is sprayed.

1. Its purpose is to ensure reliable adhesion to the surface of the walls of the following layers.. For spraying, a solution having a liquid consistency is used. This makes it possible to hammer in the unevenness of the base, provide a strong grip, and hold all layers of plaster. Layer thickness 0.3/0.5 cm.
2. At the second stage of work, soil is applied. It is necessary for the basic alignment of the plane of the walls. When priming, a solution is used that has a pasty consistency. Its thickness can be 1/2 centimeter.
3. Third layer - lining. It is needed to smooth out small defects and smooth the coating. For it, a solution of a creamy consistency is used. The layer thickness should be 0.2/0.5 cm.

Note! When plastering any type, if the totality of all its layers exceeds 2 centimeters, the base surface must first be reinforced. This can be done using a metal or polymer mesh.

Types of plaster by quality

1. A simple type of finish is used in basements, utility rooms, warehouses, attics. In other words, in all non-residential rooms where an absolutely flat wall surface is not required.
2. Improved plaster is needed in rooms that are directly used by humans. It can be residential houses and apartments, medical, public, educational institutions etc.

1. A high quality plaster class used for works in public, residential, medical, educational, office buildings, with increased requirements for coating. In other words, when the design documentation directly indicates a similar nature of the rough cladding.

SNiP defines the following features of plaster coating classes.

1. A simple type of finish should consist of two mortar layers - spray and soil. Their total thickness should be 2 centimeters.
2. The advanced coating is applied in three coats and consists of spray, primer and top coat. The total thickness of the finish should be about 5 centimeters.
3. A high-quality class of plaster consists of four layers - a spray, two primers and a coating. The total thickness of such a finish should approach 2 centimeters.

Note! The instruction says that the application of improved and high-quality plaster must be carried out without fail along the guide beacons. They are installed on the walls before the main work and can be made from mortar or be finished metal profiles.

A high-quality class of plaster is intended for leveling and smoothing the bases, with their further finishing:

• various paints and varnishes;
• wallpapering;
• facing with ceramic, porcelain stoneware, clinker, plastic tiles.

Quality control of plastering works of this type, carried out according to the minimum allowable SNiP deviations, makes it possible to carry out finishing facing works at the highest level.

It should be remembered that the optimal order for performing the described operations is as follows.

1. The ceiling is plastered first. Next, the walls are processed, in the direction from top / down. Floors must be leveled last.
2. Plaster mortar can be applied to the surface of the base in two ways: spreading it or throwing it.

Related articles:

Finish quality requirements

Deviations that are permissible in terms of the quality of plastering work are given in tables No. 9 and 10, SNiP No. 3.04.01/87.

Permissible deviations in the implementation of work

1. The differences in the plane of the walls from the vertical by 1 meter of their length are 1 millimeter. For the entire height of the room - no more than 5 millimeters. The planes of the walls from the horizontal, for 1 meter of their length - 1 millimeter
2. Do-it-yourself work, please note that the surface of the finish can have no more than two irregularities of smooth outlines per 4 square meters. Their depth or height should not exceed 2 millimeters.
3. Deviations of door and window slopes, arches, pillars, pilasters from the horizontal and vertical should not be more than 1 millimeter.
4. The radii of curved elements and surfaces should not deviate from the design value by more than 5 millimeters. The question arises - how to check the quality of plastering work in this case? This must be done using a pattern template.
5. The width of the slopes from the design value should not deviate by more than 2 millimeters.
6. The deviations of the rods from the straight axis, between the angles of their intersection and the rake, cannot be more than 2 millimeters.

Coating and substrate characteristics

The humidity level of stone, concrete and brick walls during their plastering should not exceed 8%. The strength of adhesion (adhesion) of plaster mixtures (in MPa), for interior work, must be at least 0.1. For external plaster work given value cannot be less than 0.4.

Below is the allowable thickness of each of the finishing layers when laying multi-layer coatings (without the use of polymer modifiers).

1. The thickness of the spray on concrete, stone and brick foundations is not more than 5 millimeters.
2. The amount of spray on wooden surfaces (together with the thickness of the shingles) is no more than 9 millimeters.
3. The soil, consisting of a cement-sand mixture, should have a thickness of no more than 1/2 centimeters.
4. The primer layer, laid from lime, gypsum or lime-gypsum mortar, should not exceed 0.7/1 centimeter in thickness.
5. The covering of the rough plaster finish should be 0.2 / 0.5 millimeters.
6. The covering layer of the decorative coating should not exceed 7 cm.

Note! Important information on how to check the quality of wall plaster. After completion of work, the surfaces should be inspected. They should not have peeling of the coating, cracks, deep scratches, efflorescence, shells, obvious traces of troweling tools.

Requirements for the quality of materials

These provisions are announced in GOST No. 28013/98. "Construction solutions", in the section "General tech. terms".

Also, the requirements for materials for high-quality plastering are given in Table No. 8 of SNiPa No. 3.04.01/87.

Prepared independently or purchased at a concrete plant, a ready-made plaster mixture must comply with the following characteristics.

1. The solution intended for spraying and priming must pass through a sieve with a mesh section of 3 millimeters. The mixture for covering or single-layer plaster must pass through the cells, measuring 1.5 millimeters.
2. The solution should have mobility in the corridor from 5 to 12 centimeters.
3. Its level of delamination should not exceed 15%.
4. Value water holding capacity mixture must be at least 90%.
5. The strength of the coating must correspond to the value included in the project.

The plaster mixture must be kneaded on sand with a fractionation modulus of 1/2. Solutions for spraying and soil should not contain grains with a particle size of more than 2.5 millimeters.

Sand for covering should have a fractionation of no more than 1.25 mm.

The plaster mixture purchased at the factory must be accompanied by a document on its quality.

It states the following:

• number of the year and time (in hours and minutes) of preparation of the solution;
• brand of the mixture;
• type of binder;
• scope of supply;
• solution mobility;
• the state standard is given;
• the price of a cubic meter of solution and its specific delivery are indicated.

Carrying out work in accordance with the regulatory document

Requirements for the implementation of high-quality plastering work are announced in paragraphs No. 3.1 / 3.17 of SNiPa No. 3.04.01 / 87.

Surface preparation

Prior to plastering, such operations must be carried out.

1. Finished premises must be protected from atmospheric influences and precipitation.
2. Equipped with hydro, heat and sound insulation of surfaces, as well as leveling floor screed.
3. Joints and seams between panels and blocks are sealed.
4. The junctions of door and window blocks, as well as balcony blocks, were sealed and carefully insulated.
5. Windows installed.
6. Embedded elements installed.
7. Test runs of the heating and water supply systems were carried out.

Main works

1. Plastering should be carried out at a temperature of air and processed bases not lower than +10°. Humidity should be no more than 60%. This temperature must be maintained in the premises constantly no less than two days before the start and twelve days after the completion of work.
2. Plastering should be carried out on the basis of the PPR - a project for the production of work for the construction of a building or structure.

Note! It is strictly forbidden to apply a plaster finish on surfaces that have areas with efflorescence, rust, bitumen and grease stains. It is necessary to dedust the base before laying each layer of plaster.

1. The strength of the treated surfaces should not be less than the same amount of finish.
2. Protruding bases architectural elements, areas of interfaces of wooden surfaces with stone, brick and concrete structures, should be plastered on a reinforcing mesh fixed on them. Completely wooden bases must be finished on shingle shields.
3. Brick, concrete and stone walls built using the freezing method must be plastered only after they have been thawed from the inside, no less than half their thickness.
4. When working on brick walls, if the air temperature is + 24 ° or more, their surface should be moistened before plastering.
5. When covering the surface with a single-layer plaster, it must be smoothed immediately after application. When using trowels - after setting the mixture.
6. When laying a multi-layer coating, apply each of the layers only after the previous one has cured. The soil must be leveled before it sets.

Conclusion

High-quality plaster according to SNiP ensures that there will be no problems during the subsequent installation of the finish and its operation. Having studied the regulatory documents, you will be able to carry out the finishing on your own or effectively control the work of hired plasterers. When watching the video in this article, you will get even more useful knowledge.

Topic No. 42: “Quality control of plastering works. plaster defects. Causes and their elimination "

Introduction

Currently, there are many methods for engineering survey buildings for various purposes issued by various organizations. Despite such a variety, they all have one thing in common - they, as a rule, consider only questions of field surveys. building structures buildings. This is due to the fact that in the period of the 70-90s of the last century, the customers of such works were various manufacturing enterprises and the task of field surveys was mainly to determine the condition of the load-bearing and enclosing structures of buildings. The results of such work were used, as a rule, by operational services to eliminate the emergency state of building structures.

AT last years the volume of reconstruction and technical re-equipment of enterprises, buildings and structures has grown significantly. At the same time, one of the main tasks is to save material and energy resources. One of the features of modern field surveys is closer cooperation with technologists, designers and specialists in building engineering equipment, and investors and design organizations have become the main customers and consumers of the results of the work. In this case, the necessary amount of information can be obtained only through comprehensive surveys covering a wider range of issues.

