Preparation of stone and concrete surfaces for plastering. Surface preparation for plaster. Preparation of wooden walls for plaster

The base for plaster must adhere firmly to the plaster mortar. Surfaces intended for oshtu; curing, incised, cleaned, moistened with water, if necessary, cut off the influxes on the surface, choose the seams. In all cases, contaminants are removed from the surfaces, especially May, tar.

Rubble stone walls are prepared as follows; Masonry seams, if they are flush filled with mortar, are chosen to a depth of at least 15 mm, and the surfaces are cleaned with steel brushes. When laying, it is better not to fill the seams to this depth, insert pieces of wire into them at intervals of 10-15 cm or wooden corks and hammer nails into them. A wire plexus is made along the wire and nails, on which the plaster cast is well held. New brick walls, folded empty, are swept with a broom or broom. If the joints are filled with mortar, they are selected to a depth of at least 15 mm.

Old brick walls are prepared in the following sequence: seams are selected, the surface is cleaned with steel brushes or sandblasting, or notched. Slag concrete surfaces, new and old, are also notched. For better adhesion to the plaster layer, holes are drilled in the cinder-concrete surface, plugs are installed in them, and a wire plexus is arranged along the nails driven into the plugs.

When preparing surfaces, they are cleaned with steel brushes, as well as trowels, on which brushes are attached instead of a trowel disc. Surfaces are incised manually with an ax, bush hammer, cog, chisel, applying strokes on the surface - strips or pits with a depth of 3 to 5 mm. Bucharda has 16-26 pyramidal teeth on the ends or cutting in the form of straight blades. The chisel has a smooth long blade. Gear, trojanka, scarpel, tongue and groove - varieties of chisels with teeth on the blade. Tongue - a round rod, the end of which is processed into four faces, like a nail. It is convenient for them to choose seams or chip off pieces of hardened mortar when processing plaster.

When preparing surfaces, safety regulations must be observed. All tools must be firmly attached

on durable, burr-free handles. Work should be carried out in gloves and goggles. The power tool must be checked for conductance.

Cornices, corbels, columns, pilasters are often framed with a mesh, and then plastered with any solutions for different textures, but without processing the applied plaster with percussion instruments. Set it up like this. First of all, a supporting frame is placed, a distribution frame is welded to it or tied with wire, along which the mesh is stretched, often attaching it. It is necessary to stretch the mesh as tight as possible, since a loosely stretched mesh vibrates, and the solution applied to it will fall off. Before plastering with lime-gypsum mortars, the mesh is painted over with oil paints or cement milk. This protects it from rust and destruction.

To create roughness, shingles are stuffed onto wooden surfaces (Fig. 5.1). So that the surfaces do not warp, the boards are split and wedges are driven into the splits. To reduce the sound and heat conductivity of wooden surfaces, they are covered with matting and felt before stuffing. Before stuffing, the shredding is sorted into pro-style (at least 3 mm thick), narrow and outgoing, more even and thicker (not more than 5 mm thick); blade width from 15 to 20 mm; wider shreds warp.

Rice. 5.1. Wrapping and tools used:
a - plaster knife; b - plaster hammer; in - the location of the potato pancakes; g - stuffing of wounds; 1, 2 - nails

First of all, a prostrate shred is lightly nailed to the surface. Having stuffed it with a whole row along the length of the wall, they begin to stuff the output shred. Both shreds are nailed at an angle of 45 ° to the floor so that cells are formed. A distance of 45 mm is left between the pancakes of the prostyle and the output row, thereby forming cells or cells 45 x 45 mm in the light. The output shingle is nailed with plaster nails through two prostrate pannels into the third. In the course of work, the nails slightly driven into the prostile shred are taken out and used. Dranitsy join the ends, and do not impose one on the other. The ends of the fray must be nailed. Stuffing piece shredding is a labor-intensive operation. It is better to use shingle boards, which are assembled and fastened with nails on a workbench for laying shreds.

