Preparing the base:
The base must be dry and durable. Brickwork, concrete bases and mineral plasters must be cured for at least 28 days. Before applying the plaster-adhesive mixture, it is necessary to remove crumbling elements, oil stains, snow, ice, frost and other contaminants from the surface of the base that prevent the adhesion of the material to the surface. To pre-level the surface and eliminate significant unevenness, it is recommended to use appropriate leveling plaster. To enhance the adhesion strength of the material to the base, treat the surface with appropriate primer. The surface is ready to apply the material only after the soil has completely dried. When the work temperature is below +5°C, priming is not performed. In this case, the base must be thoroughly cleaned with a brush.
When performing work using extruded polystyrene foam, before gluing and before applying the base plaster layer, the surface of the slab must be roughened mechanically.
When subsequently installing a reinforced base plaster layer, the surface thermal insulation boards Clean thoroughly with a brush to remove dust.
Preparation of the solution:
Before use, the dry mixture must be kept at a temperature above 0°C for at least 24 hours. Also, before starting work, all elements of the insulation system must be kept at positive temperatures. To prepare the solution, it is recommended to use water at a temperature of +10 to +30°C. Pour the contents of the bag into a container with constant stirring. clean water based on 1 kg of dry mixture 0.18-0.22 l clean water(for 1 bag of 25 kg - 4.5-5.5 liters of water) and mix until a homogeneous mass is formed. Mixing is done mechanized (professional mixer) or manually. The solution must be kept for 3-5 minutes, then mixed again. After this, the solution is ready for use.
The solution can be used within 1 hour from the moment of mixing with water. When the viscosity of the solution in the container increases (within the pot life time), it is necessary to mix it thoroughly without adding water.
To prepare the solution, use only clean containers, tools and water.
Execution of work:
Fastening of thermal insulation boards:
The adhesive solution can be applied to the surface of the insulation different ways. If the base is uneven with a depth of more than 3 mm, the adhesive solution is applied to the surface of the insulation using a trowel along the perimeter of the slab in a continuous strip, as well as dotted in the center. The width of the continuous strip is 3-4 cm, the thickness of the adhesive layer is about 20 mm. If the base is uneven less than 3 mm, the adhesive solution is applied using a notched trowel or trowel evenly over the entire surface of the slab.
Immediately after applying the adhesive solution, the plate is applied to the surface and pressed tightly. The plate adjustment time is 15 minutes. The insulation boards are attached in one plane, with T-shaped dressing of the seams, close to one another. The gap between the plates is no more than 2-3 mm. Subsequent work on installing dowels and constructing the base layer can be done no earlier than after 2-3 days.
Construction of a reinforced base plaster layer:
Using a notched trowel or trowel, the plaster-adhesive solution is applied in a thin layer to the surface of the slab and distributed evenly. Reinforcing facade fiberglass mesh (with an overlap of at least 10 cm) is laid on a freshly applied plaster layer, “sinked” into it and smoothed so that the mesh is in the middle of the base layer.
During operation and in the next two days the temperature environment and the base should not be lower than -10ºС. At temperatures below -10 ºС, all work should be carried out in a thermal circuit. During the hardening process, the surface must be protected from intense drying: avoid exposure to direct sunlight, water and drafts. Application of decorative plasters, paint and varnish materials and finishing with other decorative coatings are carried out no earlier than 7 days after the creation of the reinforced base layer.
KNAUF Sevener- dry mixture on lime- cement based for outdoor and interior work. Contains special fibers and polymer additives that provide the finished solution layer with high adhesion, crack resistance and water-repellent properties. A special combination of binders with adhesive additives and fiber provides sufficient adhesion and gives the plaster layer increased strength and significantly higher crack resistance compared to already known solutions. The water-repellent additive protects the insulation and masonry from getting wet and, due to the low resistance to water vapor diffusion, does not worsen the residential microclimate. Knauf Sevener is used in the construction of systems external thermal insulation buildings for gluing thermal insulation boards made of polystyrene foam or mineral wool and applying a protective layer reinforced with fiberglass mesh to their surface, followed by coating with decorative plasters Diamant-240 and 260, etc. Knauf Sevener can be applied to structured, durable, dust-free mineral plasters and the same surfaces with dispersion coatings or plastering coatings based on artificial resins (if necessary after appropriate treatment).
