Quality control, defects in plastering. Improved wall plastering: 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 plaster”. As a rule, documents do not have a transcript of a term meaning a certain set of operations.

Often this leads to a misunderstanding of the essence of the work and, as a consequence, to further conflicts between the customer and the manufacturer of the work. Only an accurate idea of \u200b\u200bthe degree of quality of future work will allow you to avoid problems in the repair of housing. This article will help you with this.

Finishing Classes

Russian SNiP No. 3.04.01 / 87 “Finishing and insulation coatings” defines three types of plastering according to its quality:

• simple;
• improved;
• high quality.

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

They regulate the maximum permissible deviations from design values \u200b\u200bor conditions that are accepted between the parties in a relationship by default.

Plaster layers

Before we go on to describe the types of plaster in terms of quality, we will talk a little about the layers of finish. This is important for understanding the subject matter.

First spray the base.

1. Its purpose is to provide reliable adhesion to the wall surface of the following layers. For spraying, a solution having a liquid consistency is used. This makes it possible to clog the roughness of the base, to provide a strong hitch, to 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 having a doughy consistency is used. Its thickness can be 1/2 centimeter.
3. Third layer - nakryvka. It is needed to smooth out small defects and smooth the coating. For him, use a solution of creamy consistency. The layer thickness should be 0.2 / 0.5 centimeters.

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

Types of plaster by quality

1. A simple type of decoration is used in basement, utility, warehouse, attic rooms. In other words, in all non-residential rooms where an absolutely flat wall surface is not required.
2. Improved plastering is needed in rooms that are directly used by humans. This can be residential buildings and apartments, medical, public, educational institutions, etc.

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

SNiP defines the following features of the classes of plaster coating.

1. A simple finish should consist of two mortar layers - spray and soil. Their total thickness should be 2 centimeters.
2. The improved coating is applied in three layers and consists of spray, primer and coatings. The total thickness of the finish should be about 5 centimeters.
3. High-quality class of plaster consists of four layers - spray, two primers and coatings. The total thickness of such a finish should be close to 2 centimeters.

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

High-quality class of plaster is intended for leveling and smoothing the bases, with their further decoration:

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

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

It should be remembered that the optimal order of the product of the described operations is as follows.

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

Related Articles:

Quality Requirements

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

Permissible deviations during work

1. Differences in the plane of the walls from the vertical by 1 meter of their length - 1 millimeter. The entire height of the room is no more than 5 millimeters. The plane of the walls from the horizontal, 1 meter of their length - 1 millimeter
2. Carrying out the work with your own hands, note that the surface of the finish can have no more than two irregularities of smooth outlines of 4 square meters. Their depth or height should not exceed 2 millimeters.
3. Deviations of door and window slopes, arches, pillars, pilasters from horizontal and vertical should not exceed 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 in this case? This must be done using the template-patterns.
5. The width of the slopes from the design value should not deviate more than 2 millimeters.
6. Deviations of rods from a straight axis, between the angles of their intersection and splitting, cannot be more than 2 millimeters.

Coating and base characteristics

The moisture level of stone, concrete and brick walls during their plastering should not exceed 8%. The strength of adhesion (adhesion) of the plaster mixes (in MPa), during internal work, should be at least 0.1. When performing external plastering work, this value cannot be less than 0.4.

Below is the allowable thickness of each of the layers of the finish when laying multilayer coatings (without the use of polymer modifiers).

1. The thickness of the spray on concrete, stone and brick bases is not more than 5 millimeters.
2. The amount of spray on the surfaces of wood (together with the thickness of the shingles) is not more than 9 millimeters.
3. Soil, consisting of a cement-sand mixture, should have a thickness of not more than 1/2 centimeters.
4. The primer layer, laid out of lime, gypsum or lime-gypsum mortar, should not exceed 0.7 / 1 centimeter in thickness.
5. The rough plaster finish should be 0.2 / 0.5 millimeters.
6. The topcoat of the decorative coating should not exceed 7 centimeters.

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

Material Quality Requirements

These provisions are voiced in GOST No. 28013/98. "Mortars" in the section "General tech. conditions".

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

A ready-made plaster mix prepared independently or purchased at a concrete plant must comply with the following characteristics.

1. The solution intended for spraying and priming should pass through a sieve having a cell cross section of 3 millimeters. The mixture for nakryvki or single-layer plaster should 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 exfoliation should not exceed 15%.
4. The water holding capacity of the mixture should be at least 90%.
5. The strength of the coating should correspond to the value laid down in the project.

The plaster mixture must be kneaded on sand having a fractional 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 nakryvki should have a fractionality of not more than 1.25 millimeters.

The stucco mixture purchased at the factory should be accompanied by a document on its quality.

It indicates the following:

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

Work according to the regulatory document

Requirements for the implementation of high-quality plastering are voiced in paragraphs No. 3.1 / 3.17 of SNiPa No. 03.04.01 / 87.

Surface preparation

Prior to plastering, such operations must be carried out.

1. Finished premises should be protected from weathering and precipitation.
2. Equipped with hydro, heat and sound insulation of surfaces, as well as leveling screed floors.
3. Joints and seams between panels and blocks are sealed.
4. The mating sections of the door and window, as well as balcony blocks have been sealed and carefully insulated.
5. Installed windows.
6. Embedded elements are 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 the processed bases not lower than + 10 °. Humidity should be no more than 60%. This temperature must be maintained in the premises constantly not 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 PPR - the project of works for the construction of a building or structure.

Note! It is strictly forbidden to apply plastering on surfaces with areas with efflorescence, rust, bituminous and greasy stains. Dust off the base before laying each of the layers of plaster.

1. The strength of the treated surfaces should not be less than the same amount of finish.
2. The architectural elements protruding beyond the base plane, the mating sections of wooden surfaces with stone, brick and concrete structures, should be plastered along the reinforcing mesh fixed on them. Completely wooden bases need to be trimmed on shields from shingles.
3. Brick, concrete and stone walls constructed using the method of freezing should be plastered only after they have 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 coating the surface with a single layer of plaster, it must be smoothed immediately after application. When using trowel aggregates - after setting the mixture.
6. When laying a multilayer coating, apply each of the layers only after preliminary hardening of the previous one. The soil must be leveled before it begins to set.