Sometimes, instead of shredding, a mesh is stuffed, the cells of which should not be larger than 40 x 40 mm. The mesh is fixed with nails every 10 cm, bending them. The joints of dissimilar surfaces are tightened with a metal mesh so that cracks do not appear on the plaster. Cracks form because the plaster mortar dries out at different times on dissimilar surfaces. To avoid this, the joints are tightened with a mesh with 10 x 10 mm cells, cut into strips 10 cm wide and nailed along the edges after 10 cm. If there is no mesh, wire weaving can be used. To do this, nails are hammered through 40-50 mm and they are braided with wire. Metal beams located between reinforced concrete slabs are also tightened with a mesh. To do this, reinforcement is welded to the beams in the form of a large mesh or in the form of individual rods for attaching mesh strips to them. The edges of the mesh should overlap the seams between the slabs and the beam by at least 5 cm. The mesh should be cut and stretched with gloves on.

In order for the plaster to be strictly vertical and horizontal, the surfaces are hung and leveled according to marks and beacons before plastering (Fig. 5.2, 5.3). Beacons are made of gypsum or the same mortar used for plastering, or wooden or inventory metal beacons are used. For hanging surfaces, a plumb line, a level with a rule, a water level are used. It is most convenient to hang the walls with a plumb line.

The hanging procedure is as follows (see Fig. 5.2). In the corner of the wall at a distance of 300-400 mm from the ceiling, a nail is driven in to the thickness of the plaster. A plumb line is lowered from the head of this nail to the floor and nail 2 is driven in below so that its head almost touches the cord. On walls above 3 m, an intermediate nail 3 is driven in. The opposite corner of the wall is also hung, driving in nails 4, 5 and 6.

Rice. 5.2. Hanging the walls with a plumb line:
a - plumb; b - hanging scheme; 1-12 - nails; 13 - stamps; 14 - rule; 15 - lighthouse

After that, the cord is pulled over the heads of nails 1 and 3, then 2 and 4. If the surface of the wall is even, then the hammered nails are left in it. If the cord touches the surface, it is cut down in this place. When this is not possible, then in one row the nails are pulled out to such an extent that plaster of the desired thickness is obtained in a convex place. Then the cord is pulled over the heads of nails 1 and 4, 3 and 5, 2 and 6, driving intermediate nails 7, 8, 9, 10, 11 and 12 along the tensioned cords, along which beacons will be arranged. The distance between the beacons can be from 1 to 3 m.

Having hung all the walls, they proceed to the device of stamps and lighthouses. Gypsum dough or mortar is smeared on each driven nail, its front side is leveled at the level of the nail head and cut off from the sides. Stamps are made in order to establish a rule on them, which is fixed with plaster, nails or clamps. Under the rule, gypsum or mortar is applied. After the gypsum or mortar has set, the rule is removed by striking it with a hammer. A strip of mortar, called a beacon, remains on the wall. There are defects on it, they are corrected and rubbed with a half-cloth. To hang the rule with a level, nails are driven into the ceiling in rows to the thickness of the plaster. Then they take any nail for the main one, attach one end of the rule to it, and the other end to one of the hammered nails. When pulling out or driving in a nail, the rule is set exactly according to the level. Thus, from each precisely installed nail, further installation of hammered nails is carried out, on which stamps and beacons are then smeared.

Rice. 5.3. Hanging the ceiling with a water level:
a - level detail; b - hanging; 1 - rubber tube;
2 - glass tube with divisions; 3 - nail
On fig. 5.3 shows hanging the ceiling with a water level. If the water is on the same scale at both ends of the level, then the surface of the ceiling is horizontal.

One of the important stages of building a house is finishing the facade. Various methods are used for this. The most common option is plastering, which is suitable for any surface, be it wood, brick, concrete or other material. Thanks to the external plastering of the walls, it is provided:

• protection from the negative impact of the external environment;
• thermal insulation;
• moisture protection;
• air exchange;
• aesthetics.

