What is the Difference Between Plastering and Screeding: A Comprehensive Guide

Have you ever wondered what the difference is between plastering and screeding? While both of these techniques are used in construction and renovation projects, there are distinct differences in their purposes. Plastering is a method used to finish walls and ceilings with a smooth and even surface, while screeding is used to create a level base for floors before tiling or carpeting.

Plastering is a popular technique that is often used to create an aesthetically pleasing finish to walls and ceilings. It involves the application of a layer of plaster onto a surface and then smoothing it out to create a level finish. This method is commonly used to refresh the appearance of older walls and ceilings or to create a new look for a room. In contrast, screeding is primarily used in the preparation of a floor. The screed acts as a levelling agent, ensuring that the surface is even and ready for the next step in the process.

Both plastering and screeding are crucial techniques that play an important role in the creation of modern buildings. While they share similar methodology and techniques, they ultimately serve different purposes. Understanding the difference between these two techniques is key to making informed decisions for any construction or renovation projects you might be undertaking. So, the next time you’re planning a home improvement project, it’s worth considering whether plastering or screeding would be the better option for your particular needs.

Importance of surface preparation in plastering and screeding

Surface preparation is essential in both plastering and screeding to ensure a smooth, level finish and a strong bond between the substrate and finishing material. Neglecting proper surface preparation can lead to a range of issues, including cracking, peeling, and poor adhesion, which will ultimately compromise the quality and durability of the finished product.

  • Cleanliness: The surface must be thoroughly cleaned of any dust, dirt, debris, and loose particles before plastering or screeding can begin. A dirty surface can prevent the finishing materials from adhering correctly and can also cause contamination, which can lead to discoloration or staining.
  • Leveling: Any unevenness or bumps on the surface must be smoothed out or leveled before plastering or screeding can commence. Uneven surfaces can cause bubbles, cracks, or shrinkage in the finishing material and can also highlight imperfections in the final product.
  • Dryness: The surface must be completely dry before plastering or screeding begins. Moisture can interfere with the curing process of the finishing material, leading to shrinkage, cracking, and weakened adhesion.

Aside from the above, there are other factors to consider depending on the type of substrate and finishing material, such as the type of primer or bonding agent required, the appropriate thickness of the finishing layer, and the curing and drying times of the products used.

Proper surface preparation not only ensures a high-quality finish but also saves time, money, and effort in the long run. It avoids the need for costly and time-consuming repairs and replacements, which often occur due to inadequate preparation measures.

Therefore, it is best to consult with an experienced professional who can evaluate the surface and determine the appropriate preparation measures needed to achieve a flawless and durable finish.

Materials Used in Plastering and Screeding

One key difference between plastering and screeding is the materials used for each task. Both plastering and screeding require a skilled tradesperson who can mix, apply, and finish the material to create a smooth and even surface. Below are the main materials used in plastering and screeding:

  • Plastering materials:
    • Plaster: The primary material used in plastering is a mixture of gypsum powder, water, and additives to create a paste-like substance that can be applied to walls and ceilings.
    • Backing coat: This is a rough coat applied to the surface before the plaster to create a strong bond with the substrate. The backing coat is typically made of sand and cement.
    • Finish coat: Once the backing coat is applied, the final plaster layer is applied on top and smoothed out to create a smooth and even surface. This layer can be lime plaster, cement plaster, or gypsum plaster.
  • Screeding materials:
    • Screed: This is a thin layer of cement and sand that is applied to a concrete floor to level it out before the final floor finish is added. Screed can be mixed off-site and transported to the site or mixed on-site using a ratio of 1 part cement to 3-5 parts sand.
    • Additives: Different additives can be added to the screed mixture to enhance its properties, such as plasticizers to increase workability or moisture-retaining compounds to prevent the screed from drying too quickly.