Output

High-quality plaster according to SNiPu ensures that during the subsequent installation of the finishing finish and its operation there will be no problems. Having studied the regulatory documents, you can finish yourself or effectively control the work of hired plasterers. By watching the video in this article, you will gain even more useful knowledge.

Theme №42: “Quality control of plastering. Stucco defects. Reasons and their elimination "

Introduction

Currently, there are a large number of engineering survey methods for buildings for various purposes, issued by various organizations. Despite this diversity, they all have one common property - as a rule, they only deal with field surveys of building building structures. This is due to the fact that during the period of the 70-90s of the last century, various industrial enterprises were the customers of such works and the task of field surveys was mainly to determine the condition of the supporting and enclosing structures of buildings. The results of such work were used, as a rule, by the operational services for the liquidation of the emergency state of building structures.

In recent 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 engineering equipment of buildings, and the main customers and consumers of the results of the work are investors and design organizations. In this case, the necessary amount of information can be obtained by conducting only 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 with its own characteristics is placed in the existing volume of the building. In this case, in addition to determining the bearing capacity of the frame for new loads, it is necessary to determine the actual fire safety of the building. Such work is also necessary because of significant changes in the regulatory framework, which requires identifying the compliance of the space-planning and structural 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 existing engineering equipment systems. This is an assessment of the state of communications, inspection of thermal and energy inputs into the building, identifying the compliance of existing heat and power capacities with the anticipated changes in the building.

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

First   - an increase in the thermotechnical properties of building envelopes that meet new, higher regulatory requirements.

Second   - improvement of building engineering systems.

The choice of the optimal solution for the reconstruction of the building with the lowest energy consumption during its operation is achieved by an energy audit - by conducting thermal engineering inspections of building envelopes and engineering systems and by a technical and economic comparison of their effectiveness.

Comprehensive surveys of reconstructed buildings should include the following sections:

Survey of the operational environment;

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

Inspection of engineering equipment systems and energy audits;

Assessment of fire safety of the reconstructed building.

Based on such a wide range of issues addressed by a comprehensive survey of reconstructed buildings, the composition of the survey participants also changes significantly. In this case, the group of examiners should also become integrated, i.e. it should include specialists in the study of the indoor microclimate, engineers in assessing the condition of load-bearing and building envelopes, experts in the inspection of engineering equipment systems and in the fire safety of buildings.

1. Plaster. Destination. A kind of plaster. Quality control of plastering

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

Purpose of plaster.

Plaster has a sanitary, protective, structural and decorative purpose. Sanitary purpose    plastering consists in obtaining smooth 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 prefabricated concrete elements with a clean, smooth surface cannot be plastered. Protective designation    plastering of building envelopes and load-bearing structures is to protect structures from the harmful effects of dampness, increase heat transfer resistance, reduce sound conductivity, and protect against the effects of chemicals. Plaster must meet the climatic conditions of the construction area, fire safety requirements, temperature and humidity conditions of the premises, technological requirements of production, as well as protect building structures from 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 are the following types:

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

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

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

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

Varieties of plaster, depending on the type of plastered surface.

Plastering various types of surfaces requires various materials and methods for the preliminary preparation of these surfaces. Wet stone stucco is usually made of lime or complex mortar when finishing internal brick surfaces and cement mortar on concrete surfaces with preliminary notching with insufficient surface roughness. In both cases, various aggregates and additives are included in the solutions, depending on the purpose and operating conditions of the plastered surfaces. Dry stone stucco is fixed by gluing the back of the sheets with special mastics, which are applied to the base in the form of separate adhesive marks and beacons, as well as with nails to a pre-arranged wooden frame or on screws to special aluminum structures. Wet stucco on wood is made of lime-gypsum mortar with additives. Dry plaster sheets to wooden surfaces are fixed with screws or thin nails with wide hats recessed into the sheet. Plaster on a metal mesh or reinforced plaster is used if it is necessary to create a plaster layer on the slope of the structure to be finished 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 grooves for concealed piping, when creating thickened bastings over 20 mm, when plastering exposed concrete, brick and wooden architectural details (cornices, rods, belts, etc.), when plastering Surface structures of dissimilar materials (wood with brick, concrete, etc.), joints door baskets with walls and partitions. A metal mesh reinforces the plaster, which prevents the appearance of cracks on it along the lines of such joints.

Varieties of plaster according to the method of execution.

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

The disadvantages of wet plaster are the duration and complexity of the execution, the duration of the hardening and drying of the solution, a lot of moisture in the room. All this inevitably extends the term of commissioning of the facility.

The advantage of wet plaster is a monolithic bond with the plastered surface, in which the gaps in the structure are closed and no gaps are formed between the structure and the plaster; monolithic plaster provides seamlessness, the ability to give 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 decoration of both internal and external surfaces. Dry plaster is more individual in relation to the performance of work: its implementation is not associated with a loss of time for hardening and drying; work may be carried out by less skilled workers; the subsequent finishing can be started immediately after upholstering the surfaces with sheets of dry plaster and sealing the joints between them. However, dry plaster is suitable only for finishing 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.

Simple plaster    perform in the basement and attic of residential and public buildings, in non-capital buildings, in temporary structures, in warehouses and non-residential premises, where careful surface treatment is not required. Simple plastering is performed under the "falcon", i.e. a layer of a tent of soil (except for spraying) is leveled by the edge of a falcon. Basting is usually applied in two layers - spray and soil, without hanging and checking the rule, the coating layer is not applied, but wiped the surface of the soil. The angles of window and door slopes, pilasters, pillars are carefully leveled with a trowel. The average total thickness of the plaster coat does not exceed 12 mm.

Improved plaster    It is usually done in residential and public buildings (schools, hospitals, kindergartens, etc.), as well as in special cases in industrial buildings and in the utility rooms of high-class buildings, for plastering building facades without special architectural design. Improved plastering is performed as follows: a spray layer 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 with a thickness of 5 mm in cement mortar and

7 mm with lime and lime-gypsum solutions; 2 mm topcoat with a surface check by rule, without hanging surfaces. The average thickness of the bast is 15 mm. A 2 mm thick coating layer is wiped with plastic, wooden or felt graters and smoothed with rubber or steel trowels. High-quality plastering is carried out in buildings and structures, for the decoration of which high demands are made: theaters, museums, exhibition halls, hotels, high-class residential buildings, etc. The surfaces of walls, ceilings and slopes should be strictly vertical or horizontal planes.