Plastering the facade is not a very complicated process, the main thing is to follow all the technological rules. An important step in this case is the preparation of the surface for plastering, how well it is done depends on the final result.

For new buildings, the preparation of brick surfaces for plastering consists of cleaning from dust, dirt and other stains from it. If possible, remove the bumps and influxes on the wall. If we are talking about, which was previously plastered, then it is necessary to remove the old damaged finish.

You can detect such areas with a hammer or a wooden block, which is used to tap the wall. In places where a dull sound is heard, the old plaster is removed. Do this with a chisel and hammer or perforator.

The next stage in the preparation of the brick surface is the jointing. This stage is skipped if the bricklaying was done in a wasteland or if we are talking about repairing the finish. Next, the walls are primed, which involves treating the walls with a special composition that ensures good adhesion of the plaster.

An important stage in the preparation for plastering is the reinforcement of the walls. Do this with a chain-link mesh. According to accepted building codes, the installation of a reinforcing mesh is mandatory if the thickness of the plaque is more than three centimeters.

But experts recommend doing it anyway. The mesh, providing good adhesion between the brick wall and the plaster, eliminates the appearance of cracks on the facade. Strengthening is mandatory when preparing the surface of the basement part of the facade, since, as a rule, it is made of concrete.

On this, the preparation of the surface to be plastered can be considered complete. But before applying the plaster, vertical beacons are installed from the guide profiles, along which the surface is leveled during the application of the plaster layer. Lighthouses can be steel or plastic.

In order to avoid cracks in the plaster, internal and external corners are also installed on window and door openings. Plastering is carried out after the primer has completely dried. Do this only in dry weather, as rain can completely wash off damp plaster.

Surface preparation for plastering walls made of foam blocks, reinforced concrete slabs and other materials

Surfaces for plastering, made of foam blocks and reinforced concrete slabs, include the same steps as in the preparation of the brickwork facade, only the stage of jointing is excluded, since when using these materials, there are fewer joints, respectively, and places of hooking.

Jointing is not required for a facade erected from (SIP-panels) using Canadian technology. A primer is immediately applied to them, which gives smooth surfaces a slight roughness (for good adhesion to the plaster mixture). After it dries, a plaster mesh is stuffed. To apply the finish layer, various tools or special equipment are used.

Surface preparation for plastering a wooden house

Work on plastering the facade of wooden structures is carried out only after complete shrinkage of the structure. And this period is from one to two years. The preparation of wooden surfaces includes a sufficient amount of work, which includes:

1. Wall alignment. The elimination of irregularities is carried out by squeezing or stuffing the tree.
2. Processing smooth areas to give them a slight roughness.
3. Sealing gaps between timber or boards.
4. Cleaning the surface of the facade from various contaminants.
5. Treatment with an antiseptic to protect the tree from the negative effects of biological factors.
6. Facade reinforcement. This procedure is done by upholstering the facade with shingles or chain-link mesh. When using shingles, lay it in two perpendicular rows, thus forming square cells. Attach shingles to wooden walls with nails.

On a wooden surface directly plastering is carried out in several layers. The first of these is a rough, liquid layer. Its thickness should not be 0.5 cm. The second - a primer layer, is applied after the previous layer has completely set, after about 1-2 days, depending on the air temperature. The thickness of the second layer should be about 2 cm. The finishing (coating) with a thickness of 50 mm is applied a few days (2–7) after the plastered surface has completely dried.

When performing work, it is important to pay attention to the thickness of the plaster. The finish should not be very thin, otherwise gaps or cracks may form on the surface. The texture of the plastered facade can be smooth, striated or solid rough.

What types of plaster are used?

Manufacturers of building materials offer a large selection of mixtures for plastering the facade. They differ in composition, characteristics, texture and other indicators. The texture of the material depends on the grain size of the components that make up the mixture. The components of the mixture include quartz sand, marble chips, glass dust, dye granules, wood fibers, etc.

