Ideal walls: cement plaster
The owners of the apartments are so accustomed to the fact that the rooms have uneven walls, which, when planning a repair, necessarily enter the item “alignment of the walls”. This type of work has long been customary both for professional teams and for independent execution. In order to thoroughly understand the offers of the building materials market, one must be a high-class specialist, since the range of mixes for leveling and plastering the walls is very large.
But there is material that has been used for these purposes for many years and has still not lost its popularity - cement plaster.
What is the secret of cement-sand plaster? This is completely obvious. The main selection criteria for buyers have always been the following parameters:
- material strength;
- durability of the material;
- ease of preparation for work;
- resistance to moisture;
- acceptable price.
Cement plaster meets all the above requirements.Isn't it a reason to use such wonderful material in the future?
You will be surprised, but it is not necessary to buy ready-made cement mixes. If you wish, you can mix the components for the rough finish of the walls. To do this, you just need to know what the cement plaster consists of, the proportions of the components and the amount of water.
So, write down the “recipe”: 3 parts of sand is mixed with 1 part of cement, and water makes up about 20% of the mass of dry materials. It is difficult to specify the exact amount of water, since solutions with different consistencies are used for different needs.
Everyone understands that building materials that do not have flaws do not exist in nature. There are some drawbacks to cement-based plaster. The main one is considered low plasticity of the material. However, craftsmen have long guessed how to improve this figure. If cement plaster is mixed with PVA glue, then its plasticity becomes much higher. In fact, the adhesive plays the role of a polymer that improves the adhesion and elasticity of the material.
Slaked lime is considered another popular additive to cement-sand mixtures. It is most often added when it is necessary to perform work in damp places.Such an additive makes the mixture easier, the material remains ductile longer, increases resistance to cracking and vapor permeability.
What is included in store mixes
Why do manufacturers spend time and production capacity to produce ready mixes based on cement and sand, if you can sell components separately and not spend money on the development of production? The fact is that in the finished mixture includes additional components that improve their properties. The latest developments in this field are various polymers and copolymers. These additives have the following properties:
- increased strength due to the appearance of an elastic film that improves the flexibility of the suspension;
- impact resistance increases as the polymer is plastic;
- hydrophobicity is manifested, that is, the tendency of the molecules of the mixture to avoid contact with liquid, thanks to this property, water does not penetrate into the plastered wall, but is collected by drops on the surface;
- internal links are strengthened, thereby increasing the resistance to abrasion of the material;
- increases the number of freezing / thawing cycles of the material.
In addition, the finished cement plaster boasts a higher quality of raw materials. Sand for this purpose is specifically calibrated and washed, there are no excess impurities, which improves the final result of the work.
How to calculate the amount of material
Depending on the curvature of the walls, which must be corrected, it is necessary to calculate the consumption of cement plaster before starting work. Carefully read the manufacturer's instructions. The package indicates how much dry mixture is needed for finishing 1 m², if the layer is 1 cm.
Knowing the layer thickness, for example, is 2 cm, it is necessary to multiply the amount of the required mixture by 2. This is the amount of the mixture by 1 m², which must be multiplied by the area of the wall. Since the curvature of the wall makes the plaster layer uneven, the amount of material is calculated approximately, not exactly.
You have learned how to mix cement plaster with your own hands, determined that the homemade or commercial mix is more qualitative, calculated the material consumption, and now it's time to figure out another little trick.
The life of the cement plaster will increase significantly if the plastered surface is treated with an acid-containing mortar. For this purpose, special formulations are used for dressing.This is a dangerous job and it must be done in the means of protection. Acid suspension is spread on the wall with a roller or brush, and after drying, wash off with water. In addition to increasing the service life, pickling plaster will prevent the occurrence of mold and mildew.