In the process of carrying out repair and capital construction works, the question remains as to which plaster - cement or gypsum to choose. These binders remain in demand for leveling, preparing and lining surfaces before finishing decorative work. Each of these materials has its own advantages and disadvantages, so making a decision is not easy.
As the main guidelines should be highlighted:
- ease of installation;
- Operating conditions;
- cost;
- turnaround time.
Comparison by area of use
If you still cannot decide which stucco - cement or gypsum to choose, you should consider each of them. For example, the first is suitable for external and internal works, it is not afraid of moisture and temperature changes, it is often used to align slopes, walls and other surfaces. You can use the material even in basement and unheated rooms.
This mixture is also good because it is suitable for finishing in rooms with high humidity, as well as processing concrete structures, to increase its heat-insulating properties. This option is an ideal masonry mortar when building from a foam block and aerated concrete is carried out.
A distinctive feature of the cement mixture is high adhesion. In addition, the composition is high strength and durable. It is chosen during capital construction and restoration of old surfaces, which is important when the compatibility of materials. This factor is very important, because cement does not hold well on the following surfaces:
- painted planes;
- wood;
- plastic.
Application limitations
When deciding on which type of cement or gypsum plaster to choose, you should also pay attention to the fact that the first has some limitations in use. For example, this should include a complex application process and a long drying time. The work should be carried out in several stages. First, the material is sprayed, then sprayed, after it is rubbed and ground.
In order to get a perfectly flat surface, you should work hard, because not all masters have the necessary skills. But with gypsum such problems usually do not arise. It dries quite quickly, which cannot be said about the cement layer. This can take about three weeks, even under those conditions if you have applied a thin layer. The surface is porous, it is not suitable for decorative finishes and has a dark shade, which means it needs to be putty and further sanded. Cement mixes are not decorative. As an exception, formulations with special additives are used.
If you cannot decide which plaster - cement or gypsum to choose, you should consider both. The second is more plastic and does not shrink. The consequence is that it is an ideal option for aligning the internal walls. Drying is faster, and it is not necessary to putty on the wall, because the structure is smooth without it.
Why choose gypsum
The color of the plaster is white, it does not appear under the paint or wallpaper. Such a composition is in contact with coloring pigments, it can be chosen as an independent decorative finish, it can take the desired shape, so with it you can create three-dimensional patterns.
If you want to know which is better - gypsum or cement plaster, you should consider the features of both. For example, gypsum has a low weight, which means that it can be applied without the risk of overload. However, one should pay attention to poor water resistance, which does not allow calling the composition universal. Under the influence of moisture, gypsum begins to collapse, so the plaster is not used for outdoor work.
Key Features and Comparison
Among the advantages of cement plaster, durability and strength should be highlighted. Such a composition is well suited for finishing and restoration of external work, excellently withstands mechanical and other external influences. Such mixtures adhere well to aerated concrete, as well as to smooth surfaces like artificial and natural stone. Application can be carried out on previously plastered walls. This mixture is well suited for foam blocks, for example, for their masonry and decoration, and the consumption of porous material is minimal.
Cost and moisture resistance
It is impossible not to highlight the low cost. Cement plaster is 2 times cheaper than gypsum. This applies to finished compounds and mixed on their own. It is also important to take into account moisture resistance, which is the main advantage of the described solution. This property allows the use of cement plaster as a material for the decoration of slopes, lining of bathrooms, bathrooms and kitchens. Gypsum under the same conditions can be used only with a certain surface protection with tiles. This feature allows the use of cement compounds for outdoor use.
The temperature of their use varies from + 5 to + 30 ˚. A 10 mm layer takes about 13 kg per square meter. With manual application, the water flow is 0, 14 liters per kilogram. The aggregate grains have a fraction of 0, 63 mm or less.
When applied to brick or reinforced concrete, the minimum layer thickness is 5 mm. The maximum thickness for brick is 25 mm, for concrete or reinforced concrete - 15 mm. The time of use of the finished mixture is 2 hours. If it is important for you to decide which is better - cement-sand or gypsum plaster, you should also consider the characteristics of the latter. Among the main features it should be noted the ease of installation and the speed of work. Drying occurs 2 times faster than in the case of cementitious compounds. In this case, the layer thickness may be the same. Gypsum mixtures are easy to process, they are not subjected to sedimentary processes, and when hardening, cracks form in a minimal amount when compared with cement plasters.
Additional features of gypsum
The masters also need plasticity. Without much effort, you can apply the material to any surface, spreading it over the wall with the desired layer thickness. The load on the structure is low. It is also necessary to highlight vapor permeability and environmental friendliness. The plaster is breathable. It is safe for humans and favorable for the microclimate in the house. You may also be interested in heat and sound insulation abilities. The structure is light and porous. It retains heat better than others and prevents the penetration and spread of extraneous noise. Due to these properties, gypsum mixtures do not need to be reinforced. As an exception, layers from 50 mm are used.
Material does not drain from vertical walls; it maintains its shape well. Application reduces repair time. For work, special construction skills are not required. Reviews say that gypsum allows you to save money, because it is spent in a minimal amount.
Reviews about the features of the application. Gypsum cement application
Many consumers are wondering if cement plaster can be applied to gypsum plaster. From experience, this venture is not the best solution. Cement mixtures mainly act as base surfaces, since they are quite rough to use, so getting an even base under such conditions will be almost impossible, according to home craftsmen.
Cement plaster on a gypsum wall is also not recommended to be placed, since an alkaline reaction will occur upon contact with water. Cement is a strong base, and gypsum does not like alkalis. Theoretically, this option is possible, the cement composition can be laid on a gypsum wall, but when wet, the lower layer will lose strength, and the material on top will get a low laminar strength. Therefore, consumers emphasize that anhydride and gypsum substrates should be classified as complex.
If you are still worried about the question of whether it is possible to apply cement plaster on a gypsum wall, then you should take into account that during drying in this case there will be tremendous stress, this will lead to the tendency of the materials to tear the layer from the surface. Consumers say that gypsum is best plastered exclusively with gypsum.
Gypsum application on cement
Considering the previous example, you should have understood that delamination could occur during such work. You can work in reverse order. It is permissible to apply gypsum plaster on a cement surface. Gypsum will take moisture from the cement, making a chemical reaction impossible.
Gypsum plaster is not as durable as cement-sand, but it is stronger than lime plaster. These works have their own nuances. Gypsum plaster must be applied using a primer. For finishing gypsum plaster, it is not recommended to use tiles laid on tile cement glue, as this will also contribute to the destruction of the material.
Characteristics of gypsum-cement plasters
A mixture of gypsum and cement plaster is sold as a composition of the brand "Prospectors" MIXTER. The mixture has a gray color and is made on the basis of cement, gypsum, sand and imported additives. The material is used to level the surfaces of ceilings and walls inside the premises for various purposes. The degree of humidity can be any. The thickness of the applied layer varies from 5 to 60 mm. The average consumption of the mixture per square meter is 1.1 kg. The layer thickness in this case is 1 mm.