Outdoor gypsum plaster - step by step instructions!

Plastering is a complex of construction works, which are among the most difficult. They include many nuances that are known to professionals, but incomprehensible to beginners. Therefore, for the correct execution of plastering work, it is recommended to use step-by-step instructions for each stage of interior and exterior decoration.

Features of gypsum plaster

Modern plaster mixes are of two types: cement-based and gypsum-based. The former are traditionally used for external and internal decoration of non-residential and residential premises.

But with the advent of gypsum mixes, priority was given to them. This is due to the numerous advantages of these materials.

The only reason for using cement-sand compositions is a high level of air humidity. The fact is that gypsum material is hygroscopic, and gradually collapses under the influence of moisture. In the mixtures intended for the production of facade work, special additives are introduced that increase the moisture resistance of gypsum.

But the application of such plaster has its own nuances.

If you plan to finish the facade with artificial stone or porcelain stoneware, you can not use gypsum as a binder. For laying this finishing material, mortars are used exclusively on a cement basis.

The advantages of gypsum plaster

Gypsum plaster is a real gift for a beginner in this type of finishing work. With such a mixture, you can not be afraid of flaws, since almost any flaw can be corrected later.

This will help the pliability of gypsum plaster for processing. If the cement needs to be knocked down, the gypsum can be cut off or ground off with a sharp spatula.

It is important to consider: do not confuse the plaster composition with the filler. The first is designed to eliminate flaws in surfaces, the second is for sealing cracks and finishing plastered walls.

Modern gypsum plasters are able to provide perfect surface evenness without additional use of starting and finishing mixtures .

.. This allows you to save on the purchase of materials for finishing work.

The advantages of gypsum plaster include:

• ecological purity provided by the natural origin of gypsum;
• the absence of toxic substances with a specific odor in the composition;
• high level of vapor and gas permeability;
• no shrinkage.

The complex of these advantages ensures the comfort of the microclimate of the premises, the decoration of which is made with materials based on gypsum.

General rules for the use of cement and gypsum mixtures

1. Plaster is essential for leveling surfaces and repairing imperfections such as chips, gouges and cracks.
2. The optimum layer thickness for application is 5 to 50 mm.
3. Regardless of the composition, you will need to consistently perform a number of works: prepare a solution, install beacons, reinforce the layer (if necessary), leveling and finishing.

According to the joint venture, the finishing layer must have less strength than the base on which it is applied. When using cement-sand mortars, this rule is often violated, since such plaster is much stronger than gas or foam concrete, dilapidated wooden surfaces.

This leads to cracking and peeling of the finishing layer. The use of "breathing" gypsum plaster eliminates the appearance of such unpleasant consequences as micro and macro cracks.

Composition and types of gypsum plaster

The basis of mixtures of this type is an environmentally friendly binder - gypsum. In addition to it, various fillers and modifying additives are included in the composition, providing the plaster with plasticity and high adhesion (adhesion) to any surface, smooth or rough.

The water-soluble polymers required to improve the performance of the coating are supplied to the Russian market from Europe.

Water-soluble pigments that are part of mixtures for facade works, most often of domestic production. As a filler, ground sand and polymers are used.

Depending on the section of the granules of these ingredients, three types of gypsum-based plaster mixes are classified:

• fine-grained;
• medium-grained;
• coarse-grained.

Fine-grained mixtures contain crushed sand, so this plaster is more fragile. This determines the rule for its application: the layer thickness should not exceed 8 mm.

Otherwise, after drying, cracks may appear on the wall.

Medium-grained gypsum plaster is most in demand for interior work. It can be applied in a layer, the thickness of which does not exceed 5 cm. Coarse-grained and medium-grained mixtures are used for facades. Compositions with large section filler can be applied in a layer up to 8 cm thick.

Prices for various types of gypsum plaster

Gypsum plaster

Mixes for manual and machine use

Gypsum plasters are also distinguished by the method of their application. According to this criterion, two types of formulations are classified: for manual and machine application.

Mixes of the first type are distinguished by a large number of chemical additives, since their main task is to provide the optimal time for manual batch production. The introduction of chemicals into the composition allows to increase the time for the onset of setting of the solution to 40-60 minutes. Thus, in just 4-5 hours, a full cycle of work on external or internal finishing of buildings and premises can be completed.

Gypsum plasters intended for machine application have different tasks.These compositions should differ in a longer setting period (from 1.5 to 2 hours), since the master needs to process a significant amount of surfaces during this time. The work is carried out in two stages: applying a plaster mixture to the wall with a special gun and leveling this layer. The long setting period of the composition guarantees that the master will have time to complete the full cycle of the tasks required by the technology.