High quality plaster    they are made of a spray layer, one or several layers of soil and coverings with hanging surfaces and installing beacons, the height of which above the plastered surface determines the necessary thickness of the plaster coat. Lighthouses and stamps are made of quick-hardening solutions. The average total thickness of the coating of high-quality plaster is 20 mm.

Quality control of plastering.

Surfaces to be plastered must be thoroughly cleaned of dust, dirt, grease and bitumen stains, and salts protruding on the surface.

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

In the manufacture of plastering, the following requirements must be met:

Permissible thickness of single-layer plaster:

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

From gypsum solutions - up to 15 mm.

The permissible thickness of each layer when installing multilayer plasters without polymer additives:

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

Spray on wooden surfaces (including the thickness of the wood) - up to 9 mm;

Soil from cement mortars - up to 5 mm;

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

Plaster coating layer - up to 2 mm;

Covering layer of decorative finishes - 7 mm.

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

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

With improved plaster, not more than 2 mm (not more than 10 mm for the entire height of the room);

With high-quality plaster - not more than 1 mm (not more than 5 mm for the entire height of the room).

Deviations of the plastered surfaces horizontally (per 1 m):

With simple plastering - no more than 3 mm;

With improved plaster - not 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 (by 1 m):

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

With improved plaster - not more than 2 mm (up to 5 mm for the entire element);

With high-quality plaster - not more than 1 mm (up to 3 mm for the entire element).

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

With simple plastering - no more than 10 mm;

With improved plaster - not more than 7 mm;

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

Deviations of the slope width from the design:

With simple plastering - no more than 5 mm;

Deviation of rods from a straight line between the angles of intersection and uncut:

With simple plastering - no more than 6 mm;

With improved plaster - not more than 3 mm;

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

Roughnesses of surfaces of a smooth outline (on 4 m 2) are allowed:

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

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

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

Cracks, tubercles, shells, dutics, rough surfaces, gaps on the plastered surface are not allowed.

When controlling the quality of wall decoration with sheets of dry plaster, it is necessary to be guided by the following tolerances:

- vertically at 1 m height - no more than 2 mm, and over 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, dots, slopes, pilasters and other details for 1 m of height or length - up to 2 mm, and for the whole element - no more than 3 mm;

- the width of the lined slope is not more than ± 2 mm; the height and depth of the bumps when monitoring with a two-meter rail - no more than 2 mm, sagging in the walls - 2 mm;

- the width of the joints to be sealed between the sheets of dry plaster is not more than 6 mm.

The pasted sheets of dry plaster are respectively prepared and painted or pasted over with wallpaper.

2. Technical inspection of buildings and structures before overhaul and reconstruction. Stucco defects. Reasons and their elimination

Reconstruction   means the reconstruction 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 necessary, since they perform these works in cramped conditions, sometimes in old buildings that are extremely unsuitable for this, in existing workshops. All this complicates the use of existing 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 it 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 \u200b\u200bof the controlled parameters characterizing the operational state, suitability and operability of the objects under examination and determining the possibility of their further operation or the need for restoration and amplification.

The need for survey work, their volume, composition and nature depend on the specific tasks. The reasons for the examination may be the following reasons:

Inspection of buildings and structures damaged by accidents, catastrophes, fires, earthquakes is necessary (the purpose of such an examination is to establish the possibility of further operation of the building and develop measures to strengthen structures);

A reconstruction project is required, and before any reconstruction it is necessary to carry out to provide designers with complete information, even in cases not accompanied by increased loads;

Lack of design, technical and executive documentation;

Changing the functional purpose of buildings and structures;

The need to monitor and assess the state of building structures located close to newly constructed structures;

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

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

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

Overhaul of the facility is planned;

In the event that deformation of the building is detected (as a rule, this is the opening of cracks in the walls), it is necessary to find out whether it is dangerous and whether the building can be operated further;

It is planned to resume construction in progress in the absence of conservation or after three years after the termination of construction during conservation, for which it is necessary to clarify the current technical condition of the unfinished object (sometimes it is impractical to continue construction);

Inspection of buildings in order to monitor their condition during 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;

It is planned to purchase a building or premises in the building, and you need to find out its real condition (a survey is strongly recommended, an error can cost a lot at today's real estate prices);

When creating the executive documentation for “self-construction” (the executive documentation, that is, the project, also requires a description of the current technical condition of the facility), if necessary, conduct measurements to compile measurement drawings.

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

Stages of conducting 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 examination;

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:

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

Selection and analysis of design 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 surveyor. The terms of reference are approved by the customer, agreed by the contractor and, if necessary, by the design organization - the developer of the draft task.

Preliminary (visual) examination:

A continuous visual inspection of building structures and the identification of defects and damage by external signs with the necessary measurements and their fixation.

Detailed (instrumental) examination:

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

Instrumental determination of defect and damage parameters;

Determination of the actual strength characteristics of the materials of the main supporting 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 examined structures, taking into account the influence of deformations of the soil base;

Determination of the real 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 according to the results of the survey;

Office processing and analysis of survey results and verification calculations;

Analysis of the causes of defects and damage to structures;

Drawing up a final document (act, conclusion, technical report) with conclusions 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 object of study, its condition and tasks defined by the technical task.

Reporting Results   . Based on the results of the survey, a report is prepared 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.

According to the results of the survey, the final document contains plans, sections, statements of defects and damages or a diagram of defects and damages with photographs of their most characteristic ones; crack location schemes in reinforced concrete structures and data on their disclosure; the values \u200b\u200bof all controlled signs, the definition of which was provided for by the technical task or program of the survey results of verification calculations, if their implementation was provided for by the survey program; assessment of the condition of structures with recommended measures to strengthen structures, eliminate defects and damage, as well as the reasons for their appearance.

This list may be supplemented depending on the condition of the structures, reasons and objectives of the survey.

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

Stucco defects.

Internal plaster

Often the plaster is made very "skinny." She badly grasps with the surface of the wall, dusts if rubbed with her hand. Paint or wallpaper is not

  hold on to it (Fig. 1).

