Gypsum plaster rotband instructions for use

What is a rotband

One of the oldest manufacturers of gypsum powders for the construction industry in Europe, the Knauf company, mastered the production of dry mixes (SS) intended for plastering walls in the last century.

In addition to gypsum, the mixture contains modifying additives, thanks to which the solution not only becomes more plastic, but also does not set longer and adheres more reliably to the base.

Practical Germans began to depict a red ribbon on the packaging of new products as a symbol of the brand. The SS itself was named accordingly - RotBand (red ribbon translated from German).

Gypsum plaster marked rotband is a universal material. Suitable for many types of substrates, not only for dry rooms or indoor conditions, but also for leveling walls in rooms with temporarily increased humidity.

In the latter case, it is necessary to use a coating that protects the plaster from moisture. You can level the wall with a rotband on a glazed loggia or veranda, since the coating can withstand 75 freezing cycles without loss of strength.

Possessing high adhesion, Knauf Rotband is especially suitable for manual application on dense concrete and ceiling surfaces, with which other compounds do not work well. The tenacity and strength of the composition allows the mixture to be applied to vertical surfaces in one layer up to 50 mm thick.

The plaster mass is easy to prepare and apply even to hard-to-reach areas, since the material is highly plastic. This increases the productivity of plasterers and reduces fatigue.

Other advantages include:

• ease of processing;
• non-flammability;
• the ability of the created coating to maintain a microclimate;
• the ability to achieve a smooth surface suitable for painting by simple processing.

In order for the coating to be durable and last a long time, plastering the walls with rotband should be carried out in accordance with the guidelines developed by the company’s specialists. Instructions are located on the packaging.

How to apply a plaster layer with your own hands?

Let's look at how to properly plaster walls. The finishing material has another excellent quality. A novice master can learn to work with gypsum plaster, and he does not need to develop a special skill over several years.

There are two methods of working with Rotband:

• plaster on beacons;
• plaster without beacons.

Let's consider each type of work separately.

By lighthouses

Any master will tell you: correct drawing of the wall geometry can only be done using beacons. And this rule works in most rough work. Especially where the surface has large differences or a special build-up of a thick layer of plaster is required. The algorithm for working with beacons looks like this:

1. The prepared primed base is carefully measured with a building level. This can be either a bubble or a laser tool. The latter is preferable to use, as it gives a complete picture of the geometry of the walls and has higher accuracy.
2. On the extreme right and left sides of the wall, marks are placed on the floor and ceiling.
3. Based on the marks received, two starting beacons are set. They will define the geometry of the entire surface. Lighthouses are secured to the wall with the same Rotband.
4. Two horizontal threads or twines are pulled through the starting guides with a slight tension. It is necessary that the thread does not dangle, but also does not pull the beacons.
5. The remaining beacons are placed along the resulting guides, then the threads are removed.
6. Throw the prepared Rotband so that it extends beyond the beacons by 5–15 mm.
7. The scattered mixture is leveled with a rule of up to 1.5 meters. Excess mortar is removed from the rule using a 1–15 cm trowel.
8. The extreme corners are finished at the last moment.
9. After the mixture has dried, the beacons are removed, and the resulting grooves are carefully sealed with the same mixture using a rule.

Prepare a clean instrument. The rule and the trowel must be cleaned of old, dried building materials; there should be no dirt on them.

Without beacons

Another way is to work without beacons. It is suitable for finishing walls or for cosmetic repairs. You can work without beacons if the differences do not exceed 3–4 cm.

The algorithm for working without beacons will be like this:

1. Prepare the working surface, clean and prime it.
2. It is advisable to check it with a level or a long, even stick to find out in which corners or places of the base the differences are maximum.
3. Mark problem areas of the base with a pencil or marker.
4. Prepare a clean rule at least 1.5 meters long and a trowel up to 10 cm.
5. Mix a small amount of solution. Seal all seams, cracks and potholes. Let it dry.
6. Prepare the remaining solution.
7. Apply the mixture onto the wall in even strokes. It is important that the solution adheres well to the base, so it is best to throw it on the wall.
8. Gently stretch the mixture over the entire surface. Remove excess with a trowel.

Advice

Do not prepare a large amount of solution at once. The finished mixture is plastic up to 30–40 minutes. After this time, it becomes tough and difficult to work with. It is better to dilute the solution to a wall area of ​​up to 5 square meters. m.

Rotband: step-by-step instructions for use for beginners

The instructions for use suggest that the sequence of plastering a room when Rotband plaster is used is similar to the procedure for working with other plaster compositions.

The order of work during plastering of the entire room:

• ceiling plaster;
• processing and leveling of walls;
• finishing of slopes, columns.

Next, we will consider in detail each stage of plastering with rotband.

Preparing the base

Regardless of the newness of the walls, before plastering the surface of the base is prepared, since conditions must be created for a strong connection of the two materials. The second purpose of preparation is to cleanse stains of a biological nature - to protect the plaster coating from the appearance of mold, rot or fungus in the future. And removing rust prevents brown spots from bleeding through the layers of finish.

