Monolithic wall decoration, regardless of the type of material used, will always win in terms of reliability and durability over the restored defective surface. But it is far from always justified to completely dismantle the old coating for applying a new one, therefore, restoration measures should not be abandoned. The most common operations of this kind include grinding plaster. What is this operation? This procedure is in the nature of a minor repair in the form of sealing a damaged finish. Accordingly, it has its own characteristics and nuances of execution.
Grinding features
This technique can be compared to a partial primer or spot restoration of a defective area. But if shallow flaws can be de alt with with putty with a light grout mixture, which will also provide a leveling effect, then grinding aims to repair deep damage, but with a smallarea. Does this mean that the work is being simplified? In a sense, yes, because the volume of laying can not be compared with the complex design of the walls with a new coating. On the other hand, the restoration of individual sections always entails a violation of the surface geometry - the same threat is especially evident during the grinding of plaster. What does it mean? Placing a thick layer of mortar in a small area can cause problems when correcting the surface. Accordingly, the accuracy of applying the mass and further alignment will be important. The problem is that mechanical alignment may not give the expected result, since the fluid mixture after work is still deformed under its own load.
Preparation for work
Responsible stage during which the target workspace is prepared. The surface is cleaned of dust, dirt and other foreign particles. Light sanding can also be done to remove loose layers of old remaining plaster. It is not worth overdoing this operation, since strong fluctuations can affect the structure of the adjacent solid coating. If, after stripping, elements of metal reinforcement appear outside, they should first be sealed with a special putty that can be used in contact with metal surfaces. It will also be important to have such a quality as the adhesiveness of grinding the plaster of the interior. This is a property that determines the adhesion of the new mortar layer to the base surface. Just as removing dirt from the damaged area improves adhesion, so doesof the laid putty should, at least, organically interact with the solution of the applied plaster. However, the choice of a suitable mixture should be given special attention.
What solution do you need?
The main question in choosing a dry mix for grinding is what should be the type of base? It is better to refuse modified compositions immediately, since the plasticizers included in them in small areas in direct contact with a foreign mixture can manifest their qualities in different ways. After all, do not forget what grinding of plaster means? This is the incorporation of a new solution into an already existing coating structure. A universal option may seem to be a traditional cement composition, in which both adhesion is high and strength will make it possible to form a reliable seal. However, the cement-sand mixture has a long curing period, which is an undesirable characteristic for a mass laid flat in a small area.
Gypsum mortar will be the best solution. In addition to environmental friendliness and fast hardening, such a base will make it possible to perform plastic and shrinkage-resistant grinding of plaster. What will it give in practice? Firstly, it will remove the problems of post-processing damage, when it will be necessary to perform leveling and corrective operations. Finishing is performed once, after which the laid mass is not deformed. Secondly, gypsum will allow you to repair even complex and hard-to-reach areas precisely because of its plasticity. In some conditions, such plaster can be used as a substitute for putty.
Grinding technique
It is desirable to perform the operation manually with a spatula with a small rule for surface correction. After 2-3 hours after laying the base mass with complete sealing of the defective area, with the help of a lattice grater, sags and all kinds of irregularities should be removed. By the way, wall plaster grinding can be done in several layers if the embedment depth exceeds 25 cm. In this case, the first layer should be applied without intermediate treatment. Moreover, to increase adhesion with the subsequent layer, the initial surface should be made rough. And after the second pass, the excess is removed and the texture of the coating is leveled.
Regrinding in combination with jointing
If you need to make a deep sealing of the crack, it is desirable to perform preliminary jointing. This is a kind of cleaning, but in a more in-depth technological version. The jointing procedure consists in removing the remnants of the problematic concrete along the edges in the crack zone. Finishers are advised to blow out the defect cavity itself as much as possible, which will stop its further spread. In the process of grinding plaster with jointing cracks, a chisel with a hammer is used to remove the old finish and a construction vacuum cleaner to purge the fracture. The rest of the operation is performed according to the standard mortar laying pattern.
Features of outdoor work
Repair of the facade coating has its own specifics,for which the following corrections are made:
- The solution must be made on a composition intended for outdoor use. In particular, the silicate filler will allow you to perform high-quality grinding of facade plaster. What does this mean in terms of operational impact? At a minimum, protection from precipitation will be provided with strengthening the structure of the problematic coverage area.
- Do not apply plaster on a dirty surface. To clean the facades, a special high-pressure washer is used.
- Sealing is carried out with a mandatory preliminary primer in 2-3 thin layers. At the final stage, the leveling of the plaster can be done with a waterproof sealant.
Conclusion
As a repair and restoration operation, grinding allows you to save the overall structure of the base coat for some time, but you should not overestimate it. The heterogeneity of the finish structure in itself creates favorable conditions for the future formation of new cracks. Therefore, experts use the concept of temporary grinding of plaster. What does it mean? Repair of damages and defects of the coating is carried out only for a certain period until the next overhaul. Otherwise, there is a risk to detect signs of the same cracks in the place of grinding through a new decorative finish already in the first months after work.
