Common classification of mixtures and application stages
There is a sufficiently rigid system that allows you to scale the scope of each type of plaster mixture, depending on its composition, purpose and specificity of the work. By appointment, they can be special( insulating, protective), decorative or textured, and simple, their composition also differs depending on the expected binding properties and the manufacturer's specifications.
Before proceeding with the plastering work, it is important to study the building requirements and the norms of technologically correct operation with a mixture on different surfaces. Usually this information is available on an industrial package. The most important rule in working with any materials for leveling different surfaces is a layer-by-layer application and a natural drying of the applied solution.
The average thickness of the plaster layer for wooden surfaces does not exceed 20-25 mm, for brick and concrete - 10-25 mm. Apply the mixture gradually, systematically approaching the recommended thickness, in order to avoid solution sagging during drying or its cracking after final drying.
The number of layers and the technology of their application depend largely on the composition of the mortar and the quality of the finish, for each option the application process is different. The technology provides for three basic steps:
- for simple surface treatment, two layers are enough - spray and soil;
- for improved - three layers - spray, primer and cover;
- for high-quality finishing, in addition to the three main layers, an additional layer of soil must also be applied.
Surface preparation and maximum permissible thickness of decorative plaster
Decorative plaster mixture is the most difficult in the work, becauserequires careful preparation of the surface, which eliminates the cracks and crumbling of the solution after drying. Therefore, the process of surface preparation is a special sacrament. The first step is to clean the structure of excessive dirt and dust, remove the protrusions of cement, make sure that there are no vertical and horizontal differences in elevations. Then apply a basic coating.
After the drying of the base, the ground mixture should be scribbled. To improve the adhesion between the layers, the surface should be slightly moist, so do not allow the final drying of the base coat. After the primer has dried, you can make a notch on it, and then follow the instructions to apply the texture. The thickness of the decorative plaster layer depends more on the size of the filler grains and ranges from 8 to 17 mm.
Technology of applying the improved plaster mix
When working with improved plaster, the sequence of operations and the number of layers remain unchanged. To avoid cracking, swelling and peeling of the applied solution, it is necessary to follow the manufacturer's recommendations clearly and not to overmoisten, contaminate and exceed the recommended layer thickness. It is better to apply an additional primer if the surface is uneven and has a large number of drops and depressions.
Technologically acceptable thickness of the improved plaster for wood should not exceed 9 mm, 7 mm for calc-gypsum mortars and 5 mm for concrete, brick or stone substrates. After the application of the last layer, it is leveled with a half-wiper or ironing pad, then after drying it is rubbed with a felt or mesh grater.
Apply the cement plaster
The first draft of the mixture is applied roughly, the technology does not require a careful leveling of the surface. Before applying the next layer of the solution, the base layer should be allowed to dry, it takes from 18 to 36 hours, depending on its thickness. Working with a cement mixture, it is not necessary to strive for a perfectly flat surface, as, as a rule, this kind is used for finishing auxiliary, storage and basement premises.
In residential and general use areas, cement plaster is not used as a finishing coat, it is usually necessary for removing surfaces for laying tiles or for applying construction material.
It should be noted that the thickness of the cement plaster should not exceed 10-20 mm, each layer must be thoroughly dried before the next one can be applied. With strict adherence to all the manufacturer's recommendations and building codes, you will achieve the desired result and can easily prepare the surface of walls or ceiling for painting or tiling.