Another task of the preparatory stage is to strengthen the weak near-surface layer and repair defects. In addition, if the base has a porous structure, then the open pores during plastering will take away the water needed by the solution, disrupting the hardening processes of the plaster. Therefore, the pores need to be clogged before starting work.

Before work, you should de-energize the wiring and protect sockets, windows and doors from damage.

In the room being renovated, plaster, wallpaper, paint, peeling, unusable old plaster are removed from the walls. The resulting cracks and deep potholes are repaired. Remove old metal fasteners (nails, screws, hooks) from the walls.

If hardware needs to be left, they should be insulated (for example, painted) to prevent rusting. Stains of efflorescence, formed rust, grease, soot or any biotic growth are removed.

In a new building, preparation is also necessary. In brickwork, the seams are deepened to a centimeter and unstitched. The surface of the brick is scratched with steel brushes. Traces of grease are removed from the concrete, and notches are applied to smooth walls. Nodules and large protrusions are cut down. At the joints of plasterboard sheets, chamfers are cut off and screw heads are recessed. Before plastering, they are covered, for which a serpyanka is applied to the joints.

Primer

Before priming, be sure to remove dust from the surface and dry the base. The correct choice of primer for Rotband Knauf determines the result of all subsequent work.

The instructions indicate the brands of primers used for different substrates:

• easily absorbing water (cellular or expanded clay concrete, cement-lime plasters, brickwork) - primed with Tiefengrun or Mittelgrunt (dries in 6 hours);
• Dense materials that do not absorb moisture (concrete, polystyrene foam, cement plasters, tongue-and-groove slabs) are treated with Betonkontakt and dried for 12 hours.

Mittelgrunt (can be replaced with Knauf-Multigrunt, dilution proportions are given in the primer manual).

Displaying beacons and corners

To level the surface of a wall that has only slight deviations, you can do without beacons. When walls are littered or have a surface with large differences, beacons are used to create landmarks.

Before using them, ceiling and wall surfaces are weighed, the most protruding points are found, and the location of the auxiliary plane is determined. A mark (plaster) with a thickness of at least 5 mm is made on the site with a solution. They navigate by it by installing the slats. There is a detailed article about installing beacons on our website.

In addition to beacons, profile corners are mounted on protruding corners, aligned in the same plane with the beacon strips of adjacent walls.

Preparation of the solution

The instructions for use provide scant information about how rotband plaster is prepared for use. There are only four lines that may not be entirely clear to beginners. Therefore, we describe the process sequentially.

To dilute one (30 kg) package, you need to prepare a clean (without remnants of the previous batch, which is important) plastic container and pour 17 liters of water into it. So, out of the 18 liters specified in the instructions, there remains a liter of water, which will be needed if the resulting solution is too thick.

In the latter case, at the end of mixing, the density is adjusted by adding liquid. The capacity of the vessel depends on the number of plasterers involved in applying and leveling the mixture on the wall. If plastering is done alone, then a 90-liter container is enough to have time to work out the entire mass before setting begins (there are only 20-25 minutes left from the end of mixing).

The temperature of the air, as well as the base, is not lower than +5°C, not higher than +30°C.

Open the bag, scoop out the powder with a dry trowel, pour 8-10 portions into water, and begin to knead the mixture with a mixer.

Mixing a small amount of powder creates a solution, which will take a couple of minutes. During this time, additive substances pass into the water, facilitating the correct flow of the subsequent chemical process.

After this, the rest of the material in the bag is gradually poured in. This is done while continuing to stir, after which the solution is left, allowing 5-7 minutes to soak. Mix thoroughly and add water if necessary. If the solution mass comes out a little liquid, add dry powder from another package. Naturally, stored water is not added to such a mixture. After the second mixing, the mass is used for plastering, and SS can no longer be added to it.

Mixing is performed at low mixer speeds.

Tightening and leveling

The solution is applied in the same way as cement compositions. Use a spatula with a wide spatula or a wide grater. The mixture is used to fill the space from lighthouse to lighthouse. Having filled an area about a meter long, the solution is leveled along the beacons using a rule with an h-shaped profile.

If the thickness of the leveling coating is more than 15 mm, the plaster is applied in two layers. At the same time, having applied the first mark, it is “combed”, covering the surface with combs (for which a spatula with a comb is used). A day later (not earlier), when the applied mass has hardened, apply the next layer, which is leveled along the beacons.

The instructions warn that applying a second layer over a freshly laid one is only possible if another half hour has not passed since the start of its application. If they do not have time to meet this period, the layer is allowed to harden for a day.

To align, the tool bar is usually guided, leaning on the edges of the beacons, with small zigzags across the longitudinal line. The solution that accumulates on the rule is removed with a spatula, transferring it to unfilled areas. The rule is to do it one or two more times. After which they continue to fill the space between the beacons.

The slopes are plastered, maintaining the “dawn angle”. The correct plastering sequence is: the top one is plastered first, followed by the sides. For leveling, you can use a cut (short) rule, a wide spatula, or a specially made tool.