Depending on the composition, the following types of mixtures for plastering the facade are distinguished:

1. mineral mix. This is the most common and cheapest type of plaster, more often used for brick and concrete surfaces. However, in terms of stability, mineral plaster is inferior to other types, in addition, it has a very narrow range of colors. To obtain the desired shade, the surface has to be additionally painted.
2. silicate mixture. Differs in the presence of liquid glass in the composition. The cost of the material is relatively high, but the durability justifies the price. Suitable for masonry surfaces and with insulation.

acrylic blend. It is elastic, the material dries quickly, so you need to perform plastering work very quickly. Possesses vapor permeability and moisture resistance. Easily washes off any dirt. Suitable for walls made of any material, including those with insulation.

Manufacturers also offer silicone plaster. This is the most expensive mixture, suitable for any surface. It has elasticity and dries very quickly. It differs in durability, the only drawback is low vapor permeability. The choice of material for plastering the facade depends on the purpose of the structure, size and many other factors.

Plastering is one of the most commonly used ways to level walls and prepare them for further decorative finishing.

Ready-made plaster mixes are affordable, easy to use and suitable for finishing any surface - brick, concrete, wood and even metal.

True, pre-plastered surfaces must be prepared accordingly. The preparation of walls for plastering depends on the technical characteristics of the material from which they are made.

The need for preliminary preparation

The better the adhesion at the base, the stronger the plaster layer will be.

Surface preparation for plastering is a mandatory procedure, regardless of what type of plaster mixture is used.

The goal of plastering is to maximize their service life. First of all, for this it is necessary to improve the adhesion between the plaster mortar and the treated plane.

Adhesion is a physical term that refers to the degree of mutual penetration of different materials into each other. In the construction and finishing business, adhesion characterizes the ability of different compositions: adhesive, paint and varnish, putty and plaster to create a strong connection with the treated surfaces.

In the arsenal of modern finishers there are various ways to increase adhesion, which can be used both individually and in combination. The use of this or that technology is dictated by the properties of the processed material: its porosity, smoothness and surface strength.

Preparing walls for plaster is technically not a complex production process that any apartment owner can do with his own hands. But at the same time, it should be produced with the highest quality and in compliance with all building standards.

From this insignificant, at first glance, the procedure will largely depend on the durability of the entire decorative wall cladding. It will allow you to avoid such unpleasant consequences as swelling and peeling of the plaster from the supporting base, cracking of the wall surface, the appearance of foci of fungal infections in the resulting voids, etc.

General training

There are several rules for preparing the surface for which do not depend on the characteristics of the wall material. Usually, this process is carried out already at the stage of building construction: the fewer defects the walls have, the less time, effort and money it will take to plaster them.

Wall construction stage

Build walls strictly in accordance with regulations

Walls "littered" in the horizontal and vertical plane will require considerable effort to level them.

According to building regulations SNiP, the deviation of the plane of walls intended for treatment with plaster mortars should not be more than:

• 3 mm per 1 m of height or length when processed with basic plaster compositions;
• 2 mm per 1 m of the wall when plastering with finishing compounds;
• 1 mm per 1 m when using decorative plaster.

These standards depend on the maximum thickness of the applied mortar layer. If the base cement mortar can be applied with a layer of up to 12 - 15 mm, then finely dispersed decorative plaster is intended for application with a layer of no more than 2 mm, and it will simply be impossible to even out the defects of the supporting base with it.

Surface cleaning

The grinder will help smooth out the bumps

Also, regardless of the material of manufacture, the preparation of walls for plastering includes cleaning them from any contaminants. Bases lined with stone, cinder blocks can be cleaned with a weak 3% hydrochloric acid solution, or with household chemicals.

