Quality control, plastering defects. The quality of the plaster, what are the standards for plastering

Plaster can be simple, improved and high quality. Contrary to popular belief, these definitions do not refer to the quality of the material, but to the technology of work and finishing characteristics, which are regulated by the requirements and rules of SNiP and GOST. Consider the differences between improved plaster and other types of plaster finishes and the requirements that it must meet.

Differences between different types of plaster

Tolerances for improved plaster

In accordance with SNiP 3.04.01-87, plastered surfaces may have deviations that are not a violation of the norm:

• from the vertical and horizontal, the coating may have a deviation of no more than 2 mm per 1 m of length;
• for the entire height of the wall, the surface can be deflected by no more than 10 mm;
• slopes of windows and doors, pillars, pilasters, husks can be deviated by no more than 2 mm from the vertical and horizontal per 1 m of length;
• the radius of curved surfaces can be deviated by 7mm from the value specified in the project (control is carried out using a pattern);
• the width of the slope may differ from the design by 3 mm.

Important! SNiP for improved plaster does not allow the presence of delaminations, cracks, shells, efflorescence on the surface, as well as visible traces of the tool that was used for grouting.

Requirements for the quality of the used plaster compositions

The quality control of the used material and mortar is carried out on the basis of GOST 28013-98 “Construction mortars. General technical conditions".

According to GOST, the solution for improved plaster must meet the following requirements:

1. The solution intended for spraying and soil must pass through a mesh with a mesh diameter of 3 mm.
2. The solution for the coating layer must pass through the mesh, which has a mesh size of 1.5 mm.
3. The sand used to prepare the mortar must contain grains, the size of which does not exceed 2.5 mm in solutions for soil and spray and 1.25 mm for finishing.
4. GOST also regulates such technical specifications such as mobility, exfoliation, water retention and strength.

An additional requirement of GOST is the presence of a document in the solution, which indicates:

• date and time of preparation;
• brand of solution;
• quantity;
• mobility;
• binder component;
• standard.

Quality control of plaster works

Control over compliance with the requirements of SNiP and GOST is carried out at three stages: at the stage of preparation, in the process of work and at the stage of inspection and acceptance of the finished base.

For control on preparatory stage necessary:

• check the quality of the solution;
• determine the humidity of the walls and temperature;
• make sure the walls are cleaned of dirt.

In the process of performing plastering works, control of verticality and horizontality, as well as the quality of the resulting coatings, is carried out.

On last step control consists in checking the adhesion strength of the dried mortar with the wall and the quality of the surface that has undergone sanding.

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

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

Finishing classes

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

• simple;
• improved;
• high quality.

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

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

Plaster layers

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

First, the base is sprayed.

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

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

Types of plaster by quality

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

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

SNiP defines the following features of plaster coating classes.

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

Note! The instruction says that the application of improved and high quality plaster must necessarily be carried out along the guide beacons. They are installed on the walls before the main work and can be made from mortar or be finished metal profiles.

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

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

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

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

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

Related articles:

Finish quality requirements

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

Permissible deviations in the implementation of work

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

Coating and substrate characteristics

The humidity level of stone, concrete and brick walls during their plastering should not exceed 8%. Adhesion strength (adhesion) of plaster mixtures (in MPa), at internal works ah, must be at least 0.1. When performing external plastering works, this value cannot be less than 0.4.

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

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

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

Requirements for the quality of materials

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

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

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

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

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

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

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

It states the following:

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

Carrying out work in accordance with the regulatory document

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

Surface preparation

Prior to plastering, such operations must be carried out.

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

Main works

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

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

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

Conclusion

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

A cheap and reliable way to clad the inside and outside of a house is traditional wall stucco. This method is indispensable for interior work. Modern finishing technologies and a wide range of products improve the quality protective coating walls. How to avoid mistakes during work and choose the right materials and tools.

How to check the quality of plaster and find out its composition?

Determining what composition the old wall plaster is made of is very simple. If she has grey colour- it is cement; yellowish-white or chalk color - gypsum, white-gray in lime-cement plaster. To determine the quality of the wall you need to "tap" with a hammer. Where you hear a “dull” sound, you need to pick off the plaster with a spatula and remove it until it stops falling off. Cracks are expanded with a spatula and exfoliated pieces are removed.

