37764 0

Facade finishing is one of the most important building operations. Exterior wall coverings are exposed to atmospheric precipitation, cyclical freezing / thawing and exposure to harsh ultraviolet rays. Such difficult operating conditions put forward increased demands on the quality of the finish. It is very expensive and time-consuming to eliminate faulty façade walls. We'll have to mount scaffolding, wait for good weather, remove construction waste. To exclude the occurrence of unpleasant situations, you need to take all measures to prevent them.

Facade walls are decorated with various materials and technologies. Reinforcing stack is used in two cases.

To improve the performance of the plaster layer. For such purposes, it is better to use a galvanized wire mesh.

Full metal mesh

The fact is that among the many advantages of foam blocks, you must definitely pay attention to one very significant drawback - low physical strength. Another problem is that concrete blocks begin to crumble during freezing / thawing in conditions of high specific humidity. As a result, cement plaster begins to flake off with all the negative consequences.

Reinforcing mesh allows the plaster to adhere to the wall surface. Conversations that such a mesh should be used with a large thickness of plaster, which due to this, does not appear on the plaster of cracks, have only partial confirmation. Firstly, there are simpler and cheaper methods for avoiding cracks in thick plaster. The easiest way is to cover the solution in a thin layer in several steps. Secondly, it is possible to increase the adhesion of the solution to the facade wall due to a slight increase in the amount of cement in the solution. If this is not enough, then spray with cement milk is done.

To protect front wall insulation from damage. Reinforcing facade mesh is used during the finishing of foam insulation boards.

Not to improve the adhesion of glue to the surface of expanded polystyrene and to prevent cracks, as some "sofa" builders write, but specifically for mechanical protection.

Why do we say so? The surface of expanded polystyrene is protected from the negative effects of ultraviolet rays and, oddly enough, damage from birds. For some unknown reason, birds are very fond of pecking foam, if you leave it unprotected, then soon many large and small depressions will appear on the surface. Conclusion - polystyrene foam needs to be closed. The cheapest and most reliable method is to use glue.

By the way, the advertising characteristics of manufacturers of plastic reinforcing nets “they are not afraid of UV” do not in any way affect their actual performance. The fact is that even the thinnest layer of glue or other cement-sand mixture does not completely transmit ultraviolet rays. Why should a consumer pay for properties that he doesn't need? And one more nuance. Most often, builders fix the reinforcing mesh on the entire wall. We think that this is done either out of ignorance of physical properties, or by a desire to earn more. We advise you to use a reinforcing mesh at a height of 1.5–2.0 meters, there is no need above. No one will damage the finishing screed so high on the foam. Mechanical damage occurs due to various shocks, careless chores near the front wall, etc.

Types of facade reinforcing meshes

Facade reinforcing nets are made of galvanized wire or polymers. The former are used for facade plastering, and the latter are for universal use.

Modern facade mesh

Prices for construction reinforcing mesh

Construction reinforcement mesh

Metal mesh fixation technology

Metal meshes are used only for cement-sand facade plasters, foam insulation is not finished with them. The reason is the small thickness of the screed on the foam plates. And the metal mesh cannot be aligned with such precision; it must be pressed with a thick layer of mortar. The metal facade reinforcing mesh is able to withstand great efforts, it is used if it is necessary to apply a thick layer of plaster on an uneven base.

The algorithm for fixing it has several features, the implementation of which guarantees the expected effect. The mesh can be laid in both vertical and horizontal stripes. For the strength of the plaster, this does not matter, decide for yourself how it is more convenient for you to work. How to properly fix the metal mesh to the facade wall?

Step 1... Take the dimensions of the wall, cut the metal mesh along them. Select the cutting tool according to the wire diameter. Universal tool - metal scissors.

If they are not there, then a thin mesh with a wire diameter of up to 0.8 mm can be cut with ordinary scissors. True, after that, these scissors will have to be sharpened, they will no longer cut the paper.

Prices for construction scissors for metal

Step 2. The metal mesh can be fixed with dowels, the length of the hardware must provide a strong fixation. For facade walls made of foam blocks, ordinary nails 80–90 mm long can be used. They are easily driven into blocks with an ordinary hammer, working with them is much faster and easier. Nails are much cheaper than dowels, and the quality of fixation is no different. Use dowels only on brick or concrete facade walls.

Step 3. Using an electric drill with a hammer drill, drill the first hole for the mesh. The depth of the holes should be several centimeters deeper than the length of the plastic part. Otherwise, it is impossible to insert the dowel to the required depth - the hole is slightly filled with brick chips during drilling and reduces its effective depth. It is difficult to remove it from there, it is better to drill more.