Figure 1. Wallpaper rips the “skinny” plaster from the wall. 1 - wall; 2 - wallpaper; 3 - torn off plaster; 4 - cracks; 5 - baseboard; 6 - floor covering; 7 - reinforced concrete floor

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

When the plaster is very “greasy”, i.e. it has more binder than necessary, the plaster also turns out to be of poor quality - it is cracking. Moisture penetrates 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 “oily” plaster. 1 - cracked plaster; 2 - primer; 3 - floor covering; 4 - wall; 5 - painted surface; 6 - reinforced concrete floor

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

Gypsum mortar must not be applied to the concrete surface. Cement and gypsum enter into a chemical reaction with each other, the plaster swells, and then falls away, the gypsum penetrates the surface of the wall and destroys it. To avoid this, a lime mortar of 0.4 cm thickness is applied to the wall. Gypsum does not come into contact with cement or improved mortar. It is completely wrong to plaster with lime mortar on gypsum, as the first one shrinks when it dries, and the second one expands. At the same time, they peel off from each other and the 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 - flooring; 5 - reinforced concrete floor

Often, internal plastering is damaged during electrical work. Before plastering, the wires or wires themselves are placed in grooves made in the walls and fixed with gypsum. In the same way, wooden inserts for hooks for hanging chandeliers are fixed, since the gypsum mortar quickly seizes and gains the necessary strength. This method is used in electrical work, but it is often used to secure the wiring without taking into account the foregoing in relation to reactions that occur

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

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

When installing heating equipment for fastening to the walls of heating pipelines or when wiring them through floors, gypsum is also used. The biggest mistake is made when the heating pipes are laid in a wall or ceiling without casing sleeves. A bricklayer closes the holes, but the stucco is held here only until the heating begins. Under the influence of temperature, the heating pipes change their

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

Figure 5. Movement of the heating pipes causes cracking. 1 - cracks in the plaster; 2 - heating pipes; 3 - plastered surface; 4 - flooring

Along with cracks from thermal expansion, when fixing with a gypsum mortar, 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 sleeves prevents movements leading to cracking, but, however, the sleeves themselves are fixed with plaster. Since the bushings are made of metal, they are also susceptible to corrosion (Fig. 6).

  Figure 6. Fastening heating pipes using gypsum mortar. 1 - casing sleeve; 2 - heating pipe; 3 - a collar; 4 - horizontal casing sleeve; 5 - gypsum solution; 6 - reinforced concrete floor

The plaster applied to the walls after some time hardens and becomes strong. Accelerating the drying or hardening of the plaster often causes cracks, leads to its destruction. It is necessary to wait until the bottom layer of plaster has hardened, otherwise after applying the second layer both of them may fall off the wall. Do not dry plaster, including central heating. This leads to its cracking and falling. To dry the plaster, not only heat is required, but also fresh air, which contains the carbon dioxide necessary for setting. If it is not enough, then the plaster dries, but does not harden. If the solution also contains cement, it also cannot harden, since moisture evaporates quickly when dried. Accelerated drying of the plaster is possible only with good air exchange.
  When replanning, they often use a brick that was already 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) gets into the new masonry of walls, this causes various changes in the plaster, brown spots appear on the surface, damaging whitewashing, and sometimes wallpaper. Correcting the situation is possible only by replacing the brick. The surface of the brick wall before plastering is moistened, because the absorbent brick absorbs the water necessary for setting from the mortar, and the plaster becomes unusable, cracking.
  It is not recommended to plaster directly on a dusty surface, since dust interferes with the adhesion of the mortar to the wall. It is necessary either to eliminate pollution from the surface, or to make the spray of cement mortar a thin layer (Fig. 7).

Figure 7. Plaster falling from a dusty surface. 1 - wall; 2 - application of liquid cement milk; 3 - surface of the wall with cement milk applied to it; 4 - coating the first layer of plaster; 5 - wiped surface

Stucco adheres well to a brick wall, as a rule. The concrete surface is smoother, especially if you use metal or wooden formwork from planed boards, and less moisture-resistant than brick. According to technical standards, a thin layer of liquid cement milk is sprayed onto the concrete surface before plastering, giving the surface the desired roughness. If this is not done, especially on precast concrete floors, then plaster

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

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

When planning houses in ceilings, metal beams are often used, which are processed before plastering. For this, a concrete layer of 2-3 cm thick is applied from below to the beam on a metal mesh that holds the plaster well. The inner surfaces of the sewer wells are plastered with cement mortar. If such plaster does not provide normal care, then it will fall off. Cement plaster is kept moistened for at least a week (spray water on the surface or cover it with wet burlap). Cement plaster cracks when the surface is smoothed with a metal smoothing. In this case, a crust consisting of one cement is formed on the surface, the degree of shrinkage of which is higher than the inner layers, as a result of which it cracks and disappears. The plaster remains in place where it is constantly moistened. When they make reconstruction in the house or build up an attic, they often plaster wooden surfaces. The plaster, however, does not stick to the wood and in order to do this, it is necessary to sheathe the walls with one or

  two layers of shingles (Fig. 9).

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

The internal plaster falls off if it freezes during application or is applied to a frozen wall.

Stucco defects occur in the form of blisters, cracks, peeling, etc., and occur for various reasons. To get high-quality plaster, it is necessary to take measures to eliminate these defects.
  Dutiks - the appearance of swollen places on the surface of the plaster. In the center of each swollen place there is a white, or yellow dot, or yellow spot.
  The stucco peeling and swelling occurs because the plastering was carried out on wet surfaces or because after plastering they were subjected to constant wetting. Most often this happens on calcareous and calcareous-gypsum plasters.

Different types of cracks can be classified as follows:

Cracks due to 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 ratio of stresses and loads. In this case, the plaster may crack throughout the 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 due to the condition of the base under the plaster. Such cracks occur at the base as a result of deformation. In this case, we are also talking about cracks that arose due to 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 due to the construction of the building. Here we are talking about developing cracks that arise as a result of settlement and movements of the structure itself. Such cracks may occur due to environmental changes. For this reason, such cracks should be classified as “dynamic” (heavily loaded).

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

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

Hair cracks. Hair cracks are characterized mainly as randomly located, arising as a result of aging of the material, exposure to atmospheric stresses under conditions of temperature changes, moisture, temperature deformation during operation. If moisture penetrates 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 crack can develop into conditionally static.

Deadlock cracks. Deadlock cracks are characterized mainly as horizontally passing (with a bend down) cracks. In the region of the lower edge of the crack, void formation is possible.

Deadlock cracks occur in a plastic, not yet hardened layer, namely:

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

With poor adhesion of the plaster coating to the base;

With too long and intense grouting of the plastered surface;

If the texture of the mortar is too soft.