Mixer for plaster

A mixer is necessary to obtain a quality solution. The most convenient to use is a specialized mixer, equipped with speed control and inrush current limiting systems to speed up rotation and prevent splashing. The higher the speed, the better and faster the solution is stirred. A mixer with multiple attachments is heavier and more expensive. It requires a spacious container, but such a tool is much easier to work with.

What is a rule and how to choose it?

The rule is a long, even ruler that allows you to detect flaws while checking the plastered surface. Previously, the rule was made of wood. Modern rule — aluminum profile. It is light and durable, almost not subject to deformation. The length of the rule is usually from 1 to 2 meters or more. The most convenient 2-meter rule.

Some modern models equipped with a built-in hydraulic level in the form of liquid ampoules. When choosing such a rule, you need to pay attention to the tightness of the case.

How to choose a grid for plaster?

The mesh is necessary for high-quality fixing of the solution. When choosing a grid, be guided by the size of the cells and the type of grid. For interior work, metal, polyurethane or polypropylene universal meshes with an average cell size of 22 x 35 mm are suitable. For outdoor work, it is better to buy a fiberglass mesh with cells - 5 x 5 mm. This mesh is resistant to temperature extremes and chemical attack.

We make a mixture for plaster

To perform plastering work, a mortar based on cement or gypsum is made, lime mortar and filler. Sand is usually used as a filler. A high-quality mortar should be homogeneous and well balanced, resembling a thick, viscous dough in consistency. Plastering skills are required to work with gypsum-based mortar, as it sets very quickly. Nowadays, ready-made dry mixes with polymer additives are increasingly being used to increase the strength of the plaster.

What is a plasticizer?

To increase the plasticity of the solution, a plasticizer is introduced into it. The solution with it is easier to apply, it turns out more resistant and durable. You can buy a ready-made plasticizer or add CMC wallpaper glue to the solution. This is the cheaper way.

The plasticizer saves Consumables, accelerates the drying of the plaster and prevents the appearance of corrosion in the reinforcement.

What is a plaster beacon?

Plastering on beacons allows you to make a more even surface. Lighthouses are narrow vertical metal protrusions attached to the wall with dowels or plaster mortar. Their installation is a very responsible event and requires scrupulousness and attention. The time spent on the installation of beacons pays off when performing plastering work. The purpose of installing beacons is to create an ideal surface plane. Before the beginning finishing works it is recommended to check the deviations of the walls from a flat plane. After finishing the walls, the beacons are removed.

What tool is needed for wall plastering?

The quality of work depends on the availability of tools and materials. For plaster walls you will need:

• Master OK;
• putty knife;
• rule with level;
• grater and trowel;
• lighthouses;
• net;
• plaster corners;
• steel trowel;
• construction mixer;
• solution;
• solution bucket.

You will also need several pairs of rubberized gloves, as the plaster solution is very caustic. All these materials and tools will help create a completely flat surface.

How to attach the mesh?

Before starting work, the mesh is cut off from the roll according to the size of the surface to be treated. in concrete and brick wall drill holes and install plastic dowels. Grid fastening starts from above, fixing the upper edge with self-tapping screws. Pieces can be put under the hats polyurethane foam. The mesh is fastened in a checkerboard pattern, making the distance between the screws 5 cm. The joints are overlapped. Additional fixation is not needed, as the wall plaster securely fixes the grid.

Plaster thickness measurement

The thickness of a single-layer plaster for walls should be no more than 20 mm based on cement and 15 mm based on gypsum. If you do the work yourself, it is not necessary to measure the thickness. To check the quality of work from hired builders, a special device is used to measure the thickness of the layer: a digital thickness gauge or an electronic meter.

Grout after wall plastering

After applying the finishing layer, the plaster is rubbed with a grater, slightly wetting the wall. Grouting is carried out in 2 stages. In circular motions made counterclockwise, small parts of the wall are gradually processed. At the second stage, the grout is carried out with a felt grater in direct movements to obtain a smooth and beautiful surface.

What should be done after plastering the walls?

Finished surfaces must dry. Wall plaster dries completely within 1 month. All this time it is better not to touch the walls. To speed up drying, open windows and doors to allow air to pass through. After complete drying, the walls must be primed to improve the performance of the wall plaster. If wallpapering is planned, then the walls are simply coated with wallpaper paste.