In some cases, the reconstruction of buildings is associated with their conversion. At the same time, new technological equipment, which has its own characteristics, is located in the existing volume of the building. In this case, in addition to the work to determine the bearing capacity of the frame for new loads, it is necessary to determine the actual fire safety of the building. Carrying out such work is also necessary due to significant changes in the regulatory framework, which requires the identification of compliance with the space-planning and design solutions of the building, as well as fire extinguishing systems, with these new standards.

Reconstruction of a building with its superstructure or other changes in space-planning decisions also requires obtaining information about the existing systems of engineering equipment. This is an assessment of the state of communications, surveys of thermal and energy inputs to the building, identification of the compliance of existing thermal power capacities with the proposed changes in the building.

The emergence of another new type of survey work is associated with the problem of economical use of heat and energy resources. When reconstructing an existing building, this problem is solved mainly in two ways.

The first- an increase in the thermal properties of building envelopes that meet new, higher regulatory requirements.

Second- improvement of building engineering equipment systems.

Choice optimal solution reconstruction of a building with the lowest energy consumption during its operation is achieved by an energy audit - conducting thermal surveys of enclosing structures and engineering systems and a technical and economic comparison of their effectiveness.

Comprehensive surveys of reconstructed buildings should include the following sections:

Survey of the operating environment;

Inspection of the condition of load-bearing and enclosing structures;

Inspection of engineering equipment systems and energy audit;

Estimate fire safety reconstructed building.

Based on such a wide range of issues to be resolved during a comprehensive survey of reconstructed buildings, the composition of survey participants also changes significantly. In this case, the survey team should also become complex, i.e. it should include specialists in the study of the microclimate of premises, engineers in assessing the condition of load-bearing and enclosing structures, specialists in inspecting engineering equipment systems and in fire safety of buildings.

1. Plaster. Appointment. Variety of plaster. Quality control of plaster works

Plaster is a finishing layer on the surface of various structural elements of buildings, walls, partitions, ceilings, columns, etc., which levels these surfaces or gives them a certain shape or texture. Various types of plasters are used for surface finishing, depending on the purpose, the material from which they are made. structural elements, and the conditions in which they will be during operation.

Application of plaster.

Plaster has a sanitary, protective, constructive and decorative purpose. Sanitary and technical purpose plastering is to obtain even and smooth surfaces of building structures, prepared for painting and cladding, to eliminate the possibility of dust settling on them and to facilitate cleaning from pollution.

Surfaces of prefabricated concrete elements with a clean smooth surface are not subject to plastering. Protective and constructive purpose plastering of enclosing and load-bearing structures of buildings is to protect structures from the harmful effects of dampness, increase resistance to heat transfer, reduce sound conductivity, and protect against the effects of chemicals. The plaster must meet the climatic conditions of the construction area, fire safety requirements, temperature and humidity conditions of the room, technological requirements production, as well as to protect building structures from the action of aggressive environments. In accordance with this, a number of special-purpose plasters are used - waterproofing, acoustic, etc. decorative plastering consists in creating a special texture on the surface of the plaster layer by selecting the composition of the solution according to the material (aggregate and binder) and color, the method of its application and subsequent processing of the finishing layer with various tools and devices.

The most commonly used plasters of the following types:

- colored- on lime-sand mortars with the addition of pigments for their coloring; their surface is treated in a semi-plastic state for a rough and embossed texture of stones;

- stone- decorative plasters on cement mortars with stone chips;

- terrazitic- with a surface treated in a semi-dry state for a smooth or slightly embossed structure;

Sgraffito is a two-, three- or multicolor ornamental pattern on a plastered surface, obtained by scratching and scraping off thin colored layers of plaster.

Varieties of plaster depending on the type of plastered surface.

Finishing with plaster of various kinds of surfaces requires various materials and methods of preliminary preparation of these surfaces. Wet plaster on stone is usually done with a lime or complex mortar when finishing internal brick surfaces and cement mortar on concrete surfaces with a preliminary notch in case of insufficient surface roughness. In both cases, the solutions include various fillers and additives, depending on the purpose and operating conditions of the plastered surfaces. Dry plaster on stone is attached by gluing back side sheets with special mastics, which are applied to the base in the form of separate adhesive marks and beacons, as well as nails to a pre-arranged wooden frame or on screws to special aluminum structures. Wet plaster on wood is made from a lime-gypsum mortar with additives. Sheets of dry plaster are fixed to wooden surfaces with screws or thin nails with wide caps recessed into the sheet. Plaster on a metal mesh or reinforced plaster is used when it is necessary to create a plaster layer on the slope of the finished structure and is made on the basis of a rigid metal frame along partitions, walls, metal beams, etc. Such a frame is also performed when sealing furrows for hidden laying of pipelines, when creating thickened outlines over 20 mm, when finishing with plaster protruding concrete, brick and wooden architectural details (cornices, rods, belts, etc.), when plastering joints of surfaces of structures made of dissimilar materials (wooden with brick, concrete, etc.), joints of door frames with walls and partitions. The metal mesh reinforces the plaster, which prevents the appearance of cracks on it along the line of such joints.

Varieties of plaster according to the method of execution.

All types of plaster can be divided into two groups that are fundamentally different from each other in the production of work. The first, main and most common, group includes wet, or monolithic plaster, the second - dry plaster. Wet plaster is created by applying a plaster solution to the surface to be treated, dry- facing of the treated surfaces with separate sheets made at special factories.

The disadvantages of wet plaster are the duration and complexity of implementation, the duration of the hardening and drying of the mortar, and a large amount of moisture in the room. All this inevitably extends the period of putting the object into operation.

The advantage of wet plaster is a monolithic connection with the surface being plastered, in which the gaps in the structure are closed and no gaps are formed between the structure and the plaster; with monolithic plaster, seamlessness is ensured, the possibility of giving the surface any shape, as well as its use in wet rooms.

Wet plaster is universal and in some cases irreplaceable; it is used for finishing both internal and external surfaces. Dry plaster is more individual in relation to the production of works: its implementation is not associated with the loss of time for hardening and drying; work can be done by less skilled workers; subsequent finishing can be started immediately after upholstering the surfaces with sheets of dry plaster and sealing the seams between them. However, dry plaster is suitable only for finishing the internal surfaces of a building in dry rooms and is inferior to wet plaster in terms of performance, solidity and reliability.

Varieties of plaster according to the degree of quality assessment.

Plain plaster are performed in basements and attics of residential and public buildings, in non-permanent buildings, in temporary buildings, in warehouses and non-residential premises where careful surface treatment is not required. Simple plaster is performed under the "falcon", i.e. a layer of ground basting (except for spraying) is leveled with the edge of a falcon. The bait is usually applied in two layers - spray and primer, without hanging and checking the rule, the cover layer is not applied, but the surface of the soil is overwritten. The corners of window and door slopes, pilasters, pillars are carefully leveled with a trowel. The average total thickness of the plaster coating does not exceed 12 mm.

Improved plaster usually done in residential and public buildings (schools, hospitals, kindergartens, etc.), as well as in special cases in industrial buildings and utility rooms of high-class buildings, for plastering building facades without special architectural design. Improved plaster is carried out as follows: a layer of spray is applied with a thickness of not more than 9 mm on wooden surfaces and 5 mm on stone, concrete and brick; one or more layers of soil 5 mm thick with cement mortar and

7 mm with lime and lime-gypsum mortars; surfacing layer 2 mm with a surface check by the rule, without sagging of the surfaces. The average thickness of the notch is 15 mm. A covering layer 2 mm thick is rubbed with plastic, wooden or felt floats and smoothed with rubber or steel trowels. High-quality plastering is carried out in buildings and structures, the finishing of which is subject to increased requirements: theaters, museums, exhibition halls, hotels, residential buildings high class, etc. The surfaces of walls, ceilings and slopes must be strictly vertical or horizontal planes.

High quality plaster they are made from a layer of spray, one or more layers of soil and a covering with hanging surfaces and installing beacons, the height of which above the surface to be plastered determines the required thickness of the plaster coating. Lighthouses and brands are made from fast-hardening mortars. The average total thickness of a high-quality plaster coating is 20 mm.

Quality control of plastering works.

Surfaces to be plastered must be thoroughly cleaned of dust, dirt, grease and bituminous stains, and salts that have come out on the surface.

Protruding architectural details, junctions of plastered structures made of different materials should be plastered over a metal mesh or braided wire attached to the surface of the base; wooden surfaces - on shields made of shreds.

When performing plastering work, the following requirements must be met:

Permissible thickness of single-layer plaster:

When using all types of solutions, except for gypsum - up to 20 mm;

From gypsum solutions - up to 15 mm.

