You can level the walls before finishing the room with plaster. This method of pre-finishing the walls has a number of undeniable advantages: the low cost of the material and the ability to do all the work yourself. Even a person far from construction can master the technology of plastering walls in just a matter of minutes. The main thing is to know the maximum thickness of the applied material when finishing the walls. The material of the surface on which the work will be carried out is also taken into account.
Varieties of plaster
For interior decoration, several types of mixtures are used. They differ in their composition and intended use. Plaster compositions can be classified as follows:
- Simple. It is used in cases where special finishing is not required. It is applied to the wall in two layers.
- Improved. Good for wallpaper. Such plaster is applied to the wall in three layers - spraying, priming and covering.
- High quality. Used to prepare walls for painting. It is applied in several layers. In the process of work, it is recommended to use special beacons.
According to its structure, plaster can be wet or dry.
In the first case, it is a cement-containing mixture that reliably adheres to the surface. It is undemanding to the level of humidity in the room. Among the shortcomings can be noted the long drying of the material.
Dry plaster is more convenient to work with. It consists of gypsum or lime mixtures. The disadvantages include the exactingness of the material to the humidity of the air in the room.
Thickness for various substrates
It should be noted right away that the mortar layer on the wall should be minimal. Excessive thickness will cause the plaster to crack under its own weight. Consider what should be the maximum thickness of the plaster on specific examples.
Brick
For brick walls, a certain relief is characteristic, so the minimum amount of mortar should be 5 millimeters. Applying less does not make sense, as there will be problems with leveling the material. The maximum value can reach up to 5 centimeters. For such a thickness, it is necessary to use a reinforced mesh. The maximum allowable layer of plaster without a grid should not exceed 2-2.5 centimeters.
concrete base
Due to its structure, concrete adheres well to any finishing materials and has a fairly even surface. The thickness of the plaster for concrete walls starts from 2 millimeters. The maximum throw of the solution without using a grid is possible up to 20 mm. With reinforced mesh, the thickness can reach 7 centimeters.
Aerated concrete blocks
In their structure, these products resemble concrete, so the minimum amount of the mixture is the same as in the previous case. The maximum allowable value can vary from 8 to 15 millimeters. It all depends on the curvature of the walls.
wooden surfaces
It is not so easy to attach the mixture to the tree. Therefore, before starting work, a metal or plastic mesh is installed on a wooden wall. The optimal cell size is not more than 40 millimeters. The metal mesh is attached to the surface with self-tapping screws, the plastic mesh is planted on glue. The solution is applied in two layers. The thickness of the first big role does not play. It is applied to hide the grid. The thickness of the second layer ranges from 1.5 to 2 centimeters.
Drywall
By itself, drywall is a good finishing material, so it rarely needs additional alignment. If it becomes necessary to apply plaster, the minimum layer is 1.5 mm, the maximum is 10. If the maximum amount of plaster is applied to the drywall, a plastic mesh must first be installed.
Heaters
As in the case of wooden surfaces, the insulation is plastered in two stages: the first one covers the reinforcing mesh - 1.5 centimeters, the second layer - leveling - 1-2 cm. These data apply to all types of insulation, including mineral wool and foam.
The working process
Plastering walls involves applying several layers. Each is applied for a specific purpose.
splatter
A preliminary layer that is applied to a bare wall. The purpose of spraying is to bond the wall surface with the plaster mix. For spraying it is necessary to use a liquid mixture. The plaster is simply thrown onto the surface of the wall, leaving as many irregularities as possible. For brick, concrete and aerated concrete blocks, the spray thickness is 5 millimeters, for wooden surfaces - 9 mm (including reinforcing mesh).
Priming
This is the main layer of plaster. The primer is applied after the spray has set a little. It is impossible to allow complete drying of the preliminary layer, this will complicate the adhesion of materials. For soil, a mixture of a thicker consistency is used. It is applied as follows: a small amount of plaster is thrown onto the wall and immediately leveled. The procedure is repeated until the entire wall is plastered. To optimize the process, you can install special beacons on the wall before spraying. These are metal or plastic guides that are leveled to the required thickness of the plaster layer. The distance between the beacons is 1-1.2 meters. The soil is thrown between the beacons and smoothed out.
If gypsum or lime mortar is used for the soil, the recommended thickness is about 7 millimeters. For cement mixtures, the optimum soil thickness is 5 mm.
Nakryvka
This is a finishing coat designed to eliminate small defects and inaccuracies. For coating, mixtures are used, the fraction of which does not exceed 2 millimeters. The final layer is applied with a wide spatula, but is not thrown onto the surface, as in previous cases, but is pressed tightly and smoothed with circular movements. The thickness should be minimal for all types of surfaces. After covering, the plastered walls are grouted.
There are cases when the solution is applied in one layer. The thickness of cement-based plaster should not exceed 2 cm, lime and gypsum mixtures - 1.5.
Tolerances
The thickness of the plaster on the wall is prescribed in building codes and regulations (SNiP), act 3. 04. 01-87. All norms for insulating and finishing coatings are indicated here.
- For simple plaster, the maximum allowable deviation in the vertical plane is not more than 3 millimeters. For high-quality mixtures, this figure should not exceed one millimeter.
- On the entire wall (in the vertical plane), no more than 15 millimeters are allowed for plastering with simple mixtures and 5 mm for high-quality materials.
- It should be noted that even the number of errors is strictly regulated. On a plot of 4 square meters, no more than three defects are allowed. And this is when working with a simple mixture. For high-quality requirements are even stricter, no more than two.
- The depth of the irregularities should not exceed 5 and 2 millimeters. For simple and high quality materials respectively.
- To perform work in a horizontal plane, the requirements are the same. Therefore, it makes no sense to repeat them.
- Remember that there are certain requirements for the humidity of the draft wall. This indicator should be within 8%. To determine the level of humidity, there is a special device - a moisture meter. If there is no device, you can simply inspect the wall. It should be dry visually and to the touch.
Conclusion
Plastering walls is not such a complicated procedure as it seems at first glance. The main thing is to properly prepare the base and monitor the thickness of the laid coating.Remember a few practical tips.
- If the solution is applied in several layers, the total thickness of which exceeds 3 centimeters, be sure to use reinforcement.
- Prepare your base carefully. An influx on the wall with a thickness of only 1.5 millimeters will increase the amount of material used by at least 3-4 bags.
- Use beacons to make your job as easy as possible.
