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Plastering a wall yourself: instructions for inside and outside

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Plastering is one of the more demanding jobs for DIY enthusiasts. But it is quite feasible, both in new buildings and when renovating. We explain step by step how do-it-yourselfers can save money when building or renovating.

If you do the interior work yourself in your new house or if you renovate an old building, you may have to plaster the interior walls. No trivial work - it takes a lot of time and in the end everything has to fit. - Anyone who has worked crookedly and crookedly here can hardly cover up these mistakes with a new coat of paint or wallpaper. Nevertheless, skilled do-it-yourselfers can plaster their walls themselves. There are tools for this that make the work a little easier.

Plastering the inner wall: material and tools

material

  • Plaster profiles and corner rails.
  • Painter fleece and, if necessary, milk carton paper to cover it.
  • Plaster of your choice, amount depending on requirements and packaging information.
  • primer
  • Filler
  • Depending on the project, reinforcement fabric or fabric tapes, adhesive tapes for masking.

Tool

  • Leveling bar. Can also be a straight wooden slat.
  • Trowel, lattice rabot, float
  • Various buckets, especially larger buckets, to mix plaster in.
  • Drill with whisk attachment
  • Craft knife
  • Long pile rollers in different sizes for roll plaster.
  • Painter's brush

Plastering the inner wall: step by step

There are different methods and techniques for plastering a wall, but the basics are always the same. This video shows a classic technique, but it requires some practice.

Beginners find it easier with plaster rails. This makes the preparation more time-consuming, the costs a little higher and where the rails are in the plaster you can neither drill nor nail later. But the rails help to apply the plaster evenly and, above all, evenly. We explain this type of plastering in the following steps.

1. Determine material requirements

First measure the room. It's very easy: Determine the length and height or width of each wall and write them down. If you multiply both dimensions, you get the wall or ceiling area. In the case of cuboid rooms, it is sufficient to measure the width, length and height of the room. All other dimensions then result from this.

Almost all products indicate the area for which the material is sufficient. Just for a rough guide: A sack with 30 kilograms of gypsum plaster is enough for about two and a half square meters of wall surface with a plaster thickness of ten millimeters. However, there may be deviations depending on the desired plaster thickness.

Plaster rails must be installed over the entire height of the room, a rail comes every 40 to 60 centimeters, with a distance of 20 to 40 centimeters at the wall corners. In the end, it also depends on how big the screed is.

2. Prepare the room and wall

In the case of a new building, the room usually does not have to be specially prepared. If no floor has yet been laid, it is not even necessary to cover the floor with painter's fleece. In the case of old buildings, however, wallpaper, paint and old plaster must be removed from the wall. Because this inevitably creates dirt, it is worth laying painter's fleece and so-called milk carton paper over it. This paper is very stable, it can be cleaned from time to time during a longer work process and, like the painter's fleece, reused after the work is finished.

In residential construction, dry building materials are sometimes used, which replace the interior plaster, i.e. do not have to be plastered. In some cases, surfaces such as wood, metal or concrete should be plastered. In such special cases, if in doubt, you should seek advice from a hardware store or a professional, as it is not always obvious to the layman how exactly the covering needs to be plastered.

  • Wood cannot be plastered because wood changes over time and the plaster would crack. A wooden wall must therefore first be clad with plaster base plates, plaster grids or reed mats, for example.
  • With a surface off metal As a rule, rust protection must first be applied. Then expanded metal - a kind of metal grid - can be installed, which serves as a plaster base.
  • concrete must cure sufficiently. How long this takes depends on the type of concrete and the thickness of the wall. Whether or not the substrate needs to be prepared also depends on the concrete used. Concrete is often installed as exposed concrete, which is then not plastered.

3. Prime and wet the wall

If the wall is clean, it must be primed next. Which primer is the right one depends on the absorbency of the wall. To determine the absorbency of a wall, do-it-yourselfers can lightly dampen the surface with water:

  • If individual drops remain, the subsurface is not absorbent;
  • if the water draws in slowly, one speaks of normal suction;
  • if it is absorbed immediately, it is highly absorbent.

Based on this test, the primer can be selected:

  • non-absorbent substrate: special adhesive primer
  • little absorbent: normal primer
  • highly absorbent: deep adhesive primer
  • Plasterboard: deep adhesive primer
  • greasy walls, walls contaminated with nicotine or other substances: bulky adhesive primer
  • Brick walls: plaster base

Now that the wall is clean and primed, the wall should be soaked before it is plastered. To do this, water is sprayed onto the wall with a broad, bristle brush, often referred to as a tassel or paste brush. Do-it-yourselfers shouldn't be too timid: a wall to be plastered should be damp.