Knauf Sevener can be used:
For repairing old (cracked) plaster surfaces of building facades;
- as a mortar under reinforcing mesh on hardened plaster when laying with mixed building materials;
- as an adhesive bridge plaster for surfaces of smooth and porous concrete, etc.;
- as a thin-layer intermediate layer of plaster for smooth concrete surfaces.
Knauf Sevener is applied manually and mechanically, for example, using continuously operating high-performance mortar-mixing pumps, for example "G4", "G5", "Monojet" from PFT.
Consumption of materials
Depending on the type of work, the consumption of dry mixture per 1 m2 is:
Cladding a flat surface with insulating boards old plaster~ 3.5 kg
Cladding with masonry insulating boards ~ 6 kg
Applying a protective layer to the surface of insulating boards ~ 7 kg
Plastering a layer of old plaster over a grid ~ 5 kg
Preparing the base
Conditions of work
The temperature of the surface of the base and the air in the room should not be lower than +5°C.
Preparation of the base surface
Clean concrete, masonry or old plaster from dust.
- Check the old plaster for strength and adhesion to the base.
- Clean out potholes and pre-plaster them.
- Strengthen chalking and crumbling surfaces with KNAUF-Tiefengrund primer.
Preparation of the solution
Mix the contents of a Knauf Sevene bag (30 kg) with 6.0 liters of water manually or using a drill with a mixing attachment. Leave for 15 minutes and stir again. Adding any materials is not allowed. When working with plastering machines, for example, from the PFT company, set the water dosage to about 320 liters and adjust the consistency of the solution.
Application of Knauf Sevener
Cladding with insulating boards
Apply Knauf Sevener mortar around the perimeter, as well as in the middle of the insulating board, in dots or in a continuous zigzag stripe. Bandwidth - approx. 5 cm, thickness - about 2 cm. Place the insulation board on the wall and level it. Further work with the slabs should be carried out after the solution has hardened (~ 48 hours).
Reinforcement of the surface of insulating boards
Apply KNAUF-Sevener mortar 5 mm thick and level with the rule. Install protective corners on the outer corners. Diagonally, at the corners of all openings, reinforce the surface of the insulating boards with strips of reinforcing fiberglass mesh measuring ~30x50 cm. Place reinforcing mesh in fresh mortar over the entire surface with an overlap of approx. 10 cm, while the solution should cover the mesh. If necessary, dowels are installed for additional fastening slabs Before continuing work, allow the reinforcing layer to harden and dry for 8 days.
Repair solution
To level out structural irregularities, apply KNAUF-Sevener to cleaned or prepared surfaces of old plaster in a layer of up to 10 mm. If necessary, lay reinforcing mesh.
Thin-layer plaster on concrete
Apply KNAUF-Sevener with a thickness of 3.5 mm to a concrete surface cleaned of dust and smooth it. During the setting of the solution, when a certain surface hardness is reached, remove the formed sagging.
Plaster-bridge
On a smooth surface of concrete, aerated concrete, etc. Apply an intermediate connecting plaster layer of KNAUF-Sevener up to 10 mm thick, smooth it and, no less than 3 days later, apply the KNAUF-LUP-222 solution.
Plastering on mesh
Apply Knauf-Sevener to the dry layer of plaster over the entire surface in a layer of ~ 3 mm. Lay strips of reinforcing mesh measuring ~30x50 cm diagonally relative to the corners of all openings. Lay reinforcing fiberglass mesh over the entire surface with an overlap of 10 cm. The next day, once again apply a layer of Knauf-Sevener mixture ~2.3 mm thick. After the solution has set, rub the surface with a felt float. To produce paintable surfaces in an external insulation system, it is necessary to re-apply the KNAUF-Sevener solution and lay a fiberglass mesh in it with the joints offset relative to the first layer. After acquiring the required hardness, apply another Knauf-Sevener solution with a thickness of ~ 2.3 mm to this layer and, upon reaching the appropriate hardness, treat with a felt or sponge trowel. Upon completion of work, tools must be immediately washed with water.
Protect fresh plaster from frost and quick drying. Application decorative covering carry out only after the KNAUF-Sevener solution has hardened and dried. Before applying decorative plasters KNAUF Diamant-240 and 260, coat the KNAUF-Sevener surface with KNAUF-Izogrund primer.
Packaging and storage Knauf Sevener
KNAUF-Sevener is packaged in 30 kg paper bags.
Store bags with plaster mixture in dry rooms on wooden pallets. Pour the material from damaged bags into intact ones and use them first.
