Plaster as a Functional and Aesthetic Layer

Within general masonry works, plastering may appear straightforward at first glance. In reality, it is a technically demanding process where every layer, the correct tools and even weather conditions play a vital role.

Plaster serves several important functions:

• protects walls from moisture penetration and condensation,
  
• levels uneven surfaces created during masonry work,
  
• creates a solid and even base for further finishes (painting, tiling),
  
• helps reduce thermal bridging and improves acoustic performance,
  
• increases the overall value of the property.
  

For these reasons, plaster must be applied correctly, using suitable materials and proper workmanship.

Which Plaster Is Best for Rough Walls?

The most common solution for residential properties and standard buildings is lime-cement rough plaster, which combines the strength of cement with the workability of lime. This type of plaster is:

• suitable for both internal and external use,
  
• resistant to moisture and mechanical damage,
  
• applicable by hand or machine,
  
• cost-effective and easy to repair.
  

According to current masonry pricing, plastering walls typically costs around €9.90 per m² excluding materials. Additional services often include:

• surface priming – €1.20 per m²,
  
• patch repairs – from €8.50 per m²,
  
• mesh reinforcement for partitions or joints – €9.60 per m².
  

These prices apply under standard conditions. More complex, heavily soiled or uneven substrates may increase the final cost.

Wall Plastering Process – Step by Step

1. Surface Preparation

Quality plastering always starts with thorough surface preparation. Dust, mortar residue and grease must be removed. The surface should be lightly dampened. A primer is often applied beforehand to equalise absorption and improve adhesion.

2. Installing Guide Rails

To achieve straight and level walls, guide rails are installed vertically at intervals of 1 to 1.5 metres. These allow the plaster to be applied evenly and levelled accurately.

3. Applying Lime-Cement Plaster

Plaster is usually applied in two layers. The first, thicker layer evens out major irregularities, while the second layer brings the surface to the required level. A single layer should not exceed 20 mm in thickness.
Where different masonry materials meet or in areas of increased stress, reinforcing fibreglass mesh is recommended to reduce the risk of cracking.

4. Levelling and Finishing

Once applied, the plaster is levelled using a straightedge and then smoothed with a trowel. For machine plastering, specialist tools are used to ensure a consistent surface texture.

5. Curing the Plaster

One of the most common mistakes is speeding up the drying process. Plaster must cure naturally, without direct sunlight, strong wind or frost. During this phase, light moistening is recommended to prevent cracking.

Factors That Affect Plaster Durability

The lifespan of plaster depends on more than just the mix used. Key factors include:

• substrate quality – dirty or highly absorbent surfaces reduce adhesion,
  
• layer thickness – overly thick layers crack, overly thin layers lack strength,
  
• proper climatic conditions – ideal temperatures range from 5 to 25 °C,
  
• type of masonry – different materials have different absorption rates,
  
• sufficient curing time – rushing the process shortens durability.
  

When Is It Worth Combining Plastering with Other Masonry Works?

If you are planning external walls, internal partitions or an interior refurbishment, plastering is the natural next step. It is often combined with:

• masonry reinforcement,
  
• patching and surface levelling,
  
• priming and preparation for painting,
  
• rough and fine plaster in a single phase.
  

Planning multiple tasks together helps optimise costs, reduce disruption and shorten overall project duration.

Plastering Is More Than Just “Covering” Walls

High-quality plaster is the result of professional workmanship, correct material selection and careful surface preparation. When applied properly, lime-cement rough plaster can last for decades without repairs. Ignoring proper procedures leads to cracking, peeling and repeated maintenance costs.

If you are looking for a reliable partner for masonry works, Numiq offers transparent construction pricing and an experienced team of tradespeople who ensure your walls are not only straight, but also built to last.
A well-executed plaster finish is like a tailored suit – it’s not just about appearance, but about how long it lasts. Trust the professionals.