How to make a mortar for plastering walls
Today we will analyze in detail how to make a mortar for plastering walls. We also determine where and what composition is best used. How to prepare a plaster mortar is one question, but there are also different surfaces and weather conditions, so you need to know the conditions for using different compositions and then make a purchase of the components. Also on the video in this article you can see options for how to make plaster.
The content of the article
Choose the desired solution composition
How to make a plaster mortar, we will consider a little lower, you must first understand what composition is suitable in your case. After all, you can do everything yourself, then the price of the material will be much cheaper.
You also need to properly prepare the surface. Before the start of kneading, you should make sure that the surface that you will eventually plaster completely corresponds to the prepared recipe.
Recommendations what plaster solution to choose:
- If you are going to carry out exterior facade work or if you need to work in a room with very high humidity, then for surface treatment it is better to use mortars with cement, just cement or cement mixed with lime.
- If the humidity in the building is at the normal level, then you can use lime-based mortar or a mixture of gypsum and lime for decoration.
- If the humidity level is minimal, and the treated surfaces are also made of stone or wood (see How to plaster a wooden wall), the most appropriate choice would be clay-based solutions.
Before preparing the solution, consider some of the nuances:
- All initial reagents must be sieved. For this, sieves are used, mainly with square cells (mesh sizes are either 3x3 or 5x5 mm).
- For the preparation of solutions the container must have a depth of at least one or two centimeters.
- When mixing the solution should achieve complete homogeneity, without large lumps, otherwise the solution will not stick to the surface being trimmed. For mixing use a shovel, preferably made of wood, with a total length of one meter.
- After kneading, the solution must be checked for stickiness.: Scoop a little of the resulting composition with a shovel and let it drain. If visually the solution is only slightly stuck to the tree, then it can be used in work. If the solution drains slowly, or adheres firmly to the shovel, then you need to add a thinner, but if it is so liquid that it does not attach to the surface at all, then you need to add the starting ingredients to increase the viscosity.
Cement mortar
Recipe: standard 2 or 3 parts of sand per one part of cement (see Cement-sand plaster: material features) The proportions of sand can be even greater (up to six parts per part of cement), but then weak bonds will form between the components of the mortar - this will make all subsequent work difficult.
How to prepare a cement mortar for plastering walls:
- pour sand on the bottom of the container;
- sprinkle with several cement layers on top;
- mix them until a homogeneous dry mixture is formed;
- gradually add water, stirring the mixture all the time;
- when the solution reaches the consistency of thick sour cream - stop the flow of water;
- to improve the adhesion of the plaster, you can add gypsum or PVA glue to the solution - all in small quantities. If you want to reduce sticking, you need to add a small amount of detergent, which will create a film on the surface of the particles of the solution.
Attention: with the addition of PVA, the solution is suitable for work only for one hour after mixing, then its working properties will begin to deteriorate. It is better to knead the solution in small portions, which can be quickly worked.
To obtain a suitable solution, it is necessary to dilute the mixture of dry ingredients with water in the correct ratio. To do this, water should be fed into the solution in small portions, each time thoroughly mixing the mixture.
You can determine the wrong ratio of liquid to mixture by the following indicators:
- Viscous solution - the mixture is saturated with moisture, but not diluted enough, so the solution has a thick state, or a lot of cement was originally laid. After drying, a layer of such a solution deposited on the surface will give a lot of cracks and quickly crumble.
- Liquid solution - excess water, leading to a lack of components that give the desired viscosity. Or, the mixture initially contains more sand than necessary. Such a mixture is not stable when dried and is highly susceptible to destruction.
So, the correct viscosity is determined - it should be like thick sour cream. But the rules that should go to surface treatment, as such, do not exist. The only thing that should be taken into account is the surface area and the thickness of the required coating layer.
Cement + Lime
Recipe: from three to five parts of sand are mixed with one part of cement, plus 0.7-1 part of a solution of lime:
- Quicklime is used to prepare the solution. Bookmark the lime in a metal container. Protect your hands, mucous membranes and eyes - the substance can cause chemical burns.
- Pour warm water on top so that the lime layer is completely flooded. And then close the bucket with a lid, putting something heavy on top - quicklime enters into a violent reaction with water, and this threatens a splash of hot liquid.
- After the completion of the reaction, it is necessary to strain the solution. Gauze will come off for this purpose. Give it a day to stand and it is ready to use.
- Prepare a dry mixture: mix cement with sand in a proportion of 1 to 3 in a mixing container.
- Then pour in the settled lime mortar and mix thoroughly.
Lime Based Solution
The recipe for making a lime mortar for plaster: three parts of sand are kneaded in one part of a solution of lime.
- It is necessary to extinguish the lime and prepare the lime mortar according to the above procedure.
- 1/3 of sand and a small fraction of water are added to the prepared solution. This is done to better mix the mixture. Grind the resulting mixture thoroughly, until the lumps completely disappear.
- The rest of the sand should be added in small portions, while pouring water into the tank.
- The solution will be ready when it acquires a medium viscosity consistency and will only slightly adhere to the shovel.
It is impossible to leave the solution for several days, it must be worked out completely on the day of preparation.
Lime + gypsum
Gypsum mixes with lime mortar one to three:
- gypsum is diluted with water until it becomes thick dough;
- lime solution is poured into the resulting mass and mixed thoroughly.
Attention: you need to take into account the fact that this solution is fixed in the first minutes after preparation, for no more than 5 minutes, and after 30 minutes it completely hardens. Therefore, this mass must be applied to the surface instantly quickly.
Clay solutions
The preparation of a solution with clay is similar to the method of mixing lime mortar.But one clay is extremely rarely used in cooking, because it does not have the proper performance characteristics. It is customary to mix cement, gypsum or lime additives in clay suspensions.
| Clay + cement | Recipe: 1 part clay slurry, 2/10 cement additives, 3-5 parts sand. |
| Clay + gypsum | Recipe: one part of the clay slurry is mixed with a gypsum additive (0.25 parts), then 3 to 5 parts of sand are added. |
| Clay + Lime | Recipe: one part of a clay slurry, 0.3-0.5 cement additives, then from three to five parts of sand. |
So:
- in all solutions, components that give viscosity are first mixed with clay, then sand is added in portions and everything is thoroughly mixed until a homogeneous mass is obtained;
- if you do not have the necessary professional skills, then you should limit yourself to the above recipes. And solutions with a variety of chemical components should be prepared only by specialists.
Caution: clay composition will be best for finishing wooden surfaces. It does not harm wood and protects it perfectly.
What solution to plaster - now you need to choose. There is an instruction, only the most important thing, always prepare the components with high quality. After all, with plaster, everything will be reflected on the plane. Never rush, look at the photo and do it right.