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

Shrinkage cracks type B. Shrinkage cracks of type B also appear in the form of a grid or look like branches and are designated as cracks "Y". Such cracks can reach the base. Such cracks may occur if:

The base and plastering system are incompatible;

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

There is an incompatibility of materials inside the plaster system;

The aging period (curing time) is not respected;

Too fast 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, usually extending 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, there is a rupture of other sections of the base.

Cracks in the joints and seams. As the name says, these cracks represent a uniform picture of cracks located at the joints and filling joints of panels or at the seams of the masonry of the enclosing structure, and are identical with them in the form of formation.

The most important causes of this type of crack are:

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

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

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

Reasons and their elimination

There are various causes for cracking. Cracks may occur:

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

If the strength level and the field of application do not match or due to a violation of the particle size distribution curve, for example, during mechanical application, when light impurities are milled;

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

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

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

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

Whenever there is any deformation, internal stresses arise that exceed the internal strength of the plaster coating, the likelihood of cracks on the coating is especially high. At the same time, accumulations of the binder on the surface, the mismatch between the strength of the materials and the field of application, the strong swelling of the base under the plaster as a result of thermal exposure or the penetration of moisture and its shrinkage, as well as improper preparation of the base under the plaster, are essential.

Cracks, delamination and the formation of voids as a result of surface swelling and too high internal stresses in a very hard plaster coating at the boundary of the masonry.

The exact characterization and classification of cracks on the plaster is a particularly 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 the cracks, we can draw a conclusion about the causes of their occurrence in order to further correctly classify cracks and propose appropriate measures for their elimination or repair.

Table 1 shows the defects of the plaster and how to eliminate them.

Table 1. Plaster defects, causes of their appearance and remedies

	Reasons for their appearance	Precautionary measures and solutions
Surface dutiks	The presence in the solution of small particles of non-quenched lime	Soak the lime dough until the lime is completely extinguished. Stir the solution thoroughly. To correct, beat off and clean the damaged places where the dutics appeared, and seal them with a solution flush with the surface of the plaster
Insufficient strength	Weak solution due to insufficient or poor quality binder or high contamination of sand	The compositions and brands of solutions, depending on the type of surfaces, the purpose of the premises and the humidity in the process of their operation, must comply with the accepted data. The quality of the sand must comply with GOST 8736. Insufficiently durable plaster, revealed after tapping, is beaten with a percussion instrument, cleaned and plastered again with a quality mortar with appropriate preparation of the base
Surface cracks	Using too greasy or poorly mixed solutions	When preparing solutions, properly measure the binder materials and aggregates and mix them well
	Fast drying of plaster under the influence of strong through winds and high temperature. Application of thick layers of mortar to freshly applied uncured 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.
	The absence of a metal mesh or weaving of wire along nails at the interfaces between structures of dissimilar materials	Nail strips of metal mesh at the junctions of wooden parts of buildings with brick, concrete or plaster concrete structures. To correct, fill out cracks and cracks, moisten these places well with water, grease them with a solution and wipe them. In places of interfacing of structures of dissimilar materials, beat off the plaster, clear these places, nail strips of metal mesh or braid with wire over nails and plaster again
Swelling and shit	Plastering on wet surfaces or permanent wetting after plastering, especially when using lime and lime-gypsum mortars	Before plastering, moist places must be well dried. To correct, repel the plaster in the places of expansion, clear these places and plaster them again
Rough surface	Application of a coating layer from a solution prepared in coarse sand	Apply a mortar prepared on strained lime and sifted sand to the coating layer. Filter the coating solution. To correct, grind the plaster with a solution prepared on fine sand and filtered through a sieve with 2 mm holes
Exfoliation	Application of the solution on a contaminated or dry surface not moistened with water, or on dry layers of a previously applied solution	The surfaces of brick, concrete and other structures should be thoroughly cleaned of dust, dirt, grease stains, as well as salts protruding on the surface, and moistened with water. The subsequent layers of the plaster coat should be applied immediately after setting the previous layer, if the last is made of lime-gypsum, lime-cement or cement mortar, and after the whitening of the previous layer made of lime mortar
	Subsequent layers of the solution are applied to less durable previous ones.	The subsequent layers of the solution are applied to the stronger previous ones. To correct, discard exfoliating plaster, thoroughly clean, subject to the above conditions
Surface roughness	Stucco made subfloor without surface check by rule	Check the surface with a rule of 2 m in length. In places of recesses, make additional spraying and wipe. Peel off the hillocks with a trowel, spray and wipe.
Granular surface texture and circular stripes	Poorly grouted spray. The solution is prepared on coarse non-sifted sand.	Make an additional spray of a solution prepared on fine sifted sand and rub the surface.
Surface sinks	Preparation of mortar on non-extinguished lime	Wet the surface several times within two weeks with water. After the surface dries, spray on the surface and wipe it.
Greasy and rusty stains	Pollution of the mortar, the caps of the nails of the dry plaster are not proliferated.	To clear places with spots on the entire depth of the layer of plaster and plaster again; peel off the caps of nails from rust and proliferate.

3. Expert examination of buildings and structures

An expert examination of buildings consists of the following steps:

Preparatory, general and detailed examination of the object;

Calculations of strength, stability and deformation of load-bearing structures and buildings, structures in general;

Drawing up a technical report.

At the preparatory stage, it is necessary to study archival materials, the standards by which the design was carried out, collect source data and illustrative materials.

The source data for the work is:

Terms of Reference with a certificate of the expiration of the estimated life of the building;

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

The act of the last general inspection of the building carried out by the maintenance service (the absence of the act is not a basis for non-performance of work);

Information about the construction site (subsidence soils, the availability of part-time jobs, etc.), in the absence of such data, the organization conducting the survey must obtain them independently;

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

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

Establish a structural diagram of the building and identify the location of the supporting structures in plan and height;

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

Designate locations for openings, openings, sounding of structures to obtain reliable (at a level not lower than 0.95) data;

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

To establish the presence of filled ravines, landslide zones and other dangerous geological phenomena near the building;

Assess the location of the building in the development of the neighborhoods from the point of view of backwater in the smoke, gas and ventilation ducts.

A detailed examination is carried out to clarify the structural design of the building, the size of the elements, the condition of materials and structures in general.