After that, their surface must be washed with clean water and dried. You can try to get rid of oily stains either with organic solvents (acetone, gasoline, white spirit), or use folk remedies. Oily clay is taken and applied to the soiled surface in a thick layer. After drying, the clay is removed along with the fat absorbed into it. If necessary, clay can be applied to the affected area a second time.

Places of growth of the fungus are cleaned and treated with antiseptics

Usually, between the construction of a house and its interior decoration, there is a significant time required for the process of shrinkage of the base to end. This period takes about a year, and during this time the walls can become saturated with dampness, become covered with fungus and mold, therefore, when preparing surfaces for plastering, you should carefully examine them for damage, and also dry them thoroughly.

In hot, dry times, this can be done by opening windows and doors wide open for several days. In cold or rainy weather, you can dry the supporting base with a heat gun or building hair dryer.

Places affected by the fungus will need to be treated with a special antiseptic primer or bleach. If this is not done, the fungus will continue to multiply in the thickness of the plaster, gradually destroying the finish.

If it is planned to plaster old walls, then in this case it is necessary to thoroughly clean the entire surface from the previous finishing material, up to the exposure of the supporting base. Applying a new layer of mortar on top of the old one will be absolutely impractical, since the plaster that has served its purpose will be a very unreliable base.

Even if, at first glance, it adheres quite firmly to the surface of the wall, during operation, cracks and delaminations inevitably appear in its depth, significantly worsening the technical properties, therefore, preparing the old wall for plastering necessarily involves the complete removal of the old finish.

However, as experienced finishers assure, in some cases it is possible to deviate from the rules and apply a new mortar over the old one, but this requires good reasons - either such a repair is considered as a temporary measure “until better times”, or there is 100% confidence in the strength of the old plaster, or there is no time and opportunity for the complete dismantling of the old cladding.

Preparation of various surfaces

House owners who decide to do the interior decoration work with their own hands often have the question: “how to prepare a wall for plastering if it is made of brick (concrete, wood, aerated concrete)?”, Therefore, you should consider in more detail the features of preparing various building materials for plastering . For more information on wall preparation, see this video:

Preparation of wooden surfaces

To strengthen the adhesion of the mortar with a wooden base, a shingle is used

The preparation of wooden surfaces consists in maximizing the adhesion with the plaster mortar. The fact is that the coupling between wood and cement or gypsum mortars is very poor.

This is due to the high porosity and weakness of the top layer of wood, as a result of which the plaster composition simply cannot firmly fix on it. To create a strong coupling, the walls prepared for processing should be additionally covered with an adhesion-enhancing material. In relation to wooden surfaces, this can be:

1. Wooden slats ("shingles").
2. Reed mats.

Plaster mesh has different cell diameters and can be made from various materials - steel, fiberglass, plastic, etc. It is fixed on the wall with nails or screws. A flat mesh with a small mesh size is used when treating walls with a thin layer of mortar.

If it is required to apply a significant layer of plaster, then it is better to use a three-dimensional chain-link mesh with a large mesh.

Shingles and reed mats are attached to the wall surface with nails. Shingles are fairly thin slats that are stuffed diagonally crosswise onto the wall. Mats are simply nailed to a wooden plane, and the edges of the nails are bent for better fixation.

Since shingles are thin slats up to 15 - 25 mm wide, when nailed, it can prick and break. To avoid this, pre-moisten the slats in water.

Brick wall preparation

A brick wall can also be laid with a construction mesh

The brick itself forms a fairly good coupling with any plaster solutions, both cement-based and gypsum-based. However, the brick surface also needs additional processing to increase adhesion.

First of all, the wall should be cleaned of dirt and weakly adhering fragments. Particular attention should be paid to the seams, where dust and construction debris usually collect. To clean the brick, you can use a metal brush or grinder. In a circular motion, you should walk over the entire surface of the wall, and clean the seams separately. After that, the brick surface is cleaned of dust with a vacuum cleaner or a wet sponge. For more information on wall preparation, see this video:

If the wall has too large defects, a thick layer of mortar will be required. In this case, for the best effect, problem areas should also be covered with a plaster mesh, which will allow you to apply the solution in a layer of up to several centimeters without the threat of its peeling.