Permissible thickness of each layer when installing multi-layer plasters without polymer additives:

Spray on stone, brick, concrete surfaces - up to 5 mm;

Spraying on wooden surfaces (including the thickness of the strips) - up to 9 mm;

Soil from cement mortars - up to 5 mm;

Soil from lime, lime-gypsum mortars - up to 7 mm;

Covering layer of plaster coating - up to 2 mm;

Covering layer decorative finishes- 7 mm.

Deviations of plastered surfaces from the vertical (by 1 m):

With simple plaster - no more than 3 mm (no more than 15 mm for the entire height of the room);

With improved plaster - no more than 2 mm (no more than 10 mm for the entire height of the room);

With high-quality plaster - no more than 1 mm (no more than 5 mm for the entire height of the room).

Horizontal deviations of plastered surfaces (by 1 m):

With simple plaster - no more than 3 mm;

With improved plaster - no more than 2 mm;

With high-quality plaster - no more than 1 mm.

Deviations of window and door slopes, pilasters, pillars, husks, etc. from vertical and horizontal (per 1 m):

With simple plaster - no more than 4 mm (up to 10 mm for the entire element);

With improved plaster - no more than 2 mm (up to 5 mm for the entire element);

With high-quality plaster - no more than 1 mm (up to 3 mm for the entire element).

Deviations of the radius of curved surfaces, checked by the pattern, from the design value (for the entire element):

With simple plaster - no more than 10 mm;

With improved plaster - no more than 7 mm;

With high-quality plaster - no more than 5 mm.

Deviations of the slope width from the design:

With simple plaster - no more than 5 mm;

Deviations of rods from a straight line within the limits between the angles of intersection and rake:

With simple plaster - no more than 6 mm;

With improved plaster - no more than 3 mm;

With high-quality plaster - no more than 2 mm.

Irregularities of surfaces of a smooth outline (by 4 m 2) are allowed:

With simple plaster - no more than 3 irregularities with a depth (height) up to 5 mm;

With improved plaster - no more than 2 irregularities with a depth (height) up to 3 mm;

With high-quality plaster - no more than 2 irregularities with a depth (height) up to 2 mm.

Cracks, bumps, shells, dutik, coarse-haired surface, gaps on the plastered surface are not allowed.

When controlling the quality of wall decoration with dry plaster sheets, the following tolerances must be followed:

- vertically at 1 m height - no more than 2 mm, and for the entire height of the room - up to 5 mm;

- horizontally for 1 m of length - up to 2 mm, and for the entire length of the room - up to 7 mm;

- for husks, mustaches, slopes, pilasters and other details per 1 m of height or length - up to 2 mm, and for the entire element - no more than 3 mm;

- over the width of the lined slope - no more than ± 2 mm; the height and depth of irregularities when checking with a two-meter rail - no more than 2 mm, sagging in the walls - 2 mm;

- the width of the seams to be sealed between sheets of dry plaster is no more than 6 mm.

The glued sheets of dry plaster are suitably prepared and painted or covered with wallpaper.

2. Technical inspection of buildings and structures before overhaul and reconstruction. plaster defects. Causes and their elimination

Reconstruction means the reorganization of something in order to improve its functional, structural, aesthetic and other properties in the process of subsequent operation.

For the implementation of reconstruction work, special technology is needed, since these works are carried out in cramped conditions, sometimes in old buildings that are extremely inconvenient for this, in existing workshops. All this complicates the use of available means of mechanization, complicates the delivery of materials and structures to workplaces, and prevents their normal storage in the work area. This ultimately leads to an increase in the cost of manual labor, and in particularly cramped conditions often causes an increased danger of their implementation.

A distinctive feature is the need for a technical survey.

Survey – a set of measures to determine and evaluate the actual values ​​of the controlled parameters that characterize the operational state, suitability and operability of the surveyed objects and determine the possibility of their further operation or the need for restoration and strengthening.

The need for survey work, their volume, composition and nature depend on the specific tasks set. Reasons for testing may include the following:

It is necessary to survey buildings and structures damaged by accidents, disasters, fires, earthquakes (the purpose of such a survey is to establish the possibility of further operation of the building and develop measures to strengthen structures);

Refurbishment design is required and any refurbishment must be carried out before any refurbishment to provide designers with complete information, even in cases not accompanied by increased loads;

Lack of design and technical and executive documentation;

Changing the functional purpose of buildings and structures;

The need to monitor and assess the state of structures of buildings located near newly built structures;

It requires redevelopment of premises (apartments, offices), before the design of which survey work is also required (during redevelopment, the load, location of partitions, etc. may change);

Increase in operational loads and impacts on structures during redevelopment, modernization and increase in the number of storeys of the building;

Identification of deviations from the design that reduce the bearing capacity and performance structures;

A major overhaul of the facility is planned;

In case of detection of an increase in the deformation of the building (as a rule, this is the opening of cracks in the walls) and it is necessary to find out whether it is dangerous and whether further operation of the building is possible;

It is planned to resume construction in progress in the absence of conservation or after three years after the termination of construction when conservation is performed, for which it is necessary to clarify the current technical condition of the unfinished object (sometimes it is not advisable to continue construction);

Inspection of buildings in order to control their condition in the process of scheduled and extraordinary inspections;

The need to determine the suitability of industrial and public buildings for normal operation, as well as residential buildings for living in them;

You are planning to buy a building or a room in a building, and you need to find out its real condition (a survey is highly recommended, at today's real estate prices a mistake can cost a lot);

When creating as-built documentation for "samostroy" (for as-built documentation, that is, for the project, a description of the current technical condition object), if it is necessary to carry out measurement work to draw up measurement drawings.

Technical inspection cannot be understood as something indivisible. In fact, it includes several stages.

Stages of technical surveys and scope of work. Inspection of building structures of buildings and structures is carried out, as a rule, in three interconnected stages:

Preparation for the survey;

Preliminary (visual) examination;

Detailed (instrumental) examination.

The scope of work and the sequence of actions for the inspection of structures, regardless of the material from which they are made, at each stage include:

Preparatory work:

Familiarization with the object of the survey, its space-planning and constructive solution, materials of engineering and geological surveys (if necessary);

Selection and analysis of design and technical documentation;

Drawing up a work program (if necessary) based on the technical specifications received from the customer. The terms of reference are developed by the customer or the design organization and, possibly, with the participation of the survey performer. The terms of reference are approved by the customer, agreed upon by the contractor and, if necessary, by the design organization - the developer of the draft assignment.

Preliminary (visual) inspection:

Continuous visual inspection of building structures and detection of defects and damages by external signs with necessary measurements and their fixation.

Detailed (instrumental) examination:

Work on measuring the necessary geometric parameters of buildings, structures, their elements and assemblies, including the use of geodetic instruments;

Instrumental determination of parameters of defects and damages;

Determination of the actual strength characteristics of the materials of the main load-bearing structures and their elements;

Measurement of the parameters of the operating environment inherent in the technological process in the building and structure;

Determination of real operational loads and impacts perceived by the surveyed structures, taking into account the influence of deformations of the soil base;

Determination of the actual design scheme of the building and its individual structures;

Determination of design forces in load-bearing structures that perceive operational loads;

Calculation of the bearing capacity of structures based on the results of the survey;

Office processing and analysis of survey results and verification calculations;

Analysis of the causes of defects and damages in structures;

Drawing up a final document (act, conclusion, technical report) with conclusions based on the results of the survey;

Some of the listed works may not be included in the survey program, depending on the specifics of the research object, its state and tasks defined by the terms of reference.

Registration of results. Based on the results of the survey, a report is compiled on the technical condition of the structures of the building or structure, which provides information obtained from the design and executive documentation, and materials characterizing the features of the operation of the structures that necessitated the survey.

The final document based on the results of the survey contains plans, sections, lists of defects and damages or a diagram of defects and damages with photographs of the most characteristic of them; layout of cracks in reinforced concrete structures and data on their opening; the values ​​of all controlled features, the definition of which was provided for by the terms of reference or the survey program; the results of verification calculations, if they were provided for by the survey program; assessment of the state of structures with recommended measures to strengthen structures, eliminate defects and damage, as well as the causes of their occurrence.

This list can be supplemented depending on the state of structures, reasons and objectives of the survey.

The technical report is signed by the persons who conducted the survey, the head of the structural unit, the technical director and the executive director. The technical conclusion, which is an integral part of the technical report, is approved by the technical director.

plaster defects.

Internal plaster

Often plaster is made very "skinny". It does not adhere well to the surface of the wall, dusts if you rub it with your hand. Paint or wallpaper

keep on it (Fig. 1).

Figure 1. Wallpaper tearing the "skinny" plaster off the wall. 1 - wall; 2 - wallpaper; 3 - torn off plaster; 4 - cracks; 5 - plinth; 6 - floor covering; 7 - reinforced concrete floor

The reason for this phenomenon is that it lacks a binder - lime. The binder in the plaster during the hardening process firmly binds the aggregate particles to each other, filling the gaps between them, while at the same time ensuring the adhesion of the plaster to the wall surface. If there is so little binder in the solution that the adhesion and stickiness is lower than that of wallpaper glue or paint, then the plaster will crack and collapse.