Important. The height of the protruding part of the dowels should not exceed the thickness of the plaster mortar. Keep track of this parameter throughout the entire area of \u200b\u200bthe facade wall so that you do not have to adjust the dowels during plastering.

Step 4. Drill the holes in one line at a distance of about fifty centimeters, hang a mesh on each dowel. Pull it a little, do not allow large irregularities. The position of the line does not matter, it can be vertical or horizontal, depending on the method of attaching the reinforcing metal mesh.

Step 5. Check the position of the opposite edge of the grid, if it lies unevenly, then move the grid to adjacent cells.

Fastening the plaster mesh - diagram

Step 6. Everything is normal - continue to fix the mesh, install the dowels in a checkerboard pattern. Most metal meshes are one meter wide, so you need three rows of hardware to fix it.

Important. In places where two rolls overlap, install the dowels at a distance of approximately 10 cm from the edge. On these dowels, two strips of reinforcing mesh will be hung simultaneously.

Step 7. In places of window and door openings, the mesh is cut to size. But it's okay if you don't cut it off, but just bend it. Just make sure that the edges of the folded sections do not protrude beyond the thickness of the plaster layer.

During the plastering of such a facade wall, the solution must be thrown in several stages. For the first time, the mass should be slightly thicker than for the final leveling. Specific values \u200b\u200bdepend on several indicators and are determined individually, taking into account the practical experience of the master. The consistency of the mortar is influenced by the weather, the ability of the facade walls to absorb moisture, the linearity of the wall, the maximum parameters of irregularities, etc.

Step-by-step instructions for fixing plastic nets

The durability of its operation largely depends on the correct implementation of the recommendations for the installation of a plastic reinforcing mesh on a foam insulation. In all cases, do not rush, work carefully. We have already mentioned that there is no need to reinforce the entire wall in height, it is enough to protect only the lower vulnerable area. But these are our recommendations, if in doubt - protect the entire surface of the facade wall.

Any brand of glue is suitable for gluing the mesh. Read the instructions, it must have high adhesion to plastic materials. In most cases, a finishing layer of glue with a thickness of several millimeters is applied over the plastic reinforcing mesh. The topcoat is done with facade paints or a thin layer of decorative plaster.

Step 1. Examine the surface of the slabs. If they were fixed with dowels, then completely sink the caps and seal the grooves. You can close the slots at the same time, but this is not necessary. The fact is that the slots will automatically close during the application of the first layer.

Step 2. On the wall, draw a horizontal line along the height of the reinforcement layer. It will help you keep track of the height of the adhesive. A thin layer of material dries quickly, and this not only causes an increase in material consumption, but also negatively affects the final leveling of the layer for painting.

Step 3. Prepare the adhesive according to the manufacturer's instructions. Always pour water into the container first, and then add the dry mixture. This technology will greatly simplify the mixing process. You can mix it manually with a trowel or using a mixer attachment to an electric drill.

The second method is not only easier, but also more effective. Stir for a few minutes, and then leave the mixture to stand for another 5-6 minutes. During this time, moisture will be evenly distributed throughout the volume, the smallest dry lumps of glue will completely disappear.

Step 4. The glue is applied to the wall with a spatula; the longer it is, the smoother the surface is. Professionals work with spatulas up to 70 cm in size, beginners can use shorter ones at first.

Practical advice. If you are just learning to apply glue to the surface, then it is better to immediately get used to working with both hands. One gets tired - connect the second hand. Believe me, it's not that difficult, you just need to show a little endurance and patience.

Apply glue to the spatula with a trowel in the center of the tool. The number will be determined empirically. While applying the layer, hold the trowel at an angle to the foam boards, press down with medium pressure. Aim for a layer thickness of approximately 2–3 millimeters. Do not prepare a large amount of surface at once, for beginners, two meters in dyne is enough. If you do not have time to fix the mesh, the glue will harden, you will have to remove the old layer and make a new one.

Step 5. Try on the location of the plastic mesh reinforcement. If it doesn't fit into the window opening, trim the material.

Step 6. Glue one end of the mesh, align it horizontally to the length of the prepared wall section. Make sure that the mesh lies flat without distortions and bends, focus on the previously drawn line on the foam.