4. Set profiles

Professionals can now start plastering immediately, but it is easier with plaster profiles:

  • Quick cleaning strips help to apply the plaster evenly. In addition, they also help level out crooked walls. One day before plastering, the strips are installed vertically on the walls at a distance of about 40 to 60 centimeters.
  • Corner profiles protect edges from damage and wear. They are also installed one day in advance and then plastered over.

The assembly is carried out with so-called corner rail mortar. A dab of mortar every 30 to 40 centimeters is enough. The plaster rails are then pressed into the mortar and perfectly aligned with the help of a level or straightedge.

5. Mix and apply plaster

Now water and plaster mortar are mixed according to the manufacturer's instructions, for example in a large bucket or tub. This is not so easy, especially with larger quantities. For a good result you need a stirrer that can be mounted on a drill.

Most of the walls to be plastered are not smooth or at least have joints that need plastering. With such uneven surfaces, plaster is usually thrown on the wall with a trowel or spatula and then roughly spread over. By throwing the plaster into fine cracks and grooves. This start takes practice. But if you use plaster rails, it is easier because the plaster layer does not have to be level in the first step. Only in the next step is the surface smoothed with the help of a leveling batten and the plaster rails.

After the plaster has dried, minor unevenness can be sanded off with the grid-Rabot. Such a lattice rabot looks like a float, but a lattice is mounted on the handle.

There should be a small gap between the ceiling and the freshly applied layer of plaster on the wall, otherwise the plaster may later crack. To do this, brush directly along the ceiling with a clean trowel and thus separate the new layer of plaster from the ceiling.

6. Smooth or structure plaster

At the end, the plaster can be smoothed or textured. The structure is worked in while the plaster is still damp. For example, you can simply work on granular plaster with a float. Even with material that at first glance is not necessarily suitable, creative surfaces can be created, for example with a broom or by pressing bubble wrap into the plaster.

There are also numerous different methods of smoothing the plaster. The surface of the already dried plaster can be worked on with a sponge board or removed with a sanding mesh. Another option is lime smoothing, which is applied with a trowel and smoothed out with the facade spatula.

Always clean the tool immediately after use. Dried-on remaining plaster is difficult to remove.

Clay, lime or gypsum: types of plaster

Not all plasters are created equal: the different types of plaster are differentiated according to the binding agent added. This binding agent is usually mineral, i.e. it consists of plaster of paris, lime, cement, clay or a combination of these materials.

  • Gypsum plaster is only weather-resistant to a limited extent, so it is more suitable for indoor use. It regulates the humidity in the room, so it absorbs excess humidity and releases it again when necessary.
  • Lime and lime cement plaster can be used inside and outside. Lime plaster is highly alkaline, so it has a disinfectant effect and prevents mold growth. Do-it-yourselfers should make sure that their skin does not come into contact with the damp plaster, as it is extremely corrosive.
  • Clay and clay gypsum plasters should only be used indoors as they swell when damp. They have a moisture-regulating effect and store heat.
  • Synthetic resin plaster is relatively elastic and copes well with extreme environmental conditions such as heat, cold and moisture, so cracks are unlikely. The plaster is diffusion-proof and is therefore mainly used outdoors.

In addition, in the case of plaster, a distinction can also be made between base or base plasters and finishing or decorative plasters. A special form of wall design enables high-quality plasters, such as the waterproof surface finish Tadelakt, an ancient Moroccan lime plaster.

Facade: plaster the outer wall

In principle, exterior plaster is processed in the same way as interior plaster. Machine plasters are mostly used outside, however. As with interior plaster, the masonry must be clean and stable. Highly absorbent substrates such as bricks or aerated concrete should be primed with adhesive emulsion. Here, too, the mostly mineral plaster is applied to the wall in sections and always wet on wet.

Since the plaster must not dry out, the temperature should not be below five and not above 30 degrees Celsius. The plastered wall should also be protected from strong sun or driving rain while it is drying. That means: it is best to plaster in dry but cloudy weather. The scaffolding, which is required in most cases when plastering the external facade, also provides a certain protection.

Conclusion: plastering the wall yourself

Plastering a wall yourself is not that complicated. Whether the work is done in-house or by a specialist is therefore more a question of time: the experienced plasterer is usually twice as fast as the less experienced hobby handyman. The specialist company, including preparatory work, needs one to one and a half days for 20 square meters of indoor space, a do-it-yourselfer usually needs two. Ultimately, it's the result that counts. Do-it-yourselfers should be realistic about their own abilities - and invest their time in other projects if necessary.

Matthias Dittmann


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