When the plaster mortar is very "greasy", i.e. it contains more binder than necessary, the plaster also turns out to be of poor quality - it cracks. Moisture penetrates into the cracks and the plaster sooner or later begins to collapse. Naturally, cracks also damage the paint applied to the surface, and it is almost impossible to repair the plaster. Excessive shrinkage of excess lime occurs (Fig. 2).

Figure 2. Cracking of too "greasy" plaster. 1 - cracked plaster; 2 - primer; 3 - floor covering; 4 - wall; 5 - painted surface; 6 - reinforced concrete floor

Insufficient knowledge in the use of building materials for plastering in individual construction has already led to many mistakes more than once. For internal plaster, lime, gypsum and cement mortars are used. Each of them has its own scope, and it is not recommended to replace one solution with another.

Do not apply to concrete surfaces. gypsum mortar. Cement and gypsum enter into a chemical reaction with each other, the plaster swells and then falls off, the gypsum penetrates the surface of the wall and destroys it. To avoid this, lime mortar 0.4 cm thick is applied to the wall. Gypsum should not come into contact with cement or improved lime mortar. It is absolutely wrong to plaster with lime mortar over gypsum, since when it dries, the first shrinks, and the second expands. At the same time, they separate from each other and outer layer disappears (Fig. 3).

Figure 3. Gypsum plaster cracks when applied to a lime base. 1 - plastered surface; 2 - lime plaster; 3- gypsum plaster; 4 - floor covering; 5 - reinforced concrete floor

Often, internal plaster is damaged during electrical work. Before plastering, tubes for wiring wires or the wires themselves are placed in grooves made in the walls and fixed with plaster. In the same way, wooden inserts for hooks for hanging chandeliers are fixed, since the gypsum mortar quickly sets and gains the necessary strength. This method is used in electrical work, however, it is often used for fastening wiring without considering the above with regard to the reactions that occur

between concrete wall cement and gypsum (Fig. 4).

Figure 4. Fixing electrical wiring with gypsum mortar. a - fixing wiring; b - fastening a hook for a chandelier; 1 - partition; 2 - gypsum mortar; 3- electrical wire; 4 - junction box; 5 - plaster; 6 - floor covering; 7 - hook; 8 - wooden insert / dowel /

During installation heating equipment gypsum is also used to attach heating pipelines to the walls or when passing them through ceilings. The biggest mistake is made when heating pipes are laid in a wall or ceiling without casing bushings. The bricklayer closes up the holes, but the plaster stays here only until the heating starts. Under the influence of temperature, heating pipes change their

dimensions, but the plaster does not withstand such changes and cracks (Fig. 5).

Figure 5. Movements of heating pipes cause cracking. 1 - cracks in the plaster; 2 - heating pipes; 3 - plastered surface; 4 - floor covering

Along with cracks from thermal expansion, when fixing with gypsum mortar, the pipes begin to rust due to the fact that the gypsum absorbs moisture. This leads to the appearance of rust spots through the whitewash, in some cases - to the failure of the pipes. The use of casing pipes or bushings prevents movements leading to the formation of cracks, but, however, the bushings themselves are fixed with plaster. Since the bushings are made of metal, they are also subject to corrosion (Fig. 6).

Figure 6. Fastening heating pipes with gypsum mortar. 1 - casing sleeve; 2 - heating pipe; 3 - clamp; 4 - horizontal casing sleeve; 5 - gypsum mortar; 6 - reinforced concrete floor

The plaster applied to the walls after a while hardens and becomes durable. Accelerated drying or hardening of the plaster often causes cracks, leading to its destruction. It is necessary to wait until the bottom layer of plaster hardens, otherwise after applying the second layer, both of them may fall off the wall. Do not dry plaster, including central heating. This causes it to crack and fall off. To dry the plaster, not only heat is needed, but also fresh air, which contains the necessary for setting carbon dioxide. If it is not enough, then the plaster dries out, but does not harden. If the solution also contains cement, it also cannot harden, since moisture quickly evaporates when dried. Accelerated drying of the plaster is possible only with good air exchange.
When redevelopment, brick is often used that has already been in use, for example, taken after the demolition of a house, after appropriate cleaning. However, if a brick previously used in chimneys(impregnated with soot and tar), this causes various changes in the plaster, appearing on the surface brown spots, damaging the whitewash, and sometimes the wallpaper. The situation can be corrected only by replacing the brick. The surface of the brick wall is moistened before plastering, because the hygroscopic brick absorbs the water necessary for setting from the solution, and the plaster becomes unusable and cracks.
It is not recommended to plaster directly on a dusty surface, as the dust prevents the mortar from adhering to the wall. It is necessary either to remove contamination from the surface, or to spray the cement mortar with a thin layer (Fig. 7).

Figure 7. Falling plaster from a dusty surface. 1 - wall; 2 - application of liquid cement laitance; 3 - wall surface with cement laitance applied to it; 4 - covering the first layer of plaster; 5 - worn surface

To brick wall As a rule, plaster adheres well. The concrete surface is smoother, especially if planed metal or wooden formwork is used, and is less water-intensive than brick. According to technical standards, before plastering, a thin layer of liquid cement milk is sprayed onto the concrete surface, giving the surface the desired roughness. If this is not done, especially on a precast concrete floor, then the plaster

exfoliates, which is unsafe for people (Fig. 8).

Figure 8. Falling plaster from the ceiling. 1 - plastered wall; 2 - unprepared surface; 3 - falling pieces of plaster

When planning houses in floors, metal beams are often used, which are processed before plastering. To do this, a concrete layer 2-3 cm thick is applied to the bottom of the beam on a metal mesh, which holds the plaster well. The internal surfaces of sewer wells are plastered with cement mortar. If such plaster is not provided with normal care, then it will fall off. Cement plaster is kept moist for at least a week (water is sprayed on the surface or covered with wet burlap). Cement plaster cracks even when the surface is smoothed with a metal trowel. In this case, a crust is formed on the surface, consisting of one cement, the degree of shrinkage of which is higher than the inner layers, as a result of which it cracks and falls off. The plaster stays in place where it is constantly moistened. When they make a restructuring in a house or build up an attic, they often plaster wooden surfaces. Plaster, however, does not stick to wood and to do so, one must sheathe the walls with one or

two layers of shingles (Fig. 9).

Figure 9. Plastering a wooden wall on shingles. 1 - rack; 2 - plank surface; 3 - single-layer sheathing with shingles; 4 - double skin; 5 - applying primer plaster; 6 - soil grouting; 7 - grouting plaster

Interior plaster crumbles if it freezes during application or is applied to a frozen wall.

Plaster defects are in the form of dutik, cracks, peels, etc. and occur for various reasons. To obtain high-quality plaster, it is necessary to take measures to eliminate these defects.
Dutiki - the appearance of swollen spots on the surface of the plaster. In the center of each swollen spot there is a white or yellow dot or yellow spot.
The peeling and swelling of the plaster occurs because the plastering was carried out on damp surfaces or because after plastering they were subjected to constant moisture. Most often it happens on lime and lime-gypsum plasters.

Different types of cracks can be classified as follows:

Cracks caused by the condition of the plaster itself. In this case, we are talking about cracks that occur exclusively in the plaster layer as a result of an unfavorable stress-to-load ratio. In this case, the plaster may crack over its entire thickness, or a crack is formed only in its uppermost layer. Such cracks do not have special dynamics and therefore are characterized as "static" (non-developing) cracks.

Cracks caused by the condition of the base under the plaster. Such cracks occur in the base as a result of deformation. In this case, we are also talking about cracks caused by internal stresses. Since the reasons lie in the defects of the base under the plaster layer, such cracks are characterized as "conditionally static" (dynamically developing under the influence of external factors).

Cracks caused by the building structure. Here we are talking about developing cracks resulting from settlement and movements of the structure itself. Such cracks may be due to a change environment. For this reason, such cracks should be classified as "dynamic" (heavily loaded).

Depending on the overall picture, there are different types of cracks:

Microcracks. Microcracks are characterized as randomly located cracks, indistinguishable to the naked eye. Such cracks are formed only in the upper layers of the coating, most often due to shrinkage of the mineral components or when applying paint coatings at high temperatures, they do not go to the entire depth of the coating and do not reach the underlying layers. Since microcracks do not go through the entire depth of the coating, they do not violate the technical and physical characteristics material.

Hair cracks. Hairline cracks are characterized mainly as randomly located, arising from the aging of the material, exposure to atmospheric loads under conditions of temperature extremes, moisture, and thermal deformation during operation. When moisture gets into such cracks and with further freezing/thawing, they progressively open and increase in length. In the absence of measures for timely repair, this type of static cracks can develop into conditionally static ones.

Dead end cracks. Dead-end cracks are characterized predominantly as horizontally extending (with downward bending) cracks. Void formation is possible in the region of the lower edge of the crack.

