There are many varieties and brands of plasters in the modern market. And the most popular at the moment are mixtures of this type, made on the basis of gypsum. Of all the variety of such materials, the best reviews from consumers deserved the MP-75 plaster.
Who produces and what is it for
Engaged in the production of this material is well-known in Europe and Russia, the German company Knauf. Building mixtures from this manufacturer are of high quality and relatively low cost. In our country, they are simply very popular.
The gypsum mixture MP-75 is intended primarily for machine plastering of surfaces. It can be applied to walls using, for example, equipment such as PFT G4, PFT G5. Of course, it is allowed to use this plaster for manual wall decoration.
The mixture MP-75 can be used both for plastering walls and for puttying. Since this material is made on the basis of gypsum, it is allowed to use it only for decoration of walls and other structural elements indoors. However, in this case, unlike the same mixtures of many other brands, this plaster is allowed to be used even in conditions of high humidity.
Advantages and disadvantages
The main advantage of the plaster of this brand, experts consider its softness and elasticity. Applying this product on the surface, judging by the reviews available on the Web, is very convenient. Also, the advantage of this material is complete uniformity both in dry form and after solution preparation.
It can also be attributed to the advantages of this plaster that, according to the manufacturer, it is capable of "breathing". Accordingly, in those rooms where such decoration was used, a pleasant microclimate is established.
Of the shortcomings of this tool, it is possible to single out basically only a rather high cost. Also, a small minus of this material, many experts believe that it dries somewhat longer than gypsum plasters of other brands.
Structure
Of course, the exact proportional composition of the MP-75 plaster is the commercial secret of Knauf. However, it is known that, in addition to the gypsum binder, this mixture contains various kinds of polymer and other additives designed to improve its working and operational qualities - ductility, drying time, moisture resistance, etc.
Features of use
It is allowed to apply MP-75 plaster from Knauf on walls and ceilings from practically any material capable of supporting its weight. According to information from the manufacturer, it is possible to impose such solutions on the surface with a layer of 8 to 50 mm. The exception in this case are only the ceilings. On such surfaces, this plaster can be applied with a layer of not more than 15 mm.
Porous, moisture-absorbing materials - foam concrete, brick - before using this plaster, the manufacturer recommends pre-treatment with Knauf Grundirmittel primers or Rotband-primers. This procedure is necessary for uniform drying in the subsequent plaster mortar, as well as its better adhesion to the treated surface. Smooth materials - concrete, polystyrene foam, cement plaster - before applying the MP-75 mixture, it is recommended to primer the concrete contact from Knauf.
To apply MP-75 plaster it is allowed both with use of beacons, and without. To align the layer, it is recommended to apply the h-shaped rule. The manufacturer recommends plastering walls using this mixture in a well-ventilated area.
Also, when using this tool, it is necessary to comply with the following rules:
when mixing, water should be used with a temperature not exceeding +30 ° C, otherwise the performance of the finished plaster layer will deteriorate;
You can use MP-75 mixture for surface finishing only if it has been stored for no longer than 6 months. from the date of issue.
Main characteristics
One of the advantages of MP-75 plaster is its low consumption. From 1 kg of such a mixture, 1 l of working solution is ultimately obtained. Actually the very consumption of this product is 10 kg per 1 m 2 . Such an amount of material is needed for applying the finishing layer with a thickness of 10 mm.
Among other things, machine Knauf plaster MP-75 is also distinguished by the following characteristics:
bulk density - 850 kg / m 3 ;
drying of the plaster layer 15-20 mm - 7 days at a temperature of 20 ° C and a humidity of 60%;
compressive strength - 2.5 MPa, bending - 1 MPa;
granularity - up to 1.2 mm.
Rules for working with the machine
When applying MP-75 plaster on the walls, it is recommended to keep the gun perpendicular to the surface at a distance of about 30 cm from it. Apply the mortar when using the machine, starting from the upper left corner, from left to right and from top to bottom, with the formation of bookmarks with a width of about 70 cm. Each subsequent bookmark is supposed to be applied with an overlap of 5-10 cm to the previous one on the left side.
Special instructions for use
When using machine plaster MP-75 for wall decoration, among other things, it is worth following the manufacturer's recommendations:
Apply the mortar to the walls, ceiling or floor only after the primer has completely dried. In most cases, plastering begins at least 6 hours after surface treatment with such a composition.
Leave the solution in the hoses of the machine for longer than 15 minutes. not allowed.
Correction of a layer of mortar already existing on the wall, floor or ceiling in order to increase its thickness is allowed only when no more than 30 minutes have passed since its application. Otherwise, you should first wait for it to completely dry. Next, the first layer must be primed.
On the ceiling, MP-75 plaster should begin to be applied from the side opposite from the windows.
Plastering ceilings in more than 1 layer when using this tool is prohibited.
Ceramic tiles may only be glued to MP-75 plaster if the latter is applied to the surface with a layer of at least 10 mm. In this case, the finishing layer before installing the tiles is supposed to be treated with a deep penetration primer. In places of a possible direct hit on the water tile, it is also recommended to additionally use the Knauf-Flehendicht waterproofing.
During the first 3 hours after application, the MP-75 plaster coat is highly discouraged. This can adversely affect the quality of the finished finish.
The final stage: features
After about 90-120 minutes. After application, the MP-75 gypsum plaster must be leveled with a trapezoidal metal strip or trowel. Further, if the surface is prepared for painting or stickering the wallpaper, after about another 15 minutes, the surface of the finished wall should be:
In order to achieve a glossy surface, not earlier than 5 hours after plastering, the finishing layer must be moistened again and thoroughly smoothed with a metal grater. The wall thus treated can subsequently be painted without additional puttying.
On the ceiling, after smoothing down, the gypsum plaster MP-75 from Knauf should be cut along the perimeter of the room to the entire depth with the Stukzege saw. This procedure is supposed to be done until the finish is completely dry. Cutting is necessary in order to prevent subsequent cracks in the stucco layer on the ceiling.