Practical advice. The mesh should overlap about ten centimeters. You can find recommendations to not smear the place of overlap of one line with glue, but to do it simultaneously for two rows. We do not recommend doing this, it only complicates the work. Glue the first row of mesh over the entire width at once, including the overlap. The second line will be glued on top of the freshly applied glue. This method simplifies mesh fixation and has a positive impact on quality.

Step 7. Use your hand to press the mesh against the fresh adhesive in several places, check its position again.

Step 8. With a spatula, start pressing the mesh to the surface of the insulation. Make sure that the glue of the first layer protrudes over the entire surface and evenly covers the mesh cells from the front side. If there are places with insufficient adhesive thickness, reapply it over the mesh. Such passes may appear for inexperienced craftsmen. Over time, you will learn to determine the optimal thickness of glue by eye and there will be no more gaps. Smear excess solution on free surfaces. You should not try to immediately make the surface perfectly flat, but you need to strive for such a result.

Step 9. Allow time for the glue to dry. It is better to leave it overnight, it is recommended to finish grouting the surfaces the next day.

That's the whole technology, the surface of the front wall is prepared for painting or finishing with other materials. We remind you once again that the plastic mesh on insulated facades is used not to prevent cracks on the glue surface, but from mechanical damage to the foam. Keep this in mind when making your decision.

Prices for popular types of putty

Putties

Facade mesh to protect the construction site

Compliance with safety measures during construction work on multi-storey buildings is one of the main requirements for all developers. This is especially true for objects being built within cities. The facade mesh is fixed on the scaffolding and prevents debris and tools from falling onto pedestrian walkways. For such purposes, the cheapest of the plastic reinforcing nets is used; after dismantling, it is suitable for direct use.

"Izumrud" - a new net for scaffolding

Question answer

Is it possible to repair exfoliated areas with a reinforcing facade mesh? It is possible, but it is better not to allow such situations. Unfortunately, in most cases, delaminations appear several months or years after the finishing of the insulated facade walls.

How is the repair done?

1. Inspect the exfoliated area. Use your hand to check that the mesh is firmly fixed next to the delaminated area. Prepare materials: glue and a piece of plastic reinforcement mesh. If the facade walls are painted, then you need to have the appropriate paint.
2. Pull the detached mesh towards you and use a sharp assembly knife to cut it around the perimeter. Work very carefully to avoid damaging the foam. If the sect continues to flake off during cutting, great. You remove the entire problem area in this way, it would peel off over time anyway.
3. Cut out a new mesh for the patch, the size should be slightly larger than the cleared area for overlap.
4. Remove the old glue from the foam surface.
5. With a spatula, carefully remove the top layer of glue from the surface of the remaining mesh to the width of the new overlap. Apply the first layer of glue, sink the mesh into it and apply the second layer of glue.
6. After it dries, flatten it. Pay special attention to the docking point. It should be as flat as possible without sudden changes in height.

Everyone has probably seen new houses with a cracked facade - thread-like cracks or even pieces of plaster that have fallen off. The main reason for such consequences when finishing "wet facade" is the use of mesh that does not meet the necessary requirements.

Currently, the building materials market offers a large selection of reinforcing mesh. As they say, the eyes run up - and white, and blue, and green, and yellow, and orange. But - the color of the mesh does not affect its characteristics in any way and each manufacturer paints them to his own taste or by order of large consumers. For example, you can make a mesh even with your portrait - the main thing is that it meets the criteria that are necessary for its use.
Reinforcement meshes differ in density, breaking load, and alkali resistance - these are the main indicators to look for when choosing a mesh:

	Facade mesh parameters
	cell (mm)	density (g / m2)
	5 x 5	145	1500/1500
	5 x 5	160	1800/1800
	4 x 4	165	2000/2000
	8 x 8	320	3200/3200

And now in more detail:

• Density - shows the weight of the mesh and is measured in grams per square meter (g / m²). The mesh can be used on the facade if its density is at least 120 g / m². All meshes with a lower density are suitable only for interior work.
• It is necessary to understand that a mesh with a minimum density will not work if the surface is plastered above 2 floors - as a standard, up to 5 floors you can use a mesh with a density of 145 g / m2, and above - 160-165 g / m2.
  Fiberglass mesh with a density of 320 g m & sup2, also called Vandal-proof», Is used on basement floors to protect the plaster layer from mechanical damage and can serve as a base for facing with stone or tiles.
• Inseparable with density and such a characteristic as breaking load. It is measured in newtons per 5 centimeters (N / 5cm). But it is important to know not the unit of measurement, but the load indicator - for a mesh with a density of 120 g / m2 it is 1200-1300, 145 g / m2 - 1500, 160 g / m2 - 1800, 165 g / m2 - 2000, 320 g / m2 - 3200.
• Alkali resistance is an important indicator and the less the mesh is impregnated with a special composition, the more likely it is that in an alkaline environment, which is the plaster solution, the mesh will simply dissolve and will not fulfill its function - to keep the plaster from cracking. This indicator is not written on the labels, so it is imperative to ask the seller for a product quality passport.