In a detailed examination, it is necessary to perform work on opening structures and joints with measurements, taking samples, checking and evaluating deformations, testing selected samples, and determining the physicomechanical characteristics of structures, materials, soils, etc. All types of work should be carried out using tools, instruments, equipment for testing.

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 examination revealed the presence of freezing and getting wet places in the walls of the building, then there is a need to perform thermal engineering calculations. The results are taken into account when developing recommendations for repair activities.

An expert survey technical report should contain:

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

The history of the structure;

Description of the surrounding area and building plot;

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

Drawings (including measurement) of plans and sections;

Marking drawings of structures indicating the location of the autopsy;

Defective statements of all structures and autopsy sites, indicating the amount of physical wear and tear;

Thermotechnical calculations (if necessary);

Calculation of current loads and verification calculations of the foundation, foundations and supporting structures;

The scheme of the plan of the building and the 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 about seismicity and displacement trough;

Determination of physical deterioration of the building as a whole;

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

Building foundations have a physical depreciation of 60% or more, if signs of their deterioration are characterized by the following defects:

The curvature of the horizontal lines of the walls;

Draft of individual sites;

Distortions of window and doorways;

Complete destruction of the base;

Significant bulging soil.

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

Study of soil by drilling;

Opening of control pits;

Checking the availability and condition of waterproofing;

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

Verification calculations of the bearing capacity of the 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 the foundations of buildings are established taking into account the joint work of the building and base structures.

The number of exploratory wells is determined according to table 6CH of the Republic of Kazakhstan 1.04-04-2002.

Control pits for inspection of the structure, size, material of the foundations suit 2 ... 3 per building. Pits are torn from the outside or inside, depending on the convenience of opening.

The pits are torn below the base of the foundation by 0.5 m. If loose, peat, 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 soft 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.

A survey of the foundations and foundations within the open pit is carried out as follows:

They 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 a mechanical determination of the brand of stone and mortar;

Samples of soil and masonry material are taken for laboratory tests;

Establish the presence of waterproofing.

To determine the physicomechanical characteristics of soils, it is necessary to select rocks with a broken and undisturbed structure. Moreover, in laboratory conditions determine the density, bulk density and soil moisture. If necessary, hygroscopic humidity, porosity, particle size distribution, ductility, water resistance, etc. can also be determined.

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 horizontal and vertical lines of walls;

Mass destruction of masonry, blocks or panels;

The presence of temporary fixtures;

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

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

Weathering of joints to a depth of more than 40 mm;

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

Rotting wooden walls.

A detailed examination of the walls, columns and load-bearing partitions produce:

Description of identified structural defects and their assessment;

Mechanical determination of the strength of the material of construction;

Laboratory test of material strength;

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

Thermotechnical calculation.

Verification calculation of structural strength is carried out in accordance with SNiP II-22-81 on the bearing capacity, on the formation and opening of cracks, deformations.

The material of the stone walls is determined by control sounding. For this, bolts with a diameter of 16 ... 20 mm and electric drills are used.

The strength of the wall material at the inspection site can be determined using the hammers of Fizdel, Kashkarov or the TsNIISK device. 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 mortar spalling 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 SN RK 1.04-04-2002).

The signs characterizing the wear of 60% or more of prefabricated reinforced concrete floors, ceilings from two-shell rolling panels and from prefabricated reinforced concrete flooring, wooden floors, are as follows:

Deflections, sometimes falling concrete of the lower slabs;

Exfoliation and exposure of the ribs of the upper plates;

Multiple deep cracks in the slabs;

Displacement of plates from the plane;

Deflection of double-shell reinforced concrete panels more than 1/50;

Deflections of reinforced concrete flooring 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 reinforcement over 10% of the cross section;

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

Severe decay of wood;

Deflection of wooden beams and girders.

When instrumental examination, a preliminary inspection is carried out to establish the material and the structural scheme of the floors, a visual determination of the places of deformation.

The determination of the reinforcement section of reinforced concrete structures, the location and section of metal elements in vaulted ceilings is carried out using ISM devices or a ferroscope.

During the examination should be determined:

Locations and sizes of load-bearing structures;

Spans of beams and runs, the distance between them.

The strength of the overlap material is determined on the samples by laboratory analysis, as well as during the examination of the Fizdel and Kashkarov hammer, the TsNIISK pistol and the UKB-1 ultrasonic device.

Verification calculations of ceilings are carried out to establish the actual stresses in the material of structures caused by current loads, taking into account working 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 test the strength characteristics of floor elements, tests with a test load can be carried out.

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

The temporary load q BP is taken 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 *.

Deflections of the floors are determined by the P-1 deflection meter, as well as by the level with a special nozzle.

To determine the strength characteristics of the material of the floors, an autopsy is performed, the number of which is prescribed depending on the area being examined (table 16 SN RK 1.04-04-2002).

Balconies (loggias) in the presence of deflections of plates more than 1/100 of the span, cracks more than 2 mm, buckling of walls more than 1/150 of their length are referred to the group of emergency structures.

When instrumental examination of balconies is carried out: preliminary inspection, performing autopsy, establishing the nature of deformations, testing structures with a test load, performing calibration calculations. Depending on the material of the construction of the balconies, the strength and deformability of their elements are calculated in accordance with SNiP 2.01.07-85, SNiP 2.03.01-84 *.

If necessary, test the balconies with a test load, similar to the tests of floors. At the same time, the design schemes of the balconies and the stresses depending on them arising in the supporting structures from the existing loads are taken into account.

Instrumental inspection of roof elements is carried out similarly to methods of inspection of ceilings, if there are more than 2 mm cracks in building trusses or balconies, plate or beam deflections are more than 1/100, and plate damage on an area of \u200b\u200bmore than 20% is assessed as emergency. During the inspection, the type and material of the supporting structures are established, laboratory analysis of the strength characteristics of the material of the supporting structures is carried out, verification tests of the stresses in the roof elements from the existing loads are performed.

In the presence of deflections of up to 1/150 span, local damage, cracks in the marching plate mates, deflections of steel stringers with weakening of their ties with the platforms, damage to the notches in the construction of wooden stairs, rotted wooden elements, the state of the stairs is classified as emergency. In the process of instrumental inspection of the stairs, an external examination of the supporting structures is performed, if necessary, an autopsy is performed with sampling of materials for laboratory analysis, 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 the level with a special nozzle. The measurements obtained are compared with the maximum allowable deflections established for the emergency state of this design.