Dead-end cracks occur in a plastic, not yet hardened layer, namely:

When applying too thick a layer of plaster (in one pass);

In case of poor setting of the plaster coating with the base;

With too long and intensive grouting of the plastered surface;

If the consistency of the plaster is too soft.

Shrinkage cracks type A. Shrinkage cracks are a grid with a distance between "nodes". The reason for the occurrence of such cracks is the wrong composition of the plaster, a violation of the technology of plastering. When using modified plasters, such cracks may appear due to a low concentration of cellulose ethers in their composition or with an increased content of cement.

Shrinkage cracks type B. Shrinkage cracks type B also appear as a grid or look like ramifications and are referred to as "Y" cracks. Such cracks can reach the base. Such cracks can occur if:

Substrate and plaster coating system are incompatible;

On the base there is a layer that prevents the setting of plaster materials;

There is a material incompatibility within the plaster coating system;

The holding period (curing time) is not respected;

Too rapid dehydration of individual layers or the entire coating due to heat, sun exposure, wind or a highly absorbent substrate.

Diagonal cracks in the corners of the openings. This type includes cracks, as a rule, passing diagonally from the corners of the openings of the building. The reason for the occurrence of such cracks lies in the fact that in the corners, due to openings, which are one of the most loaded sections of the building, other sections of the base break.

Cracks in joints and seams. As the name itself says, these cracks are a uniform pattern of cracks located at the joints and filling of panel joints or in the seams of the masonry of the building envelope, and are identical with them in the form of formation.

The most important causes of this type of cracks are as follows:

Deformation of the outer surface of large-format blocks or panels as a result of thermal exposure and moisture, which are not covered with plaster for a long period of time. The reason for this is that the "E" modulus (modulus of elasticity) of the plaster is too high and the strength level is too high;

Very different properties of masonry materials and/or joint filler (mixed masonry);

Changing the thickness of the plaster layer over the gaps of brick or panel masonry with poor filling of support and connecting joints.

Causes and their elimination

There are various reasons for the formation of cracks. Cracks can occur:

Due to the curing of the binder or its accumulation on the surface (formation of the iron layer) during application;

When there is a discrepancy between the level of strength and the area of ​​application or due to a violation of the particle size distribution curve, for example, during mechanical application, when light impurities are ground;

Due to shrinkage and swelling of the base under the plaster layer, for example, with mixed masonry or when using building materials, which swell especially strongly when absorbing a large amount of moisture;

Due to thermal swelling and shrinkage of the base under the plaster, if materials with different thermal conductivity are used (for example, at the border of mixed masonry);

As a result of movements of the ground base (construction soil) or the bearing base of the building (for example, the so-called settlement of the structure); in this case, we are talking about especially serious cracks, which should be paid special attention during repairs;

Due to the specifics of the material itself (for example, in mineral decorative plasters).

Whenever any deformation takes place, internal stresses occur that exceed the internal strength of the plaster coating, and the probability of cracking in the coating is especially high. At the same time, accumulations of binder on the surface, discrepancy between the strength of materials and the field of application, strong swelling of the base under the plaster as a result of thermal exposure or moisture penetration and its shrinkage, as well as improper preparation of the base for plastering are essential.

Cracks, delaminations and voids due to surface swelling and too high internal stresses in very hard plaster at the masonry boundary.

Accurate characterization and classification of cracks in plaster is especially important issue, since the results of this assessment will need to determine the possibility of their repair. Based on the general picture of the defect and the shape of cracks, it is possible to draw a conclusion about the causes of their occurrence in order to correctly classify cracks in the future and propose appropriate measures for their elimination or repair.

Table 1 shows plaster defects and how to eliminate them.

Table 1. Plaster defects, their causes and remedies

	The reasons for their appearance	Prevention measures and remedies
Dutiki on the surface	The presence in the solution of small particles of unextinguished lime	Withstand the lime dough until the lime is completely extinguished. Mix the solution thoroughly. To correct, beat off and clean the damaged places where the dutik appeared, and repair them with a solution flush with the surface of the plaster
Insufficient strength	Weak mortar due to insufficient quantity or poor quality of the binder or high contamination of the sand	The compositions and brands of solutions, depending on the type of surfaces, the purpose of the premises and the humidity of the air during their operation, must comply with the accepted data. The quality of the sand must comply with GOST 8736. Insufficiently strong plaster, identified after tapping, is beaten off with a percussion instrument, cleaned and re-plastered the surface with a quality mortar with appropriate preparation of the base
Cracks on the surface	Application of too greasy or poorly mixed solutions	When preparing solutions, correctly dose binders and aggregates and mix them well
	Fast drying of plaster under the influence of strong through winds and high temperature. Applying thick layers of mortar to freshly applied unset mortar	Eliminate drafts when plastering surfaces and observe normal temperature conditions. The thickness of each soil layer should not exceed 7 mm for lime and lime-gypsum mortars and 5 mm for cement mortars. Apply the solution only on well-set previous layers.
	Absence of a metal mesh or weaving of wire over nails in places where structures made of dissimilar materials are joined	Nail strips of metal mesh at the junctions of the wooden parts of buildings with brick, concrete or gypsum concrete structures. To fix cracks and crevices, it is good to moisten these places with water, grease them with a solution and rub them. In places where structures made of dissimilar materials are joined, beat off the plaster, clear these places, nail strips of metal mesh or braid with wire over nails and re-plaster
Bloating and flails	Plastering on wet surfaces or permanent dampening after plastering, especially when using lime and lime-gypsum mortars	Before plastering damp places must be dried well. To correct, beat off the plaster in places of swelling, clear these places and re-plaster them
Rough surface	Application of a covering layer from a solution prepared on coarse sand	Use for the covering layer a solution prepared on strained lime and sifted sand. Strain the covering solution. To correct, grind the plaster with a solution prepared in fine sand and filtered through a sieve with 2 mm holes
Peeling	Applying the solution to a contaminated or dry surface not wetted with water, or to dried layers of a previously applied solution	Thoroughly clean the surfaces of brick, concrete and other structures from dust, dirt, grease stains, as well as from salts protruding on the surface, and moisten with water. Apply subsequent layers of plaster immediately after setting of the previous layer, if the latter is made of lime-gypsum, lime-cement or cement mortar, and after whitening of the previous layer, made of lime mortar
	Subsequent layers of the solution are applied to less durable previous ones.	Apply the subsequent layers of the solution on the more durable previous ones. To repair, beat off peeling plaster, carefully clean in compliance with the above conditions.
Surface irregularities	The plaster is made by subsoiling without checking the surface by the rule	Check the surface with a rule of 2 m in length. In places of depressions, make an additional spray coating and wipe. Clean off the bumps with a trowel, spray and wipe.
Grainy surface texture and circular stripes	Poorly executed spray grout. The solution is prepared on coarse-grained unscreened sand.	Make an additional spray of toppings from a solution prepared on fine sifted sand and wipe the surface.
Shells on the surface	Preparation of a solution on unextinguished lime	Wet the surface with water several times within two weeks. After the surface dries, spray and wipe off.
Grease and rust stains	Contamination of the mortar, the nail heads of dry plaster are not oiled.	Clean spots with stains to the full depth of the plaster layer and re-plaster; clean the nail heads from rust and proliferate.

3. Expert survey of buildings and structures

The expert survey of buildings consists of the following stages:

Preparatory, general and detailed survey of the object;

Calculations of strength, stability and deformation of load-bearing structures and buildings, structures as a whole;

Drawing up a technical report.

At the preparatory stage, it is necessary to study archival materials, the norms according to which the design was carried out, to collect initial data and illustrative materials.

The initial data for the performance of work is:

Terms of reference with a certificate of expiration of the estimated service life of the building;

Inventory floor plans and technical passport for the building; in the absence of these materials, a specialized organization must perform measurement drawings;

The act of the last general inspection of the building, performed by the maintenance service (the absence of an act is not a reason for non-performance of work);

Information about the construction site (subsidence soils, the presence of a side job, etc.), in the absence of such data, the organization conducting the survey must obtain them independently;

Geo-basement performed by a specialized organization (the absence of these materials increases the amount of work to determine the properties of the base soils).

A general survey is carried out for a preliminary acquaintance with the building and drawing up a program for a detailed survey of structures. During a general examination, the following work must be performed:

Establish a structural diagram of the building and identify the location of load-bearing structures in terms of and in height;

Perform a complete inspection and photography of roof structures, door and window blocks, stairs, load-bearing structures, facades;

Mark the places of workings, openings, probing of structures to obtain reliable (at a level not lower than 0.95) data;

To study the features of nearby areas of the territory, vertical layout, the state of improvement of the territory, the organization of the withdrawal surface water;

Establish the presence of backfilled ravines, landslide zones and other hazardous geological phenomena near the building;

Assess the location of the building in the development of quarters in terms of backwater in the smoke, gas and ventilation ducts.

A detailed survey is carried out to clarify the structural scheme of the building, the dimensions of the elements, the condition of materials and structures in general.