Thus, when choosing a fiberglass mesh, we advise you to pay attention first of all not to the price, but to the availability of a technical certificate and a quality passport from the seller, because chasing cheapness can get big problems. And now let's estimate - one square meter of "wet facade" with work will cost you 1,700 rubles. The price of one meter of high-quality mesh that meets all the conditions, even if the maximum is 50 rubles, a mesh of questionable "content" will cost 25 rubles. Doesn't it greatly affect the price of 1 m²? And when the plaster collapses a year later, the alteration will cost 3500 rubles per 1 m² (taking into account the beating of the destroyed layer). It is easy to calculate that with a volume of work of 2 00 m2, with a grid saving of 25 * 200 \u003d 5 000 rubles, it turns out problem 3500 * 200 \u003d 700,000 rubles!

The presentation of the article is designed for those who are not for the first time holding a spatula in their hands. Therefore, the technique of applying facade plaster or glue for expanded polystyrene insulation is not explained in detail.

But photos of wet facades will perfectly demonstrate the difference in the technology of installing the plaster mesh in two ways, popular with folk craftsmen. This will allow you to calculate the feasibility of applying one method or another on various parts of the facade.

Wet facade - fiberglass mesh plastering technology

This is a lightweight, thin fiberglass mesh that is sold in rolls. It comes in a variety of colors (usually blue, white or green). Its main property is resistance to solutions with an alkaline reaction. Unlike heavy welded metal meshes, which are used when plastering brick walls, fiberglass plastering mesh is successfully used in the wet finishing of facades insulated with expanded polystyrene.

By purchasing such a mesh in the construction market, you can get a lot of useful tips and tricks from the "experienced" on how to use it better.

We will demonstrate two ways of attaching the plaster mesh when reinforcing a wet facade.

Technological method of fastening plaster mesh glass (for the pros)

The main steps of the construction of wet facades in this way.

We measure the length of the mesh from the roll, equal to the height of the wall section, which is being prepared for plastering.

We mix the plaster mixture according to the instructions on the bag. Instead, glue is often used for expanded polystyrene insulation boards, which makes sense, since the glue mixture has the highest waterproofing and hydrophobic properties.

The photo shows just such a mixture.

We apply a layer of mortar, 2 to 5 mm thick. This must be done as quickly as possible, along the entire height of the wall segment. We even out small (up to 5 mm) differences in the level of the wall, but we do not try to "withdraw" the influxes - it is too early.

Immediately apply the plaster mesh to the top of the wall, placing it strictly vertically.

Press the fiberglass into the plaster layer using the widest spatula available on the farm.

In one place, you need to make no more than 2-3 sweeping movements:

• press the mesh;
• cover the mesh in the "bald spots" with a thin layer of solution;
• bring the site under the general level of the wall - align.

Pros and cons of the method

Disadvantages of the method:

• the cut-off mesh “gets tangled underfoot” and is easy to get dirty;
• foam balls, escaping from the insulation layer, stick to the spatula and interfere with the application of the solution;
• it is difficult for a beginner to single-handedly apply a plaster layer to the entire height of the wall and apply the mesh strictly vertically to the wet layer.

Benefits:

• dry mesh is laid without folds;
• easily pressed evenly;
• many find it easier to get the wall out perfectly straight using this method.

An alternative way of attaching the plaster mesh (for beginners)

We cut off a segment from the mesh roll, the length of which will be equal to the height of the wall section plus 5-7 cm.
Using an assembly stapler, we nail the mesh to the upper part of the wall or to the wooden part of the roof using an allowance. The net should be fixed in a strictly vertical position.

We mix the plaster solution. Apply a layer of plaster mixture 2-5 mm thick directly along the mesh, trying not to leave empty spaces between the mesh and the insulation. You need to start doing this from the highest point of the wall, moving down. Slightly level the differences in the walls, but don't worry about perfect smoothness yet.

It is not necessary to apply the solution to the entire height of the wall - you can repeat the following steps in 2-3 steps, moving from top to bottom along the wall.