The metal mesh is attached to the brick by means of dowel-nails or special dowel-fungi with wide plastic caps.

Fiberglass or polymer options can also be glued using PVA glue or adhesives already applied to their back side (self-adhesive meshes).

Monolithic concrete walls

Notches or plaster mesh will improve the adhesion of plaster to a smooth monolithic wall.

The preparation of concrete surfaces also has a number of its own characteristics. It often happens that the walls in monolithic houses have a very smooth, almost glossy surface. This is due to the use of modern technologies for pouring concrete, when not boards or plywood are used as formwork, as before, but collapsible structures made of metal or laminated panels.

Being very smooth, such a surface, when compacting concrete, makes it perfectly even. It seems that this is a definite plus, but not from the point of view of finishing specialists. The glossy surface of concrete walls has a very low porosity and, as a result, a low adhesion index. For more information about monolithic concrete, see this video:

In order for the plaster mortar to be firmly attached to monolithic concrete, several different technologies are used.

1. Application of notches to the concrete surface. To do this, you can use various "percussion tools": a hammer with a chisel, an old hatchet, a mason's pick, etc. In addition, for applying notches, you can use a puncher with a spatula nozzle or a grinder with a diamond wheel.
2. Processing with a grinder. At the same time, an abrasive wheel or a wheel with a metal brush is installed on the grinder. Processing of a concrete wall is carried out by rotational movements over its entire surface. The applied scratches and grooves make the concrete surface rough, increasing the level of adhesion many times over.
3. Covering with plaster mesh. Concrete can be pasted over with fiberglass or plastic mesh, or fitted with a metal mesh-netting, which is fixed to the wall with dowels. Also, the steel mesh can be fixed on the ledges of the reinforcing cage by spot welding. For more information on preparing the base for finishing, see this video:

As can be seen from the description, any owner of an apartment can prepare any bearing surface for plastering with his own hands. To do this, you just need to have the initial skills of owning finishing tools and apply sufficient diligence. The main thing to remember is that the durability of the entire decorative finish depends on the quality of the preparation of the wall for applying the plaster.

This article will discuss how the preparation of various surfaces for plastering. To begin with, we highlight the main surfaces that are very common in the practice of construction repair work.

List of surfaces to prepare for plastering:

1. Preparation of wooden surfaces.
2. Preparation of brick surfaces.
3. Preparation of stone-like surfaces.
4. Preparation of concrete surfaces.
5. Preparation of the metal surface.

Preparation of wooden surfaces

This preparation requires additional materials, and this method is a bit outdated. But sometimes it can still be found on construction sites.

• Stuffing plaster on the surface;
• Fastening a metal mesh to a plastered surface.

Stuffing of plaster shavings is done as follows. Thin wooden boards are taken and stuffed onto the surface in two layers. The first layer of shavings consists of curved wooden boards, you can actually use different ones, but not less than 3mm thick and not more than 5mm thick. The second layer of shingles should be stuffed at an angle, and already consist of even boards, the thickness of such boards should be the same as that of the boards of the first layer, a deviation in thickness of ± 2 mm is possible.

The fastening of the metal mesh to the wooden surface occurs with the help of nails. The fixed metal mesh should have cells with a size of 10 * 10mm. But at the same time, one more point must be taken into account. When attaching a metal mesh, the thickness of the plaster should be no more than 40mm.

If the thickness of the plaster needs to be increased, then the roughness needs to be supplemented. This is done with the help of nails that are driven 100mm apart and 20mm deep. After that, a wire is wound around the nails, due to this a kind of mesh is obtained.