The structure of the study of wooden supporting structures includes determining the quality of wood by drilling with an electric drill or a hollow drill, which allows you to remove a column of wood for judging the change in color, strength of the wood, and also to establish the boundaries of damage.

The methodology for determining the deformation of the foundations and foundations of buildings includes the following work.

Before starting work, an on-site reconnaissance is carried out.

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

Based on the results of reconnaissance, the following should be compiled:

Brief characteristics of home ownership and buildings;

Description of the characteristics and condition of soils;

Description of the bookmark places of the geodetic signs, the rationale for their choice;

An approximate diagram of the intended measuring network;

The presence of cracks and the location of the beacons.

After this, a work program is drawn up to determine the deformations of the foundations and foundations of buildings.

The work program consists of a brief explanatory note to which a work schedule is attached.

The explanatory note shall indicate:

The goals and objectives of the observations;

Engineering and geological conditions of the foundation;

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

Instruments and methods of measurement;

The procedure for processing measurement results;

Compilation of a report on the results of observations.

Monitoring precipitation and deformation of the bases and foundations is terminated if, during three measurement cycles, their value fluctuates within the specified measurement accuracy.

Measurements of vertical displacements (precipitation, rises, etc.) are divided into three classes, which are characterized by the accuracy of the measurement - the value of the standard error of two measurement cycles:

for grade 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.

The placement, design and installation of the original benchmarks is performed as follows:

Before starting work on the measurement of sediment, a ground geodetic sign is established, which is laid below the freezing depth;

Soil 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 soil benchmarks;

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

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

When laying wall frames, it is necessary that the buildings have no visible deformations and should be built 5 or more years before laying the signs.

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

Stamps are set at approximately the same level, placing them on the corners of the building, at the junctions of the transverse and longitudinal walls;

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

Each brand is assigned a number.

Measurement of sediment 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 suspension is not allowed more than 2;

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

After performing a closed stroke, its residual is calculated; it should not exceed the permissible residual f n.

Processing of measurement results is as follows:

At the end of field measurements, the excess between marks and marks is calculated and a leveling moves chart is drawn up, on which the calculated excesses, obtained and allowable residuals are written; rounding is carried out to the following values:

Excess 0.1 mm;

Marks 1 mm;

Draft 1 mm;

The precipitation of the foundations under each brand is 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, the number of its precipitation in mm is written under the number of each brand;

Based on the statement of sediment, statements of the average weekly, monthly average precipitation rates are made;

In vivo, hydrostatic leveling is used to determine sediment.

Observation of cracks is carried out, observing the following conditions:

On each crack in the place of greatest opening a lighthouse is installed;

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

The location of the cracks is schematically applied to the drawings of a General view;

For each crack, a schedule for its disclosure is made;

On cracks and lighthouses, in accordance with the inspection schedule, draw up an act; the act shall indicate:

Date of inspection;

Surnames and positions of inspectors;

Drawings with the location of cracks and lighthouses;

Information on the state of cracks and lighthouses during inspection and replacement of collapsed lighthouses with new ones;

Information about the absence or presence of new lighthouses.

References

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. A comprehensive methodology for the examination and energy audit of reconstructed buildings. - M.: Gosarkhstroykontrol, 2000.

5. МРР - 2.2.07-98 Methodology for conducting a survey of buildings and structures during their reconstruction or redevelopment. - M .: State Unitary Enterprise "NIAC", 1998. - 28 p.

12. RDS RK 1.04-07-2002 Rules for assessing the physical depreciation 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 solutions. Test methods. - M .: Publishing house of standards, 1986.

The thickness of the plaster should correspond to the following data:

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

Quality requirements for various types of plaster.

On even 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. a grouted coating. On surfaces made of straw, reed and fiberboard, the thickness of the plaster should not exceed 20 mm without additional preparation. On wooden surfaces, it is advisable to install a layer of plaster with a thickness of 20 mm or at least 15 mm from the level of the output groove, since thinner layers of mortar are easily torn from warping of stuffed drapes, and the tear itself is “imprinted” on the surface of the stucco.

Plaster should adhere firmly to the surface, not peel off; to have a well-worn surface, without external defects. The accuracy of the plaster being performed is checked by a 2-meter rule (rail). For this, the rule is applied to the surface of the plastered wall in different directions: vertically, horizontally, diagonally. If the deviations are more than the norms given in table. 1, they are eliminated (cut off the solution or additionally impose).

The vertical and horizontal position of a simple plaster is controlled by a rule or a cord, i.e., pulling the cord indented over the thickness of the plaster and arranging marks and beacons under this cord. For improved and high-quality plaster surfaces are hung up, stamps and beacons are arranged.

Plaster quality

  Plaster Quality Indicators

Indicators	Tolerances for the quality of the plaster.
	Plain.	Superior.	High quality and decorative.
Roughnesses in the surface are detected when a 2 meter long rule is applied.	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.
Surface deviations from the vertical.	15 mm the entire height of the room.	2 mm. 1 meter high, but not more than 10 mm. the entire height of the room.	1 mm. 1 meter high, but not more than 5 mm. the entire height of the room.
Surface deviations from the horizontal.	15 mm to the whole room.	2 mm. 1 meter length, but not more than 10 mm. the entire length of the room or part of it is limited by girders, beams.	1 mm. 1 meter length, but not more than 7 mm. the entire length of the room or part of it is limited by girders, beams.
Deviations of husks, oats, window and door slopes, pilasters, pillars from vertical and horizontal.	10 mm for the whole element.	2 mm. per 1 meter of height or length, but not more than 5 mm. on the whole element.	1 mm. by 1 meter of height or length, but not more than 3 mm. on the whole element.
Deviations of the radius of curved surfaces from the design value (checked by the pattern) mm.	10 mm.	7 mm.	5 mm.
Deviations of the width of the plastered slope from the design, mm.	Not verified.	3 mm.	2 mm.
Deviations of rods from a straight line between the angles of intersection and pockets, mm.	6 mm.	3 mm.	2 mm.

Textbook Stuccoing. Shepelev.A.M.

Stuccoing is a very important stage of finishing work, on which the coziness and beauty in your home directly depend. So that the living room and bedroom always delight the eye, it is necessary to pay special attention to the choice of plaster and the builders who will perform the decoration of the premises. In this article we will focus on what requirements building mixtures must meet and how to check the quality of work performed.