During a detailed examination, work should be carried out to open structures and joints with measurements, sampling, checking and evaluating deformations, testing selected samples, to determine the physical and mechanical characteristics of structures, materials, soils, etc. All types of work must be carried out using tools, instruments, testing equipment.

Calculations of the strength, stability and deformability of individual structures and the building as a whole, taking into account their real state, make it possible to identify the available reserves of bearing capacity and make a forecast of the duration of trouble-free operation.

If the survey revealed the presence of places of freezing and getting wet in the walls of the building, then it becomes necessary to perform heat engineering calculations. The results are taken into account when developing recommendations for carrying out repair activities.

The technical report on the expert examination should contain:

The list of documentary data on the basis of which it is compiled;

The history of the building;

Description of the surrounding area and building site;

Description of the general condition of the building according to external inspection with photographs of facades and damaged structures;

Drawings (including measurements) of plans and sections;

Marking drawings of structures indicating the places of openings;

Defective lists of all structures and places of openings, indicating the amount of physical wear;

Thermal engineering calculations(if necessary);

Calculation of acting loads and verification calculations of the base, foundations and load-bearing structures;

Scheme of the plan of the building and site with the application of pits and wells, sections of pits and wells;

Geological and hydrogeological conditions of the site, construction characteristics of soils, information on seismicity and displacement trough;

Determining the physical deterioration of the building as a whole;

Analysis of the causes of the emergency state of the building, if any;

The foundations of buildings have a physical wear of 60% or more, if the signs of their wear are characterized by the following defects:

Curvature of the horizontal lines of the walls;

Draft of individual sections;

Distortions of window and door openings;

Complete destruction of the basement;

Significant heaving of the soil.

Inspections establish the presence of these defects, while performing the following work:

Study of soils by drilling;

Opening control pits;

Checking the presence and condition of waterproofing;

Laboratory analyzes of soils and water, laboratory studies of foundation material;

Verification calculations of the bearing capacity of foundations and foundations.

In accordance with SNiP 2.02.01-83*, SNiP II-22-81 and SNiP 2.01.07-85*, the loads and impacts transferred to the foundation by building foundations are established taking into account the joint operation of the building and foundation structures.

The number of exploratory wells is determined according to Table 6SN RK 1.04-04-2002.

Control pits for examining the structure, dimensions, material of the foundations are arranged 2 ... 3 per building. Pit holes are torn off from the outside or inside depending on the ease of opening.

The pits are torn off below the base of the foundation by 0.5 m. If bulk, peaty, loose or other weak soils are found at this level, a well should be laid in this place to determine the thickness of the layer of weak soil.

The minimum size of the pits is determined according to Table 7 of SN RK 1.04-04-2002.

The length of the exposed foundation must be at least 1 m.

Inspection of foundations and bases within the opened pit is carried out as follows:

Establish the type of foundation, its shape in plan, dimensions, depth of laying, previously made reinforcements, as well as grillages and artificial foundations;

Examine the masonry with the definition mechanical method grades of stone and mortar;

Take samples of soil and masonry material for laboratory testing;

Install waterproofing.

To determine the physical and mechanical characteristics of soils, it is necessary to select rocks with disturbed and undisturbed structure. At the same time, in laboratory conditions, the density, bulk density and moisture content of the soil are determined. If necessary, hygroscopic moisture, porosity, particle size distribution, plasticity, water resistance, etc. can also be determined.

The physical deterioration of brick, stone and wooden walls is estimated at 61% or more if their condition is characterized by the following features:

Noticeable curvature of the horizontal and vertical lines of the walls;

Massive destruction of masonry, blocks or panels;

The presence of temporary fasteners;

The deviation of the columns from the vertical is more than 3 cm;

Bulging more than 1/50 of the height of the room;

Weathering seams to a depth of more than 40 mm;

Cracks and delamination of the protective layer, corrosion and in some places breaks in the reinforcement of reinforced concrete columns;

Rotted wood walls.

With a detailed examination of walls, columns and load-bearing partitions, the following is performed:

Description of the identified structural defects and their assessment;

Mechanical Definition strength of the material of construction;

Laboratory testing of material strength;

Verification calculation of structural strength from the impact of operational loads;

Thermal calculation.

Verification calculation of the strength of structures is performed in accordance with SNiP II-22-81 for bearing capacity, for the formation and opening of cracks, and deformations.

Material stone walls determined by control probing. For this, bolts with a diameter of 16 ... 20 mm and electric drills are used.

The strength of the wall material at the site of the survey can be determined using Fizdel's, Kashkarov's hammers or the TsNIISK instrument. Tapping the walls, in addition to determining the strength, makes it possible to establish the quality of adhesion of the brick to the mortar, to determine the areas of chipping of the mortar and the mobility of the brick.

The number of samples for laboratory testing of the wall material is set depending on the size of the building (Table 9 of SN RK 1.04-04-2002).

Signs characterizing wear in 60% or more prefabricated reinforced concrete floors, floors from double-shell rolled panels and from precast concrete flooring, wooden floors, the following:

Deflections, in some places falling off of the concrete of the lower slabs;

Detachment and exposure of the ribs of the upper plates;

Multiple deep cracks in the slabs;

Displacement of plates from the plane;

The deflection of double-shell reinforced concrete panels is more than 1/50;

Deflections of reinforced concrete floorings more than 1/80, prefabricated and monolithic solid slabs up to 1/100;

Deflections of monolithic and prefabricated reinforced concrete, metal beams more than 1/150;

Corrosion of reinforcement more than 10% of the section;

Reducing the cross section of beams by more than 10%;

Severe damage to wood by rot;

Deflection of wooden beams and girders.

During instrumental examination, a preliminary examination is carried out to establish the material and design scheme of the floors, visual definition places of deformation.

Determination of the section of reinforcement of reinforced concrete structures, the location and section of metal elements in vaulted ceilings is performed using ISM devices or a ferroscope.

During the examination, the following should be determined:

Locations and dimensions of supporting structures;

Spans of beams and girders, the distance between them.

The strength of the floor material is determined on samples by laboratory analysis, as well as in the process of examination with a Fizdel and Kashkarov hammer, a TsNIISK pistol and an ultrasonic device UKB-1.

Verification calculations of floors are carried out to establish the actual stresses in the material of structures caused by acting loads, taking into account operating conditions and the actual strength of the material. Depending on the material of the floor structures, the calculation is performed in accordance with SNiP 2.03.01-84*, SNiP II-23-81* and SNiP 2.01.07-85*.

In necessary cases, to determine the strength characteristics of the floor elements, proof load tests can be carried out.

The loading scheme in each case is assigned in accordance with the structural scheme of the floor. The structure is loaded with a control load q k. The load from its own weight is calculated from the volumetric weight of the material of the structure, which is determined in the laboratory, while an overload factor of 1.1 is introduced to the calculated weight.

The live load q vr is accepted with a reliability factor equal to 1.2 ... 1.3, based on the current load standards for this type of premises in accordance with SNiP 2.01.07-85 *.

Floor deflections are determined by the P-1 deflection meter, as well as by a level with a special nozzle.

To determine the strength characteristics of the floor material, openings are carried out, the number of which is prescribed depending on the area being examined (Table 16 of SN RK 1.04-04-2002).

Balconies (loggias) in the presence of slab deflections of more than 1/100 of the span, cracks of more than 2 mm, wall buckling of more than 1/150 of their length are classified as emergency structures.

During the instrumental examination of balconies, the following is carried out: preliminary inspection, opening, establishing the nature of deformations, testing structures with a test load, performing verification calculations. Depending on the material of the structures of balconies, the calculation of the strength and deformability of their elements is carried out in accordance with SNiP 2.01.07-85, SNiP 2.03.01-84 *.

In necessary cases, tests of balconies are carried out with a test load similar to tests of floors. At the same time, the structural schemes of balconies and the stresses that depend on them, arising in the supporting structures from the acting loads, are taken into account.

Instrumental examination of roof elements is carried out similarly to the methods of examination of ceilings, if there are cracks of more than 2 mm in construction trusses or balconies, deflections of slabs or beams of more than 1/100, damage to slabs over an area of ​​more than 20%, the roof is assessed as emergency. During the examination, the type and material of the supporting structures are established, a laboratory analysis of the strength characteristics of the material of the supporting structures is carried out, verification calculations of stresses in the roof elements from existing loads are performed.

In the presence of deflections up to 1/150 of the span, local destruction, cracks in the joints of marching plates, deflections of steel stringers with a weakening of their connections with the platforms, destruction of cuttings in structures wooden stairs, rot of wooden elements, the condition of the stairs is classified as emergency. In the process of instrumental inspection of stairs, an external inspection of the supporting structures is carried out, if necessary, an autopsy is performed with sampling of materials for laboratory analysis, and a verification calculation is performed.

The deflection of the supporting structures of the stairs is determined by the P-1 deflection meter, as well as by a level with a special nozzle. The obtained measurements are compared with the maximum allowable deflections established for the emergency state of this structure.