Preparation of brick surfaces

This type of surface is not so difficult and tiring to prepare compared to wood. If the wall has just been laid out, and has a laid out wasteland, then all that remains is to clean it of dust and make notches if necessary.

In the case when the seams between the bricks are completely filled with mortar, the mortar in the seams must be cut down to a depth of at least 1 cm. After cutting down, first clean with a metal brush, and then you can clean it from dust, if necessary, make notches. This completes the process of preparing brick surfaces.

Preparation of stone-like surfaces

Stone-like surfaces generally have sufficient roughness. They are prepared quite simply - dust and pollution are cleaned with simple brushes, metal brushes, if necessary, if there is not sufficient roughness, notches must be made.

Preparation of concrete surfaces

Concrete surfaces that have only recently been made and delivered must be carefully cleaned of dust and dirt. It is necessary to make notches with a hammer and a chisel (troyanka). After the notches are ready, it is necessary to re-clean from dust and dirt and proceed to the plastering work.

In the case when the walls have an old finish or have been in a very long operation, it is necessary to clean them more thoroughly. If the wall was finished in the form of painting, before plastering, the old painting must be removed.

K category: Plaster work

Preparation of surfaces for plastering

Preparation for plastering stone, brick and concrete surfaces. The strength and durability of the plaster largely depend on the cleanliness and roughness of the bases, which ensure good adhesion of the plaster mortar to the surface to be finished. Insufficiently clean and rough bases are prepared in various ways.

Dirt from the surface is scraped off with a steel brush or spatula.

Stone, brick and concrete surfaces:
- for cleaning from soot, they are washed with a 3% solution of hydrochloric acid, followed by washing with clean water;
- stains of non-drying oils are coated with greasy clay with a layer 0.5-1 cm thick. After complete drying, the clay is removed and the surface is washed with clean water;
- salt efflorescence is removed with a steel brush, after which the surface is washed with a 0.5% hydrochloric acid solution, and then with clean water.

To remove old paint and roughen stone and concrete surfaces, as well as brick surfaces previously plastered or laid without waste, they are cut manually with a double-sided pointed hammer or an IP4112 pneumatic chipping hammer. At the same time, the number of notches per 1 m2 of the surface should not be less than 300.

The same tools cut down the influx of mortar on brick or masonry and concrete.

To roughen concrete surfaces, they are sometimes treated with a 15% hydrochloric acid solution, followed by rinsing with clean water.

With large volumes of work, roughening surfaces made of old brick, smooth concrete and painted with water-based paint compositions is achieved by sandblasting.

Tools and machines for preparing stone, brick and concrete surfaces for plastering are shown in Figure 65.

The preparation of stone, brick and concrete surfaces is carried out by a link of two plasterers. When processing surfaces in rooms with a height of up to 3 m, inventory tables are used with or without flip-over boards, and at a room height of more than 3 m - towers.

When working with a mechanized tool, workers must ensure that the tips (scarpels, trojans, bush hammers) are well fixed in the tool body, the compressed air hoses have reliable butt joints and are firmly attached to the hammer and compressor nozzles. It is allowed to work in tightly buttoned overalls, gloves and goggles.

When working with hydrochloric acid solutions, workers must be provided with on-duty protective equipment for the duration of work: acid-resistant suits, rubber aprons, gloves and half boots, as well as goggles.

An exercise. Determine how many notches need to be made on the side planes of the brick when laying it with a poke or spoon, if at least 300 notches per 1 m2 must be applied to give the surface sufficient roughness.

Rice. 1. Tools and machines for preparing surfaces for plastering: a - double-sided hammer with double sharpening; b - bush hammer; c - plaster hammer; g - plaster knife; d - nippers (nippers); e - compressor unit; g - trojans; h - scarpel.