Gypsum is fed into the gun through hoses connected to a specialized machine for preparing wet plaster from dry mix. For better mixing and ensuring the smooth passage of the solution through the hose system, fractionated (crushed to particles of a certain section) sand is added to the mixture.

Manufacturers of gypsum plaster

The choice of gypsum plaster is not an easy question. Visiting a building materials store, you can easily see how great the variety of brands is. In order to simplify the selection process, you need to understand that the main gradation of mixtures is according to the type of their application.

There are only two of them:

• for outdoor work;
• for indoor work.

All, without exception, manufacturers offer a range of mixtures of both types. Having decided on the purpose of the product, they choose its brand. The most popular brands have a higher value. But it should be understood that there is nothing special in the composition of these plaster mixes: all manufacturers use the same ingredients.

The price is often determined only by the degree of brand awareness. And this indicator directly depends on how much the manufacturer spends on advertising its products.

The most popular brands:

• Henkel;
• Knauf;
• Atlas;
• Ivsil;
• Unis.

The Knauf company produces gypsum plasters "Rotband" and "Goldband", known for their plasticity and ease of application.

Henkel offers products under the brand name "Ceresit". In a wide range of building mixtures of this manufacturer there is also gypsum plaster, but the company pays the main attention to the development of a line for the production of mixtures for decorative finishing of premises. Some foreign brands (for example, "Rotband") are produced at Russian enterprises under license.

Among domestic manufacturers of gypsum plaster:

• "Volma ";
• Perfekta;
• " Keraflex ";
• " Prospectors ";
• " Bolars ";
• " Foundations ";
• "Glimes";
• "Eunice".

The Volgograd gypsum plant offers products under the Volma brand.

But only two types of mixtures on a cement-sand base are intended for finishing facades. A more solid list of compositions for outdoor work is offered by the Polish concern "Atlas".But in its assortment there are also no gypsum mixtures for facades.

It is difficult to provide a complete list of gypsum plaster manufacturers: these products are produced by many domestic and foreign enterprises.

Selection rules

The cost of products of domestic enterprises is much lower than foreign ones.

But this does not mean that the gypsum plaster mixes from Russian manufacturers are of low quality. Most often, there is not much difference in the technical and operational characteristics of the products of different companies. There is little difference in formulations and percentage of ingredients.

The quality of gypsum plaster is determined by the amount of additives included in it. If this figure exceeds 30% of the total volume of the mixture, manual application will be difficult.

The reason is that a significant amount of additives reduces the adhesion of the plaster, so it will slide off the wall during application. Such mixtures are best used for work using special machines. In this case, the plaster will be "driven" into the surface of the wall, thanks to the pressure of the spray from the gun.

Features of the use of gypsum plaster for facade work

Gypsum has a high coefficient of water absorption, therefore, compositions based on it will inevitably be hygroscopic. Thanks to polymer additives and mineral plasticizers, it was possible to increase the level of moisture resistance and frost resistance of plaster mixtures.

However, this is not enough for a full-fledged facade decoration with gypsum compositions. To use these materials, additional protection of the walls from moisture is required.

Gypsum plaster can be used for outdoor use only as an intermediate layer, provided that the facing will have good steam permeability. For this reason, despite all the advantages of gypsum compositions, they are rarely used for facades.

Mixes for outdoor use, in addition to the main binder, should include additives such as gypsum polymer or HPCV ( gypsum-cement-puzzolanic binder).

In this case, gypsum plaster will acquire properties that provide proper resistance to adverse environmental influences. But all manufacturers of gypsum-based compositions warn that their products are intended only for interior decoration. This is another reason for the uncertainty about the suitability of gypsum plaster for facade work. However, for regions with a dry climate, facade mixtures can be used fearlessly.

Technology for leveling walls with gypsum plaster

Tools and materials for work

The first thing you need to learn is the correct mixing of the plaster mortar.

In our time, manual preparation of the batch is irrelevant.For this purpose, you can use a drill (turning on the low speed mode) and a special attachment: a metal mixer.

In addition to these tools, you will need:

• clean and deep enough container (basin or bucket);
• spatula with a wide blade (60-65 cm);
• rule;
• trowel;
• beacons (perforated aluminum profile);
• grating board;
• sanding mesh.

If the walls intended for plastering are built of concrete or brick, to prevent the formation of cracks, use a special sealing tape with a width of at least 2.5 cm, which is glued vertically every 40-50 cm.

