Plastic plaster grid: material features
Just a couple of decades ago, builders and finishers puzzled and went to all sorts of tricks to achieve not only a perfectly smooth plaster surface, but also durable. Many different methods were invented, but, unfortunately, all of them left much to be desired.
Until the plastic plaster grid appeared on the construction market, which in one moment solved all the problems, and it is about her that we will talk in this article.
The content of the article
What is the mesh for?
This question is traditionally asked by repair customers to builders, and this is quite justified, because before there was no trace at all, however, the walls were plastered and the solution somehow stuck.
But try to remember how many years have passed before small cracks, or even just falling off pieces of plaster, began to appear on the walls? Five, ten? It is unlikely that, as a rule, the first signs of destruction on unreinforced plaster appear after 2-3 years.
Many people are accustomed to blame workers or cement of poor quality for this, but this is not so, just most of the stucco mixtures have the peculiarity of shrinking after complete drying, plus microscopic movements of the walls, and as a result, the walls are falling apart and the need to make new repairs.
In order to somehow improve the situation and extend the life of the plaster, builders came up with two ways:
- To make a crate of small boards on the wall. The technology was called - shingles.
- Leave notches on the wall with an ax.
The first method seems more effective, but in fact it is not, since the tree absorbs moisture very well and at the same time expands, but dries out, decreases again. Thus, shingled plaster not only does not increase the service life of the coating, but often also reduces it.
As for the notches on the wall, this method is designed to increase the adhesion of the mixture to the wall due to surface roughness, and this method really works, although it prolongs the integrity of the plaster layer for a very short time. Today, both of these methods are in the past, as plaster plastic mesh appeared on the construction market, and this completely changed the attitude towards stucco walls.
Here, the plastic stucco mesh acts as a reinforcement, it holds the stucco mixture together and prevents it from scattering and cracking. The coating is completely monolithic and does not need additional strengthening. The walls on which the plastic stucco mesh was used, maintain their integrity much longer, even if we talk about the facades, which are exposed to many factors from day to day, from natural influences to banal, mechanical stress.
Advantages of plastic mesh
So:
- The plastic grid for plaster differs from its metal counterparts in light weight, which does not create additional load on the walls, which means that it can be used not only on main walls, but also on light partitions.
- Relatively low price, for example, a 5x5 plaster grid plastic, costs only 15 rubles per square meter.
- Due to the fact that the grid is sold in rolls of about 10 meters, a large amount of area can be covered at a time, This is especially true if the repair is done with your own hands and without assistants.
- Unlike metal, the plastic plaster grid does not rot, and therefore, does not give corrosion spots that could appear on the surface.
- High density mesh is able to withstand up to 5 centimeters of plaster layer.
Important! Depending on the thickness of the plaster, the mesh can either simply be recessed into the starting layer or attached directly to the wall with anchors or dowels.
Of course, this material is not perfect, and it also has its own set of shortcomings that have to be reckoned with if there is no desire to redo the repair every few years.
disadvantages
So:
- Despite the fact that plastic is resistant to most types of solvents used during repairs, it is very afraid of alkali, which is found in large quantities in cement.
- Compared to metal or fiberglass (see Fiberglass plaster mesh - types and scope) competitors, the plastic plaster grid has the lowest tensile strength, so if it is supposed to make a plaster layer more than 5 cm, it is better not to use this material.
- Any plastic has small thermal expansions and deformations, which can affect the quality of the coating.
As you can see, there are also disadvantages, and some of them are very significant, therefore, before choosing a plastic mesh, you need to carefully study all the nuances of the wall where it will be used.
Types of Plastic Mesh
It would seem that plastic, it is plastic, and how can it differ? But no, modern manufacturers of reinforcing mesh try to satisfy the desires of all consumers, regardless of what tasks they set. That is why, a plastic grid plaster can differ not only in a wide color gamut, which in principle is not so important if it disappears under the plaster, but also in the degree of density.
From this indicator depends on what maximum load can be sustained by the plaster layer. Also, the grid density parameter shows what maximum thickness a plaster layer can be.
The variety in density is very extensive, and in principle, you can choose a grid accurate to the centimeter of the plaster layer, but, as a rule, all such calculations are approximate, and the maximum value is taken as the main value, so there are three main ones from the most popular plastic mesh models:
- Density 70 kg per cm2 withstands plaster layer up to 30 mm inclusive.
- 145 kg per cm, with a load of 3 to 5 cm.
- 165 kg per cm, with a plaster layer thickness of more than 5 cm.
Advice! When choosing a grid, one should always consider not only the error in the calculations, but also the margin, which should be about 20-30 percent. This is done in case of unforeseen situations and possible differences on the walls.
But not only density and color can distinguish plastic nets. Another parameter is the mesh configuration. At first glance, it might seem that this parameter, like the coloring, does not make sense, and really, what difference does the grid look like if it is hidden by a thick layer of plaster anyway.
In fact, the answer is simple - wall reinforcement, this is just one of the popular purposes of this grid. In recent years, it has been used more and more often as temporary fences on a construction site and even in summer cottages as a permanent fence, and this is where the aesthetic component is very important.
By the difference in cell shapes, the plastic mesh is marked with Latin abbreviations:
- SQ - grid with square cells.
- PCF - diamond shape.
By the way, the option with rhombic cells is considered more preferable for plaster, since such a mesh is easier to fix with anchors.The fastener cap is fixed in the upper corner of the rhombus, and the net does not move out of place. This is especially true when there is no assistant who would support the grid during installation.
To summarize
The installation of a plastic mesh is no different from the installation of a metal or composite, so we will not dwell on this issue in detail, but for clarity, we will present a video in this article, which shows detailed instructions for installing the mesh and for plastering.
As for the use of plastic mesh, as can be seen from the foregoing, it is best to use it indoors, where there are no large temperature differences, and plaster mixes are not so aggressive.
If we talk about the decoration of the facade, then it is better to pay attention to more durable and stable options, such as fiberglass. Of course, a composite mesh has higher technical characteristics, but it also costs much more, and for internal work its performance is too high, so plastic is considered an ideal option.