Grasping the bottom dry edge of the mesh, pull it towards you, completely separating it from the wall and the wet layer of mortar. Then let go without pressing and lay on top of the plaster.

Apply a small amount of the solution to a wide spatula and cover the mesh with it, moving your hand from top to bottom.

Smooth the wall with wide arcuate movements to make it as smooth as possible for painting.

Advantages and disadvantages of the method

• during operation, the mesh gets a little wet and becomes heavy, which makes it difficult to remove it from the wall surface (stretches, forms waves, wrinkles);
• the result at the exit may not please: it is difficult to achieve a mirror-like flatness of the surface, like that of the pros.

• pre-fastening the mesh allows you to break down the work into stages that are available for a beginner to complete, even alone.

On the feasibility of two technologies for mounting a wet facade

To master the technological method, first try sections of walls with a small height (under the windows, above the doorway). This will allow you to evaluate your strengths for applying the correct do-it-yourself wet plaster technology.

Is plaster reinforcement required?

Considering that in Russia it is customary in most cases to carry out repair work on conditions and this type of repair assumes, first of all, its compliance with European standards, in the future we will also point to the construction rules adopted, in particular, in Germany in relation to reinforcement of plaster.

Reinforcement of the inner plaster layer is made, as a rule, using plaster mesh... Its purpose is to reduce the effect of the underlying base on the finishing layers and to minimize the risk of cracks associated with the mobility of such layers.

The use of such a mesh is not expressly provided for by the current Russian building regulations. In turn, European standards, although they do not prescribe the reinforcement of the plaster layer without fail, indicate that the use of plaster mesh is possible in the case when it becomes necessary to reduce the risk of cracks in the plaster layer. At the same time, the reinforcement of the plaster layer within the meaning of European building standards cannot serve as a means to prevent cases of cracking caused by the impact of structural processes (for example, deflection of floors, shrinkage, creep of load-bearing structures or their deformation caused by temperature differences) (see DIN V 18550 p 4.3 paragraph 2 and item 6.3).

Reinforcement of surface finishing layers allows, among other things, to reduce visibility cracks, which, due to various kinds of processes, appear in the underlying layers.

In accordance with SNiP, the thickness of the plaster layer made with a gypsum mixture is on average 15 mm (which corresponds to European building regulations). Such plaster is applied in one layer... In the case of reinforcement of the plaster layer, the mesh is established (immersed) in a freshly applied and leveled plaster solution to a height of at least 2/3 of the entire plaster layer (for example, to a height of at least 10 mm with a total thickness of the plaster layer of 15 mm) without forming folds and even before the formation of a crust on the surface of the main layer is covered the next layer of plaster, having a height of no more than 1/3 of the total layer thickness (technology of applying "wet layer on a wet base" or "wet on wet") - thus virtually all plastering work is performed in one layer.

Plaster mesh is laid with an overlap not less than 100 mm (in the places where one structural element adjoins another - not less than 200 mm).

Reinforcement of plaster on the surface of the walls in most cases is not continuous, but only at the junction of various finishing surfaces and structural elements. When applying a plaster layer to the ceiling surface, it is recommended to reinforce the entire area of \u200b\u200bsuch a layer.

When facing the wall surface with ceramic tiles, the reinforcement of the plaster layer is not performed. At the same time, the thickness of the plaster layer in accordance with European standards is 10 mm versus 15 mm provided for the subsequent pasting of the surface with wallpaper or covering with paint layers.

Plastering work should be carried out on condition that massive the moisture content of the underlying base is no more than 8% (Russian SNiP) or the residual moisture is no more than 3% (V DIN, Germany).

Our Austrian colleagues at one time conducted a detailed study and found that in the case of using gypsum plaster in new buildings subject to structural deformations (for example, in the form of shrinkage), it is possible to reduce the risk of cracks on the surface of the plaster provided that the plaster is applied in the form of a layer of thickness 20 mm and its reinforcement with plaster mesh.

Currently, there are stacks of actual plaster and painting... The first one has a cell measuring 5 x 5 mm and is used to reinforce the plaster layer. The second has a smaller cell - 2 x 2 mm and is used when applying putty. In addition, in the Russian market, the so-called "cobweb" - fiberglass, which is also used to reduce visibility cracks that may form in the underlying layers.

When, as a rule, the "cobweb" is used. In this case, the reinforcement of the putty layers with a painting net is not used in most cases. However, such work can be performed additionally at the request of the customer or in the presence of such a task in the project.

If you have any questions - write! We will try to answer them.