First, a few words about the quality characteristics of the plaster. It 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 material from shedding during operation, and water resistance helps to avoid serious problems in case of flooding the apartment. In addition, quality is characterized by elasticity. It is no secret that constant soil movements cause small deformations of load-bearing structures. If you decide to save and purchased cheap finishing materials, then do not be surprised if in a few years they begin to crack.

Now about the requirements for applying plaster. By putting it on the walls, you need a room and prepare the surface. Old for walls are removed, as, however, and old plaster. After that, all surfaces are thoroughly cleaned of dust, stains of various origin and other contaminants.

The solution is applied evenly over the entire wall, the layer should not exceed 20 mm. Checking 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 bumps, cracks and potholes are the basis for claims to builders.

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

You should check the evenness of the walls. To do this, take a rule at least 2 meters long and attach to the plastered surface. If the decoration was done by professionals, then the gap should 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 on 2.5 m of the surface.

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

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

To check the evenness of the wall, use a vertical plane!

There are two methods for assessing the evenness of the wall (checking for the presence of hollows and bumps on the wall surface):

1. Checking flatness over a large area of \u200b\u200bthe wall.

2. Checking the evenness in a small area.

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

1. Check the evenness over a large area of \u200b\u200bthe wall.

This technique is useful in assessing the volume of plastering, but can also be used when checking at the end of plastering and painting. As a rule, before the plaster, the differences in the wall are quite large and so noticeable - this technique will allow you to quantitatively estimate the amount of work to level the wall with plaster.

It is necessary to include the vertical plane of the linear laser level (plane builder), set the level at the edge of the wall so that the vertical laser plane runs parallel to the wall. To do this, mark the floor along the wall at the same distance from walls 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, namely, a plane parallel to it). If a wall section without a laser beam appears on the wall opposite from the level, then the beam is interrupted at some point by the convex part of the wall - it is necessary to move the laser level 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), it is necessary to take a steel or wooden meter with a millimeter scale without moving parts (roulette does not fit precisely because of the movable hook that almost every roulette is equipped with).

We select a vertical section of 1-2 cm and put the meter perpendicular to the wall - the free end of the meter abuts the wall at an angle of 90 degrees to the wall surface, and the laser beam appears on the roulette 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 necessary.

Now the data for this vertical section can be compared with the data for the vertical section of the wall through 40 cm or in meters.

We compare the obtained dimensions and get an idea of \u200b\u200bthe 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 finished, the irregularities, as a rule, are 1.2.3 mm and it is not always convenient to search for them according to the first technique with a ruler.

Particularly visible are the irregularities on the walls for painting, painted in dark and which direct sunlight falls at an angle ... The same method is used to assess the evenness of the wall after the finish before painting and gluing the wallpaper.

This technique is not difficult to apply. First we need to visually mark a square on the floor (which we will measure) (draw it with chalk or mark it with some objects) - we need it in order to 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 mark the points C, D, E by dividing the segment between the wall and the previous marked point in half (we get the angles 45/2 \u003d 22, 5; 22.5 / 2 \u003d 11.25; 11.25 / 2 \u003d 5.62):

In this case, when the plane falls on the wall, it will be flat at any angle only when the wall is perfectly flat! With irregularities, 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 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. We will clearly demonstrate this in Figure 5:

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

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

When the angle of incidence of the beam on the wall changes, the ratio of A1 to the desired value of 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" \u003d X

Here are the values \u200b\u200bof the cotangent of the angles that we used in the calculations:

And this is an example of calculating irregularities in millimeters, depending on what angle the beam falls on the wall:

Source: www.laserpribor.ru

How to check the plaster?

Instruction manual

.1

Before deciding whether to replace the plaster or not, it is necessary to check its strength, how well it adheres to the wall. Based on the results, Mono will draw the appropriate conclusion: it is necessary to plaster the wall, leave it in the state in which it is present or there will be enough minor cosmetic repairs in some areas.

.2

The easiest way to check the plaster is to use a scraper or trowel. It is necessary to take the appropriate tool and hold it on the surface, in those places where the cement crumb begins to crumble, you need 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 with them, then such coverage is no longer subject to partial correction and requires a complete replacement.

.3

To determine the strength of the plastered surface, you can take a simple hammer and tap it with a handle on the surface. In places where the coating is unreliable, a dull response will be heard, they need to be noted with something. If there are many such places, it is recommended to completely repaint the wall.

.4

You can also dry the surface and see if there are any damp spots on it. As a rule, they will differ in a characteristic color shade, it will be darker. In this case, it is necessary to plaster not only the wet section, 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, but to take and replace the entire coating. Grease stains may appear on the plaster, the cause of which often lies much deeper - in the wall itself. In this case, it is recommended to chip on the wall and apply a new solution.

.6

Cracks on the plaster are recommended to be checked with a small sharp object. Without pressing hard, they need to be drawn along all sections of the wall, when a crack appears, the object will jump or, vice versa, will sink into it. Then the crack needs to be enlarged on its own and covered with a fresh solution. It is worth noting that all work should be done on dry plaster, so it needs to be dried beforehand.

Stucco walls - a question on the quality of work - discussion on the forum ngs.sdom 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 excerpt from SNiP below, you can take work. With a good apartment repair, as a rule, it is considered as high-quality (I will give notes in parentheses for its example) or, at worst, improved.

Plastered surfaces

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

deviations from the vertical (mm per 1 m), mm:

with simple plastering - 3

Not more than 15 mm to the height of the room

same, improved - 2

The same, no more than 10 mm

the same, high-quality - 1 (you set the 2nd level to the wall vertically, with such a measurement, the deviation of the wall level by the length of the rule should not exceed 2 mm)

Same, no more than 5 mm

irregularities of a smooth outline (on 4 m2):

with simple plastering - 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 (you put the rule randomly in all planes, slots 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 plastering - 3

same, improved - 2

same, high quality - 1

Another important moment ... Selectively tap the walls with a metal object, for example, a door key. In places where the stucco has poor adhesion to the base, you will hear not a dull thud as it should be, but a feeling of emptiness. You can safely say such places to be opened and redone at your own expense, this is a clear negligence in the work. The same thing can be said if a finger-sized hole is found under the rule. or vice versa, well, all the rules for these deviations are summarized above.