Prices for popular drill models

Drill

Rules for the use of plaster mesh

Gypsum plaster is highly resistant to cracking, therefore, when using it, no preliminary reinforcement of the base with plastic or metal meshes is required. The only exception is the coupling of different materials from which the adjacent walls are erected (for example, from concrete and aerated concrete). In this case, the use of plaster mesh is justified.

But the mesh is glued only into the corner, which is the junction of dissimilar walls. Moreover, it is not fixed directly on the surface of the base, but in the middle of the plaster layer.

In this case, an overlap on each wall of at least 15 cm should be provided. Plaster mesh is also used to strengthen window and door openings. In this case, the canvases of this material are glued diagonally.

Rules for the preparation of walls

The surface of the walls must be cleaned of the remnants of the old finishing material.

Remove all dust and dirt with a vacuum cleaner and dry cloth.

Prices for front primer

Front primer

Stages of work

Step 1. Apply the primer.

A regular paint brush can be used to apply the primer for small applications. But this is a long-term and laborious process. It is much easier to spray the wall with a spray gun.

However, gardening is not recommended for use, as a large overrun of the primer is obtained, which will merge from the walls to the floor. If there is no special tool for spraying walls, the best choice is a brush-brush.

The primer is applied in layers until it stops absorbing into the walls. For foam and aerated concrete, a 5 and 6-layer coating is required. If the surface is not sufficiently saturated, most of the moisture will be absorbed by the wall during plastering, which will lead to premature drying of the mortar.

Step 2.Mixing the solution:

• pour clean water into a container with a volume of 60-65 liters (a bag weighing 30 kg requires 17-18 liters of water);
• pour it into a container with water 1/3 bag of dry mix and mix the composition thoroughly (for manual application, much less water and dry mix is ​​required for one batch);
• add the remaining dry plaster in the bag;
• stir the solution using a drill and mixer.

When preparing a smaller volume of the mixture, follow the manufacturer's instructions. The ready-to-use solution should have the consistency of thick sour cream and should be a homogeneous mass without lumps. Thus, any gypsum plaster from domestic or foreign manufacturers is kneaded.

Step 3. Protection of window and door openings.

Window and door openings are covered with cloth or plastic wrap.

Step 4. Installation of beacons:

• beacons are installed at a distance less than the length of the rule;
• plaster is applied to the wall so that her sculpts formed vertical lines;
• press the beacons into these protrusions;
• align the beacons with a level so that all profiles are located in the same plane.

Step 5. Plastering over:

• scoop up the solution from the container with a trowel;
• with a sharp movement of the hand away from themselves, throw the plaster on the wall;
• fill the space between two adjacent lighthouses.

Start the plaster cast at the left corner for right-handers, and right for left-handers.

It is important to know: when working with gypsum mixtures, those surpluses that have been removed from the walls must not be thrown into a container with an unexploited composition. These lumps are capable of provoking an acceleration of the hardening of the composition, which will lead to overspending of the dry mixture.

Video - How to sketch plaster

Step 6. Leveling the plaster.

For the first leveling of the plaster, only the h-rule is used. Its wide working part allows it to be manipulated like a spatula.

The trapezoidal rule will make it much more difficult to achieve the desired result.

Masters advise not to pull the rule necessarily from the bottom of the wall, but to start alignment from the middle of the sketch, gradually capturing its entire lower part. The material that remains on the rule after alignment is filled in all the places (sinks) that require rework.

Step 7. Smoothing.

Smoothing of the plaster layer is started at the moment when the mixture has already begun to set, but at the same time it is still quite soft.

To determine the readiness of the solution, press it with your finger.If a small depression remains, you can start smoothing. At this stage of work, a facade trowel with a blade width of 600 mm is used.

Move the spatula with slight pressure diagonally or horizontally. The vertical direction often removes significantly more surplus than required.

This leads to the formation of waves.

Step 8. Removing beacons.

Carefully remove the profile from the plaster layer, trying not to dislodge the mixture that has not yet set.

Step 9.

Sealing the recesses after sampling the beacons.

The resulting cracks are filled with plaster solution, it is leveled and smoothed.

Step 10. Finishing grout.

When the plaster begins to dry and acquires a matte shade, the wall is moistened abundantly with water using a soft sponge.

Then they take a spatula with a wide blade and perform the final leveling of the surface. Particular attention is paid to the places where the lighthouses were installed.

If the differences in wall heights were significant (over 5 cm), plastic or metal plaster is placed between the layers of plaster mesh. The overlap of the canvases should be at least 10 cm. If you adhere to the proposed work technology, the finishing work will be performed with the highest possible quality.

Video - Gypsum plaster for outdoor use

Video - Plaster and corner reinforcement