Reinforcement of plaster and arrangement of bases reinforced with mesh. For the reinforcement of plaster and the installation of mesh reinforced bases, woven wire mesh 1 m wide with square cells measuring 10X10 mm is used. Wire diameter 0.7-3 mm. The mesh is tied to the frame with a copper-plated or galvanized knitting soft wire with a diameter of 0.8 mm. The panels are overlapped in length and width with an overlap of 50 mm and firmly fastened together with knitting wire. The mesh is cut into panels of the required length and width with manual scissors for cutting metal.

Rice. 66. Wire weaving mesh on nails: a - single; b- double.

Furrows with hidden pipelines in brickwork are tightened with a mesh, tying it to metal steel staples with a diameter of 6-8 mm, driven into the seams of the masonry 20-30 cm across the furrow, or fixing the mesh with nails 80-100 mm long, hammered into the seams of the brickwork through 20-30 cm on both sides of the furrow.

Before laying in place, metal beams, including girders and stringers, are wrapped with mesh with binding over the mesh with knitting wire in a spiral with a step of not more than 15 cm. In the absence of a mesh, beams and stringers are tied with a knitting wire in a spiral with a step of not more than 5 cm.

To form a gap between the shelf of the beam to be plastered and the mesh, 2-3 steel bars with a diameter of 6-8 mm are welded or tied to the shelf.

Door and window slopes, as well as individual places with a plaque thickness of more than 20 mm, are reinforced with a mesh with fastening it with nails or gypsum mortar moldings before plastering. In the absence of a mesh, weaving is made from wire with a diameter of 0.8-1 mm along incompletely hammered nails 80-100 mm long.

The joints of wooden structures with stone, brick, concrete and gypsum concrete are reinforced with mesh strips 15-20 cm wide, fixed to wood, brickwork and gypsum concrete after 15-20 cm with nails, and to stone and concrete - by freezing with a solution.

Rice. 2. Reinforcement of plaster at the junction of wood and brick.

Reinforced mesh bases for plaster are made when performing lightweight structures of partitions, suspended ceilings, decorative columns, pilasters, corbels and cornices, made for architectural reasons and in order to save materials, as well as, if necessary, isolate the plaster from damp walls, basement walls, etc. When making lightweight partitions, the mesh is nailed with wire staples or nails every 15 cm to wooden bars 25-50 mm thick and wide, reinforced in advance after 30-40 cm.

Rice. 3. Reinforced mesh structures: a - a partition with a mesh along wooden bars (1 - vertical bar, 2 - horizontal bar, 3 - mesh); b - suspended ceiling with mesh fastening to rods (1 - hooks, 2 - rods, 3 - mesh); in - columns and columns with fastening of the grid to the frame (U - vertical rods, 2 - grid).

On brick and concrete walls and floors, the mesh is tied to steel rods with a diameter of 6-8 mm, welded to pre-installed pins, hooks, pendants made of round or strip steel. The rods are welded to form a cell of 40X40 cm. To ensure a plaster layer of the minimum allowable thickness on walls and ceilings (at least 20 mm for high-quality finishes), the rods are installed on wooden or mortar beacons pre-made every 0.8-1 m.

On pillars, columns and pilasters, the mesh is tied to a frame formed from vertical metal rods fixed to wooden planks or circles (with round columns) with nails or to steel horizontal belts with a diameter of 6-8 mm by welding. The metal frame should form cells measuring 40X40 cm.

The metal mesh is tied to metal frames at each intersection of the rods with a knitting wire, using wire cutters when tightening the knots. The best way to attach the mesh to the frame should be considered to be tying it with a spiral seam, using the ends of a wire up to 2 m long, with which the mesh is sewn to the frame rods.

The first layer of plaster over the grid is applied from a thick cement mortar (consistency 3-4 cm according to a standard cone) by coating with reinforcement of the solution with wool or chopped organic fiber.

In the case when it is planned to plaster over the grid with lime-gypsum mortar, the grid is pre-painted with oil paint, bituminous varnish, or the grid is coated with cement mortar, and subsequent plastering is done with lime-gypsum.

- Preparation of surfaces for plastering