The scope of work on the study of wooden load-bearing structures includes determining the quality of wood by drilling with an electric drill or a hollow borer, which allows you to remove a column of wood to judge the change in color, strength of wood, and also to establish the boundaries of damage.

The method for determining the deformations of the bases and foundations of buildings includes the following work.

Before the start of work, a reconnaissance is carried out on the spot.

The purpose of the reconnaissance: to collect information about the state of structures, the presence and nature of cracks; outline the location and design of lighthouses; identify the causes of deformities.

Based on the results of the reconnaissance, the following should be drawn up:

Brief characteristics households and buildings;

Description of the characteristics and condition of soils;

Description of places for laying geodetic signs, justification for their choice;

Approximate scheme of the planned measuring network;

The presence of cracks and the location of the beacons.

After that, a working program is drawn up to determine the deformations of the bases and foundations of buildings.

The work program consists of a brief explanatory note, to which a calendar work plan is attached.

The explanatory note states:

Goals and objectives of observations;

Engineering-geological conditions of the base;

The number of designed signs and their type for measuring deformations;

Instruments and methods of measurements;

Procedure for processing measurement results;

Drawing up a report on the results of observations.

Monitoring of settlements and deformations of bases and foundations is stopped if, during three measurement cycles, their value fluctuates within the specified measurement accuracy.

Measurements of vertical displacements (settlement, rises, etc.) are divided into three classes, which are characterized by measurement accuracy - the value of the root-mean-square error from two measurement cycles:

for class I + 1 mm;

for class II + 2 mm;

for class III + 3 mm.

For a building built on compressible soils, precipitation and subsidence are measured with accuracy class II.

Placement, design and installation of initial benchmarks is performed as follows:

Before starting work on measuring the sediment, a soil geodetic mark is installed, which is laid below the freezing depth;

The ground benchmark can be metal or reinforced concrete; if there are metal or reinforced concrete structures near the building with a laying depth below the freezing of soils, they can be used as ground benchmarks;

It is possible to use benchmarks embedded in the walls of neighboring buildings;

The number of ground benchmarks - at least three, the number of wall benchmarks - at least four;

When laying wall benchmarks, it is necessary that the buildings do not have visible deformations and were built 5 or more years before the signs were laid.

Placement, design and installation of marks is carried out in accordance with the following requirements:

Stamps are installed approximately at the same level, placing them at the corners of the building, at the junction of the transverse and longitudinal walls;

The locations of the marks are indicated by conventional signs (for example -) on the building plan, made on a scale of 1:100 ... 1:500;

Each stamp is assigned a number.

Settlement measurement by class II geometric leveling should be performed:

The leveling move begins with a benchmark and ends on it or on another benchmark; the number of stations in the hanging passage is not allowed more than 2;

The length of the sighting beam should not exceed 20 cm; the height of the sighting beam must be at least 0.5 m above the ground;

After performing a closed move, its discrepancy is calculated; it must not exceed the allowable residual f n .

The measurement results are processed as follows:

At the end of the field measurements, the excess between marks and benchmarks is calculated and a leveling scheme is drawn up, for which the calculated excesses, received and permissible discrepancies are written out; rounding is done to the following values:

Excess 0.1 mm;

1 mm marks;

Draft 1 mm;

Foundation settlements under each brand are calculated as the difference between the mark of this brand, obtained in the last measurement cycle, and the mark obtained in the first cycle;

On the foundation plan, under the number of each brand, write the value of its settlement in mm;

On the basis of the statement of precipitation, statements of average weekly, average monthly precipitation rates are compiled;

Under natural conditions, hydrostatic leveling is used to determine the sediment.

Cracks are monitored under the following conditions:

A beacon is installed on each crack in the place of the greatest opening;

Observations of cracks are carried out until the termination of their disclosure; at each inspection, mark the position of the end of the crack with a stroke applied with paint or a sharp tool; next to each stroke put down the date of inspection;

The location of the cracks is schematically applied to the general drawings;

For each crack, a graph of its opening is drawn up;

For cracks and lighthouses, in accordance with the inspection schedule, an act is drawn up; the act specifies:

date of inspection;

Surnames and positions of the persons who carried out the inspection;

Drawings with the location of cracks and lighthouses;

Information about the state of cracks and beacons during the inspection and replacement of collapsed beacons with new ones;

Information about the absence or presence of new beacons.

List of main literature

3. SN RK 1.04-04-2002 Inspection and assessment of the technical condition of buildings and structures. - Almaty: "KAZGOR", 2003. - 68 p.

4. MDS 13-20.2004. Integrated methodology for the inspection and energy audit of reconstructed buildings. - M .: Gosarchstroykontrol, 2000.

5. MRR - 2.2.07-98 Methodology for surveying buildings and structures during their reconstruction or redevelopment. - M.: GUP "NIATS", 1998. - 28 p.

12. RDS RK 1.04-07-2002 Rules for assessing the physical deterioration of buildings and structures. - Almaty: "KAZGOR", 2003.

17. RDS RK 1.04-15-2004 Rules for technical supervision of the condition of buildings and structures. - Almaty: "KAZGOR", 2005. - 17 p.

28. GOST 5802-86 Building mortars. Test methods. - M.: Publishing house of standards, 1986.

The thickness of the plaster must meet the following data:

• Simple up to 12 mm.
• Improved to 15 mm.
• High quality up to 20 mm.

Requirements for the quality of various types of plaster.

On smooth brick surfaces, the thickness of the plaster can be up to 10 mm, and on new concrete surfaces up to 2 - 3 mm, i.e. covering with grout. On surfaces made of straw, reeds and fiberboard, the thickness of the plaster should not exceed 20 mm without additional preparation. On wooden surfaces, it is desirable to install a layer of plaster with a thickness of 20 mm or at least 15 mm from the level of the output peel, since thinner layers of the mortar are easily torn from warping of stuffed panes, and the peel itself is “imprinted” on the surface of the plaster.

The plaster must adhere firmly to the surface, not peel off; have a well-worn surface, without external defects. The accuracy of the plaster being performed is checked with a rule (rail) 2 m long. To do this, the rule is applied to the surface of the plastered wall in different directions: vertically, horizontally, diagonally. If the deviations are greater than the norms given in Table. 1, they are eliminated (the solution is cut off or additionally applied).

The verticality and horizontality of a simple plaster is controlled by a rule or a cord, i.e., pulling the cord with an indent on the thickness of the plaster and arranging marks and beacons under this cord. For improved and high-quality plaster, the surfaces are hung, stamps and beacons are arranged.

The quality of the plaster

Plaster quality indicators

Indicators	Permissible deviations in the quality of the plaster.
	Simple.	Improved.	High quality and decorative.
Surface irregularities are detected when applying a rule 2 meters long.	No more than three irregularities with a depth or height of up to 5 mm.	No more than two irregularities with a depth or height of up to 3 mm.	No more than two irregularities with a depth or height of up to 2 mm.
Deviations of the surface from the vertical.	15 mm. to the full height of the room.	2 mm. 1 meter in height, but not more than 10 mm. to the full height of the room.	1 mm. 1 meter in height, but not more than 5 mm. to the full height of the room.
Deviations of the surface from the horizontal.	15 mm. for the whole room.	2 mm. per 1 meter in length, but not more than 10 mm. for the entire length of the room or its part limited by girders, beams.	1 mm. per 1 meter of length, but not more than 7 mm. for the entire length of the room or its part limited by girders, beams.
Deviations of husks, mustache, window and door slopes, pilasters, pillars from the vertical and horizontal.	10 mm for the entire element.	2 mm. per 1 meter of height or length, but not more than 5 mm. for the entire element.	1 mm. per 1 meter of height or length, but not more than 3 mm. for the entire element.
Deviations of the radius of curved surfaces from the design value (checked by a pattern) mm.	10 mm.	7 mm.	5 mm.
Deviations of the width of the plastered slope from the design one, mm.	Not checked.	3 mm.	2 mm.
Deviations of rods from a straight line within the limits between the corners of intersection and raskrepki, mm.	6 mm.	3 mm.	2 mm.

Uch.posoble Plastering. Shepelev.A.M.

Plastering is a very important stage of finishing work, on which comfort and beauty in your home depend most directly. In order for the living room and bedroom to always please the eye, it is necessary to pay special attention to the choice of both plaster and builders who will finish the premises. In this article, we will focus on what requirements building mixtures must meet and how to check the quality of the work performed.

To begin with, a few words about the quality characteristics of the plaster. It also protects the surface from various scratches, bumps, chips and other mechanical damage. To solve the tasks, decorative coatings must have good adhesion (strong adhesion to the surface) and water resistance. Adhesion prevents shedding of the material during operation, and water resistance helps to avoid serious problems in case of flooding of the apartment. Among other things, high-quality is elastic. It is no secret that the constant movement of the soil causes small deformations of the supporting structures. If you decide to save money and buy cheap Decoration Materials don't be surprised if they start to crack after a few years.