Do I need to putty plastered walls under the wallpaper?

Puttying plastered surfaces is not necessary if you plan to glue thick wallpaper. The plaster is rubbed with a grater using water, so an absolutely smooth and even surface is obtained. It is enough just to prime the surface and carry out pasting. Acrylic primer strengthens the plaster. But if the work was done poorly or you are going to glue thin wallpapers, putty will not hurt. Before painting the walls, they can simply be puttied without priming.

Look for contacts of construction teams that will perform high-quality wall plastering, as well as store addresses construction stores in the catalog

1. To test the wet and dry strength of old plaster, rub it with a wire brush.

2. To test the hardness of the old coating, run the flat side of the screwdriver across the surface while applying firm pressure to the screwdriver.

3. If the surface remains deep scratches then the old plaster must be removed.

How to determine the presence of voids under the old plaster coating?

4. The entire surface should be carefully checked, especially in places of cracks.

5. Tap the surface with a hammer or a metal rod; in places of voids, the sound will be muffled.

6. In places of voids, beat off the old plaster

How to determine the type of old plaster coating? How to determine what the walls are plastered with?

7. In order to understand whether the old coating is compatible with the new, it is necessary to determine its nature - mineral or polymer.

8. Under the action of the flame: (for example, blowtorch) polymer coatings soften or crack, and polymer binders emit a specific odor.

9. Mineral plasters (lime-cement, cement) do not react to the flame.

How to check the adhesion strength of polymer plaster or paint?

10. If the old coating (plaster or paint) is not to be removed, it is necessary to check the strength of its adhesion to the base.

12. The adhesion strength of paints or polymer plasters with a rough surface can be checked with a spatula or knife.

11. On a 10x10 cm area, apply horizontal and vertical scratches in 2 mm increments. If >80% of the paint is retained, the adhesive strength is considered sufficient.

How to find out the adhesion strength of new plaster with the old coating (paint or plaster)?

When the surface is covered polymer paint or plaster, you need to know what the strength of their adhesion to the new plaster.

13. Lime-cement plaster may not have sufficient adhesion to polymer plaster or paint (saponification).

14. Apply a plaster layer on the surface of the old coating and sink a 50x50 cm grid into it so that the edge of the grid is not covered with mortar. Let dry for 3-4 days.

15. If the solution remains on the surface when the mesh is torn off, the adhesive strength is sufficient. If a fresh mortar or an old coating is removed together with the mesh, then the adhesion is fragile, the old coating must be removed.

How to determine the absorbency of a substrate?

16. This must be done to determine:
. what primer should be used.
. whether it is necessary to use a special solution with increased adhesion.

17. Moisten the base with bottled water.
1) Water is quickly absorbed, the stain increases rapidly. Treat the base with a primer at least 2 times.
2) water is absorbed, the stain slowly increases. Treat the base with a primer.

18.

3) water, slightly absorbed, wets the surface. It is necessary to treat the base with a primer.
4) water flows freely from the surface without wetting it. It is necessary to treat the base with a primer.

Articles similar to How to check the bearing capacity of old plaster?:

Plastering is one of the main stages of repair, and comfort in the house directly depends on them. Therefore, it is necessary to check not only the final result, but also the sequential execution of the technological process.

Before plastering work, it is necessary to carry out a complete cleaning of the room and surface preparation. The walls should be free of dust, dirt and stains of various origins. In addition, it is necessary to comply temperature regime and control room humidity.

The application of the solution should be uniform, and the layer thickness should be up to 50 mm.

Acceptance of works

Acceptance of work performed must begin with an inspection of the corners. This is the most prominent indicator by which you can easily assess the quality of plastering work. The resulting surfaces should be perfectly even and smooth, with clear edges. All cracks, bumps, potholes and gaps are the main sign of poor-quality plaster work.

To check the strength of the connection of the plaster with the surface, apply several blows with the palm of the hand to the sides of the corners and in arbitrary places. No delaminations and booming sounds from voids are allowed.

In addition to a visual check, it is necessary to take a ruler-rule, 2.5 meters in size and attach it to the plastered surface. If for such a length the gap to the surface does not exceed 5 mm, then the result is excellent. To check the verticality of the walls, a level or plumb line is required. The quality criterion is the same - a gap of no more than 5 mm per 2.5 meters of length.