Shelf life in undamaged packaging is 6 months.
Reinforced, crack-resistant plaster-adhesive mixture for gluing thermal insulation boards and creating a reinforcing layer.
Application area:
A specialized dry mixture based on cement binder, mineral and polymer additives for the installation of insulation boards on any non-deformable base, as well as for the installation of a reinforcing layer using alkali-resistant mesh with a density of at least 145 g/m
Modifications (see article)
Preparing the base:
The surface must be dry, durable, thoroughly dust-free, free of dirt, oil and bitumen stains, and other contaminants that could prevent
Adhesion of the material to the surface.
Preparation of the solution:
The mixture is poured into a container with clean water (at the rate of 5.0–6.0 liters of water per 25 kg of mixture) and mixed mechanically until a homogeneous mass is obtained (about 5 minutes). The solution is kept for 3 minutes, after which it is mixed again for 2 minutes.
Application:
Installation of insulation boards is carried out from the bottom up. The adhesive mixture is applied along the perimeter of the insulation board in a strip 3-4 cm wide, 5 cm away from the edge of the board, and several cakes with a diameter of 8-10 cm in the middle. The number of cakes applied depends on the size of the slab.
The slab with the glue applied should be immediately applied to the base and pressed so that it is in the same plane as the adjacent slabs. After pressing the insulation board, the adhesive mixture should cover at least 60% of its area.
Mechanical fastening of the insulation using dowels is carried out 24 hours after gluing the slabs.
The reinforced layer is applied no earlier than 24 hours after gluing the slab.
The work is carried out “from top to bottom.” Using a metal trowel or spatula, a layer of adhesive mixture 3 mm thick is applied to the entire surface of the insulation, and leveled with a notched trowel, then the reinforcing mesh is embedded. In this case, it is necessary to ensure uniform stretching of the mesh, avoiding the appearance of bubbles and folds. After this, a second, leveling layer of the adhesive mixture with a thickness of 1-2 mm is immediately applied.
Thin-layer decorative plaster coatings or alkali-resistant paints are applied 3 days after installing the reinforced layer.
Consumption: depends on the installation method and the thickness of the reinforcement layer, on average 1.6-1.8 kg/m 2 mm.
Packaging and storage:
Kraft paper bags of 25 kg. The shelf life in a dry place and original packaging is 12 months from the production date indicated on the packaging.
Security measures:
Do not let the dry mixture get into your eyes. In case of contact, rinse the affected area thoroughly. running water, if necessary, consult a doctor. Wear goggles and protective clothing when working.
Application area
Dry cement-based mixture for external and internal work. Contains fractionated sand, special fibers and polymer additives that provide the finished mortar layer with high adhesion, crack resistance and water-repellent properties. The water-repellent additive protects the insulation and masonry from getting wet and, due to the low resistance to water vapor diffusion, does not worsen the residential microclimate. It is used in the construction of external thermal insulation systems for buildings for gluing thermal insulating slabs made of polystyrene foam or mineral wool onto ordinary bases and applying a protective layer reinforced with fiberglass mesh to their surface, followed by coating with decorative plasters KNAUF-Diamant 260, etc.
KNAUF-Sevener can be applied to structured, durable, dust-free mineral plasters and the same surfaces with dispersion coatings or plaster coatings based on artificial resins. (if necessary after appropriate processing). Can be used:
for repairing old (cracked) plaster surfaces of building facades, including structural plasters, without or with a durable paint coating;
as a mortar under reinforcing mesh on hardened plaster when laying with mixed building materials;
as an adhesive bridge plaster for surfaces of smooth and porous concrete, etc.; as a thin-layer intermediate layer of plaster for smooth concrete surfaces. Can be applied manually and using PFT G5, PFT G4, PFT Monojet plastering machines.
The product is manufactured with constant internal and independent (GOST R certification) control.
Package
The KNAUF-Sevener mixture is packaged in 25 kg paper bags.
Storage
Store bags of KNAUF-Sevener dry mixture in dry rooms on wooden pallets. Empty the material from the damaged bags and use it first.
Shelf life in undamaged packaging is 12 months.
Consumption of materials
Depending on the type of work, the consumption of dry mixture per 1 m2 is:
Preparing the base
Conditions of work
The temperature of the base and ambient air should not be lower than +5°C.