After approximately 45-60 minutes from the mixing time, the condition of the applied solution is checked by pressing it with a finger. If the set dough does not stick to your fingers, cut off the protrusions using a trapezoidal rule (the same can be done with a wide spatula). On slopes this is done with a “kantenhobel” (plane).

The result is a finish that has small (up to 3 mm) unevenness in the form of tool marks, scratches or burrs, as well as sagging up to 2 mm. A rough finish of this quality is suitable for decorative plaster (with a filler fraction of more than 2 mm), as well as gluing tiles.

Second contraction and alignment

If you need a better quality surface, wait 15-20 minutes after the first trim and perform a second trim. To eliminate unevenness, use a wide spatula.

Removing beacons and sealing grooves

The procedure for removing beacon profiles is carried out after the mortar mass has set and pulling out the metal parts will not cause the mortar to slide. Remove the planks by clearing the area near the end with a chisel. The edge of the lighthouse is clamped with pliers and pulled away from the wall.

After removing the profile, a groove is formed on the wall - a groove. Dust is removed from it, the inner surface of the groove and adjacent areas are primed. Then fill it with mortar, which is leveled flush with the wall with a wide spatula.

Grouting plaster

A special quality of smoothness can be achieved by grouting rotband plaster, performed 15-20 minutes after the second trimming. The plaster coating is moistened generously using a sponge grater (you can use a felt trowel).

Moving the grater in a circular manner, smooth out the marks left by the spatula or rule. Allow moisture to be drawn into the solution (this can be seen by the wall becoming dull), then smooth it with a spatula. This achieves a finishing quality suitable for gluing structural wallpaper, applying texture paint or decorative plastering with finely graded compounds.

If after another 2.5 hours (or within 24 hours) we wet the wall again with a sponge, we will pull out the gypsum milk from the surface layer. It will fill the remaining pores under the influence of the smoothing iron. This creates the basis for painting the wall with matte paints, making the Venetian.

Create a structure (if necessary)

Fine-grained gypsum plaster rotband is suitable as a material for creating relief patterns on the wall. You can create a unique decoration with your own hands, since the gypsum composition is harmless to the skin. You can experiment with gypsum plaster to achieve different effects. Wanting to change the interior design, they use shaping techniques, a description of which can be found in the Decorative plasters section.

To create a pattern after leveling the mass, a relief roller or any other forming tool (hard brush, trowel, brush, crumpled plastic bag, shaped spatula) is usually used. When the mixture has hardened and completely dried, the decorated ceiling is painted.

Features of ceiling plaster with rotband

There are some differences between finishing the ceiling and leveling the walls with a do-it-yourself rotband:

1. If a layer of up to 50 mm can be applied to the wall with a rotband, then a layer of up to 15 mm can be applied to the ceiling. Therefore, if the height difference on the ceiling is more than 30 mm, it makes no sense to plaster it to level it. You need to use other means, for example, drywall.
2. If during leveling the walls the movement of the tool when applying the plaster mass is directed from bottom to top, then when plastering the ceiling it is directed towards itself.
3. After plastering and smoothing, the gypsum thickness along the perimeter of the ceiling (without gaps) is cut to the base with a Stukzege saw. The use of such a constructive technique prevents the formation and development of shrinkage cracks, which otherwise can originate near the walls, developing towards the center of the ceiling.

Which ones to use

The choice of mesh will depend on where the plastering is carried out - indoors or outdoors, on the type of base, and the thickness of the applied layer of mortar.

Necessary tool

Before work, prepare the necessary tools:

• h-shaped and trapezoidal rule;
• wide spatula;
• corner spatulas;
• trowel;
• level and other devices for installing beacons;
• mixer;
• half;
• ironing board;
• rollers (for priming and applying patterns);
• brushes;
• sponge or felt grater;
• capacity (90/200 l);
• masking tape;
• cord, plumb line;
• clean rags.

A special feature of the tools used to work with gypsum mass is that the metal spatulas and trowels must be stainless. If you use tools made of rusting steel, black marks will remain on the wall.

How long does it take for the solution to dry?

The drying time for rotband plaster is indicated in the instructions for use for optimal conditions:

• humidity up to 60%;
• temperature – +20°C;
• layer thickness – 15-20mm.

It is 7 days. In fact, plastered walls may have a thicker or thinner coating, and the temperature conditions of the room may differ. With good ventilation, the drying time may be a couple of days shorter.

The manufacturer recommends priming the surface of the rotband after drying with Tiefengrund primer, the film of which will protect the gypsum material from moisture and increase adhesion to water-dispersed paint or wallpaper.

If the Knauf plaster that you used to renovate your apartment is already familiar, then when building a house there is a high probability of using this material again. We hope that the article “Rotband plaster: instructions for use” will help beginners achieve “German quality” guaranteed by the manufacturer.

What kind of mesh is needed for plastering walls?

The surface of enclosing structures, even with their impeccable construction, needs leveling, the classic of which is plastering. The plaster coating is often reinforced with a mesh of various materials of a certain mesh size. This additional step complicates and increases the cost of the process, but under certain circumstances it cannot be avoided.

Let's consider the role of reinforcement in a plaster coating, and which reinforcing mesh to give preference in a particular case.