Now about the requirements for applying plaster. how to put it on the walls, you need to premise and prepare the surface. The old ones for the walls are removed, as, indeed, old plaster. After that, all surfaces are thoroughly cleaned of dust, stains of various origins and other contaminants.

The solution is applied evenly over the entire wall, the layer should not exceed 20 mm. The check begins with an inspection of the corners. By how carefully the joints are made, you will immediately understand whether it is worth waiting for unpleasant surprises. Next, inspect the main surface of the walls. It should be flat and smooth with clearly visible edges at the corners. Any mounds, cracks and potholes are the basis for claims to the builders.

To check the strength of the joints, apply a few blows to the plaster in randomly selected places. Of course, the quality does not allow any delamination. The sound upon impact should be deaf, which indicates the absence of voids and the uniformity of the application of the finishing layer.

The evenness of the walls should also be checked. To do this, take a rule at least 2 meters long and attach it to the plastered surface. If the finishing was carried out by professionals, then the size of the gap does not exceed 5 mm. The verticality of the walls is checked using a plumb line. The quality criterion is the same - the gap should not be more than 5 mm per 2.5 m of the surface.

How to check the evenness of the wall with a laser level - laserpribor

A line laser projects a laser line onto the wall. In this case, a laser plane appears between the wall and the laser level (horizontal or vertical, depending on the model of the level).

A vertical plane is used to check the evenness of the wall!

There are two methods for assessing the flatness of a wall (checking for depressions and bumps on the wall surface):

1. Checking the evenness on large area walls.

2.Check for evenness in a small area.

The method for checking evenness is based on the projection of the beam at a certain angle to the wall and mathematical calculations.

1. Checking evenness over a large area of ​​the wall.

This technique is useful in assessing the scope of plastering work, but can also be used when checking after plastering and painting works. As a rule, before plastering, the differences along the wall are quite large and are already noticeable - this technique will allow us to quantify the amount of work to level the wall with plaster.

It is necessary to turn on the vertical plane of the laser line leveler (plane builder), install the level at the edge of the wall so that the vertical laser plane runs parallel to the wall. This requires marks on the floor along the wall at the same distance from wall A and B, as shown in the figure:

In this case, the builder builds a plane parallel to the planned surface of the plastered wall (not the plastered surface itself, but the plane parallel to it). If a wall section without a laser beam appears on the opposite wall from the level, then the beam is interrupted in some place by the convex part of the wall - you need to move the laser level away from the wall and make new marks A and B.

To check the differences on the wall surface in one vertical section (from to the ceiling), you need to take a steel or wooden meter with a millimeter scale without moving parts (a tape measure will not work precisely because of the movable hook that almost every tape measure is equipped with).

Choose vertical section 1-2 cm and put the meter perpendicular to the wall - the free end of the meter rests against the wall at an angle of 90 degrees to the wall surface, and the laser beam will appear on the tape measure plane, showing the distance from the base laser plane to the wall (size 1). Then we rearrange the meter lower on the same vertical line and get a new distance (size 2). We take as many measurements as needed.

Now the data for this vertical segment can be compared with the data for the vertical segment of the wall in 40 cm or in a meter.

We compare the obtained dimensions and get an idea of ​​the curvature of the wall relative to our base vertical in centimeters and millimeters.

2. Check for evenness in a small area.

When the wall is plastered and the preparation of the wall for gluing or painting is completed, the irregularities, as a rule, are 1.2.3 mm and it is not always convenient to search for them using the first method with a ruler.

Particularly noticeable are the unevenness on the walls to be painted, painted dark and on which direct sunlight falls at an angle ... The same method is used to assess the evenness of the wall after finishing before painting and wallpapering.

This technique is not difficult to apply. To begin with, at the wall that we will measure, visually mark a square on the floor (or draw with chalk or mark with some objects) - we need it in order to then put the builder at the right angle to the wall. We mark points A (the laser plane is perpendicular to the wall), B (the laser plane is at an angle of 45 degrees to the wall), then we mark points C, D, E by dividing the segment between the wall and the previous marked point in half (we get angles 45/2 = 22, 5; 22.5/2 = 11.25; 11.25/2 = 5.62):

At the same time, when a plane falls on a wall, it will be flat at any angle only when the wall is perfectly flat! With unevenness, the beam will bend, and the smaller the angle (the sharper it is), the greater the curvature!

In places of unevenness, the beam will bend relative to the center of the measured area - if it bends away from the builder (point A1), then in this place we have a hole on the wall, if it bends towards the builder (point A2), then there is a bulge on the wall. Let's clearly demonstrate this in Figure 5:

If a horizontal beam is directed at the wall at an angle (it is necessary to tilt the builder relative to the horizontal plane in this case), then it will show the unevenness on the wall from left to right (horizontal curvature), and not from top to bottom (vertical curvature).

How in millimeters is the dip or bulge X? Everything is very simple! You must use the trigonometric formula from the high school course! The cotangent will help us - the ratio of the leg adjacent to the corner (just the distance A1) to the opposite leg (the desired value - unevenness X).

When the angle of incidence of the beam on the wall changes, the ratio of A1 to the desired value X will change. The sharper (smaller) the angle of incidence on the wall, the greater the value of A1 or A2, the greater the coefficient:

A1 / ctg "angle of incidence of the beam on the wall" = X

Here are the values ​​of the cotangent of the angles that we used in the calculations:

And this is an example of calculating the roughness in millimeters, depending on the angle at which the beam falls on the wall:

Source: www.laserpribor.ru

How to check plaster?

Instruction

.1

Before deciding whether the plaster needs to be replaced or not, it is necessary to check its strength, how well it adheres to the wall. Based on the results obtained, mono will draw the appropriate conclusion: it is necessary to re-plaster the wall, leave it in the state in which it is currently, or a small cosmetic repair in some areas will be enough.

.2

The easiest way to check the plaster is to use a scraper or spatula. It is necessary to take the appropriate tool and run it over the surface, in those places where the cement crumb begins to crumble, it is necessary to carry out cosmetic work. The easiest way to check the plaster is to remove the wallpaper from it, if any. If it begins to collapse along with them, then such a coating is no longer subject to partial correction and requires a complete replacement.

.3

To determine the strength of a plastered surface, you can take a simple hammer and tap its handle on the surface. In places where the coating is not securely held, a dull response will be heard, they need to be marked with something. If there are many such places, it is recommended to completely re-plaster the wall.

.4

You can also dry the surface and see if there are damp places on it. As a rule, they will differ in a characteristic color shade, it will be darker. In this case, it is necessary to re-plaster not only the damp area, but also around it by 50-70 centimeters.

.5

If at first glance the quality of the plaster is unsatisfactory, it is not recommended to save money, but to take and replace the entire coating. Grease stains can appear on the plaster, the cause of which often lies much deeper - in the wall itself. In this case, it is recommended to make a chip on the wall and apply a new solution.

.6

It is recommended to check the presence of cracks in the plaster with a small sharp object. Without pressing hard, they need to run through all sections of the wall, when a crack appears, the object will jump or, on the contrary, fall into it. Then the crack needs to be enlarged on its own and covered with fresh mortar. It is worth noting that all work is carried out on dry plaster, so it must first be dried.

Plastering walls - a question about the quality of work - a discussion on the forum ngs.dom in novosibirsk

You will need a rule-level 2m long and a simple ruler. Standard tool for quality control.

Next, you need to understand what quality you agreed on. And guided by the following excerpt from SNiP, you can accept work. With a good apartment renovation, as a rule, it is considered as high-quality (I will give notes in parentheses on its example) or, at worst, improved.

Plastered surfaces

Measuring, at least 5 measurements with a two-meter control rail on 50-70 m2 of surface or on a separate section of a smaller area in places identified by a continuous visual inspection (for molded ones - at least 5 by 35-40 m and three per element), work log

vertical deviations (mm per 1 m), mm:

with simple plaster - 3

No more than 15 mm to the height of the room

the same, improved - 2

The same, no more than 10 mm

the same, high-quality - 1 (attach a 2m level to the wall vertically, with this measurement, the deviation of the wall level by the length of the rule should not exceed 2mm)

The same, no more than 5 mm

irregularities of a smooth outline (per 4 m2):

with simple plaster - no more than 3, depth (height) up to 5 mm

the same, improved - no more than 2, depth (height) up to 3 mm

the same, high-quality - no more than 2, depth (height) up to 2 mm (attach the rule arbitrarily in all planes, gaps under the rule, or vice versa, smooth bulges should not exceed 2 mm)

horizontal deviations (mm per 1 m) should not exceed, mm:

with simple plaster - 3

the same, improved - 2

same, high quality - 1

Another important point... Selectively tap the walls with a metal object, such as a door key. In places where the plaster has poor adhesion to the base, you will not hear a thud as it should be, but a feeling of emptiness. You can safely say that such places should be opened and redone at your own expense, this is a clear negligence in work. The same can be said if under the rule there is a hole as thick as a finger. or vice versa, a bump, well, all the norms for these deviations are listed above.