Preparation of the base surface
Clean concrete, masonry or old plaster from dust, if necessary, wash with water under pressure. Check the old plaster for strength and adhesion to the base. Clean out potholes and pre-plaster them. The surfaces of leveling plasters must be dry before applying the KNAUF-Sevener mortar mixture. Strengthen chalking and crumbling surfaces with KNAUF-Tiefengrund primer.
Preparation of mortar mixture
Mix the contents of the bag (25 kg) with 5.0 liters of water manually or using a drill with a mixing attachment. Leave for 15 minutes and stir again. Adding any materials is not allowed! When working with plastering machines, for example, from PFT, set the water dosage to about 320 liters and adjust the consistency of the mortar mixture, increasing or decreasing the water supply.
Protect fresh plaster from frost and rapid drying.
The decorative coating should be applied only after the KNAUF-Sevener solution has hardened and dried.
Before application decorative plaster KNAUF-Diamant 260 coat the surface of KNAUF-Sevener with KNAUF-Izogrund primer.
Application
Facing with insulating boards Apply KNAUF-Sevener mortar around the perimeter, as well as in the middle of the insulating board, in dots or in a continuous zigzag stripe. Bandwidth - approx. 5 cm, thickness - about 2 cm. Place the insulation board on the wall and level it. Further work with the slabs should be carried out after the solution has hardened (after 48 hours).
Reinforcement of the surface of insulating boards:
Apply the KNAUF-Sevener mortar mixture 5 mm thick and level it as usual. Install protective corners on the outer corners. Diagonally, at the corners of all openings, reinforce the surface of the insulating slabs with strips of reinforcing fiberglass mesh measuring 30x50 cm. Place the reinforcing mesh over the entire surface in a fresh mortar mixture with an overlap of approx. 10 cm. If necessary, dowels are installed for additional fastening of the slabs. Before continuing work, allow the reinforcing layer to harden and dry for 8 days. Repair solution
To level out structural irregularities, apply KNAUF-Sevener to cleaned or prepared surfaces of old plaster in a layer of up to 10 mm. If necessary, lay reinforcing mesh.
Thin-layer plaster on concrete: Apply KNAUF-Sevener with a thickness of 3-5 mm to a dust-free concrete surface and smooth it. During the setting of the mortar mixture, when a certain surface hardness is reached, remove the formed sagging. Plaster-bridge
On a smooth surface of concrete, aerated concrete, etc. Apply an intermediate connecting plaster layer of KNAUF-Sevener up to 10 mm thick, smooth it over and apply KNAUF-LUP 222 solution no less than 3 days later.
Reinforcing the surface of plasters Apply KNAUF-Sevener to a dry layer of plaster over the entire surface with a layer of 3 mm. Lay strips of reinforcing mesh measuring 30x50 cm diagonally relative to the corners of all openings. Lay reinforcing fiberglass mesh over the entire surface with an overlap of 10 cm. The next day, once again apply a layer of Knauf-Sevener mixture 2-3 mm thick. After the solution has set, rub the surface with a felt float. Additional reinforcement In the case of manufacturing rubbed surfaces for painting in an external insulation system, it is necessary to re-apply KNAUF-Sevener and lay a fiberglass mesh in it with the joints offset relative to the first layer. After acquiring the required hardness, apply Knauf-Sevener again with a thickness of 2-3 mm to this layer and, upon reaching the appropriate hardness, treat with a felt or sponge trowel.
Upon completion of work, tools must be immediately washed with water.
Mechanisms
Plastering machines PFT G5,
PFT G4, PFT Monojet.
Screw pair D4-3.
Rotoquirl mixer.
Equipment and tools
Plaster mixer (N > 800 W)
Plastic tank
Stainless steel trowel
Sokol plastering
Rule (h-profile) aluminum
Felt or sponge grater
Toothed metal spatula
Metal lattice grater (Rabbo)
Knauf is rightfully considered the most famous manufacturer plaster mixtures in our market. Numerous types of products from this company provide solutions to almost any internal and external plaster. And today we want to talk about one of these products - Knauf-Sevener, a plaster-adhesive mixture that is becoming increasingly in demand in domestic market. At the same time, we will analyze the advantages and disadvantages of the material, list the areas of its use, consumption per 1 m2, as well as application technique.
Products from Knauf under the Sevener brand belong to the category of cement plaster mixtures. This means that it is ideal for external works, since the stability of the composition is much higher than that of gypsum options. It is sold in dry form, which must be diluted with water before use according to the manufacturer's instructions. The most popular packaging form factor is 25 kg.
In addition to cement, the plaster contains sand, special fibrous components and additives that improve performance characteristics material, such as moisture resistance.
For what purposes is this finishing material used?
- Finishing of facades and plinths of buildings, as well as repair of previously plastered surfaces as part of external work. The composition fits perfectly on concrete and brick surfaces;
- Bridge plaster, which improves the adhesion of smooth and porous concrete layers;
- Plaster over insulation. To do this, the first layer is applied directly to the material, in which the reinforcing mesh is embedded, after which everything is covered with a second layer, resulting in a durable coating;
- As an adhesive mixture for insulating buildings with polystyrene boards or mineral wool.
Important! The composition is equally suitable for both manual application and machine work.
Specifications
- Density after drying - 1600 kilograms per cubic meter;
- The maximum size of sand fractions is 1.5 millimeters;
- Compressive strength – 7.5 MPa;
- Frost resistance – 75 cycles of freezing and thawing;
- Vapor permeability coefficient – 0.1 mg/(m h Pa).
Benefits of plaster
- Even after prolonged use, with proper initial preparation of the composition, cracks do not appear on the surface of the plaster;
- The plaster tolerates moisture well. For this, as in the case of cracks, the fibers that make up the material are responsible, making it not only plastic, but also moisture resistant;
- Strength cement plaster much higher than that of gypsum analogues;
- The cost of cement-based plaster is also lower than that of gypsum. That is why the latter is mainly used for interior work, and the former for external facade decoration;
- The material has full vapor permeability, which allows it to maintain an optimal microclimate in the room;
- Good resistance to temperature changes. Plaster can withstand a large number of freezing and thawing cycles.
Flaws
As for the disadvantages, this plaster simply does not have any within the scope of its work. In addition, we are talking about the manufacturer Knauf, the quality of whose mixtures is at the highest high level. The only disadvantages that can be cited are that such “wet” facade works more labor-intensive than cladding a building, and, moreover, can not be carried out on all types of walls. But this applies to general shortcomings, and not specifically to this product.
Material consumption
The key to the efficiency of Sevener plaster lies in its low consumption. For 1 m2 of wall surface, depending on the type of wall surface and the form of finishing, it takes about 3.5-7 kilograms. Thus, a maximum bag of 25 kg is enough for finishing 7 square meters wall surface. And since a bag costs only 465 rubles, even large-scale facade work will be affordable for most. In general, the material consumption depending on the work is as follows:
- The adhesive composition when cladding the facade with insulation slabs on a flat wall surface is 3.5 kilograms per square meter;
- Similar work, but in the case of masonry - 6 kilograms per square meter;
- Work on top insulating material– up to 7 kilograms per square meter;
- When working on top of the old structural plaster– 5-10 kilograms;
- Similar to the top one, but using alkali-resistant facade fiberglass mesh - 5 kilograms.
Features of work
In general, all the requirements for applying such plaster are similar to those that apply to other similar cement-based mixtures. Therefore, it is necessary to start with careful preparation of the working surface. The wall must be thoroughly cleaned of unstable fragments, dirt and anything that can reduce adhesion. In this case, it is best to remove the old finishing coating, if we are not talking about work during the construction of the building.
Important! Work on applying the mixture must be carried out at temperatures from +5 to +30 degrees Celsius in dry weather. In extreme heat, the material already applied to the walls begins to dry unevenly, but when low temperatures the composition does not gain its properties.
At the next stage, the solution is mixed, for which water is gradually added to the powder mixture. A 25 kilogram bag uses approximately 5 liters of water. It should be noted here that the viability of the ready-to-use solution is 2 hours. After this, the composition hardens and begins to lose its performance qualities. So knead only as much as you can use during this period. At the same time, it is much more effective to mix the solution during dilution not by hand, but by using a drill with a special attachment.
The mixture is applied both manually and using automatic means - high-performance mortar-mixing pumps. If the walls are too smooth, the adhesion of the compound may not be sufficient and it will not bond to the surface properly. In this regard, you can apply notches to the wall, thus increasing the roughness, or proceed as follows:
- Treat the surface hydrochloric acid, which is mixed with water in proportions of 1 to 6. In this case, the wall is covered with the solution and left for some time until the surface is corroded and becomes rougher;
- Wiping the wall with a solution of cement and coarse sand, mixed in proportions of 1 to 1.5;
- Wetting the surface with water before finishing. But here you need to be careful not to overdo it, since if there is too much moisture, the plaster will simply slide off the wall.