Examples of Plastering and Screeding Materials

In the UK, some of the most popular plastering materials are:

  • British Gypsum Thistle Board Finish: A gypsum plaster that is ready-mixed with a smooth and high-quality finish. It is used for finishing walls or ceilings in drylining systems.
  • Knauf MP75 Projection Plaster: A machine-applied gypsum plaster that is ideal for large projects where speed and consistency are essential.
  • British Gypsum Thistle Multi-Finish: A gypsum finishing plaster that provides a smooth, durable, and high-quality finish on walls and ceilings.

For screeding, some popular materials include:

Material Description
Traditional screed A sand and cement mixture with a 3:1 ratio. It is most commonly used in industrial and commercial buildings.
Self-leveling screed A premixed blend of cement, aggregate, and additives that is designed to self-level when poured on a surface. It is ideal for use in homes and other residential buildings.
Anhydrite screed A self-leveling screed made from calcium sulfate anhydrite. It provides high thermal conductivity and is ideal for use with underfloor heating systems.

Overall, the materials used in plastering and screeding differ based on the specific task at hand. Plastering requires specific types of plaster, backing coats, and finish coats, while screeding requires a mix of cement and sand, as well as different additives to enhance its properties.

Techniques for Applying Plaster and Screed

Plastering and screeding involve different techniques for their application. The process of plastering involves the application of a mixture of sand, water, and cement to a surface to achieve a smooth and even finish. Screeding, on the other hand, involves leveling and smoothing out a concrete subfloor in preparation for the installation of flooring. Here we’ll take a closer look at the techniques used for the application of plaster and screed.

Techniques for Applying Plaster

  • Troweling: This involves applying the plaster mixture to the surface with a trowel and then smoothing it out using a second trowel.
  • Spraying: This method involves applying the plaster mixture using a spray gun.
  • Rendering: This technique involves applying a thicker coat of plaster to a surface, usually for exterior walls or where more durability is required.

Techniques for Applying Screed

Screeding involves the use of specialized tools and techniques to achieve a level and smooth concrete subfloor. The following are some of the commonly used techniques for screeding.

  • Traditional screed: This method involves the manual application of a liquid screed mixture onto a subfloor and leveling it with a screed board.
  • Laser screed: A mechanical screed guide is used to level the concrete to a precise level, up to 0.5mm tolerance.
  • Self-leveling screed: This involves the application of a liquid mixture that self-levels and is designed to achieve a level surface without needing to be smoothed out.

Plaster vs. Screed: Comparison

Although both plastering and screeding result in a smooth and even surface, there are differences in the techniques used, as well as the materials used for each process. The table below outlines the key differences between plaster and screed.

Technique Material Application
Plastering Sand, water, cement, and additives Applied directly onto surfaces
Screeding Concrete mixture and additives Applied to subfloor to create a level surface for flooring

In conclusion, both plastering and screeding require specialized techniques for their application, and the choice of technique depends on the project requirements. While plaster is applied directly onto walls and ceilings to create a smooth and even surface, screed is applied to subfloors to level them in preparation for flooring. Regardless of which technique is used, it is always recommended to hire a professional to ensure the best results.

The role of humidity and temperature in plastering and screeding

Humidity and temperature play a significant role in the plastering and screeding process. These elements can affect the quality and durability of the finishes, and ignoring them can lead to unsatisfactory results or failures.

  • Humidity: High humidity levels can cause slower drying time. In plastering, excess humidity can create cracks, surface defects, and delamination. In screeding, high humidity can cause poor bonding, shrinkage, and uneven surfaces. Therefore, it is crucial to ensure proper ventilation and suitable moisture levels in the working area. Modern breathable plasters can help reduce the risk of moisture problems.
  • Temperature: Temperature also affects the curing and drying process of plastering and screeding. The optimal temperature range for plastering is between 5°C and 30°C (40°F to 86°F). Low temperatures can slow down the reaction time, while high temperatures can cause too rapid drying, leaving the surface porous and weak. In screeding, low temperatures can cause shrinkage, while high temperatures can lead to cracking. It’s essential to follow the manufacturer’s guidelines and use suitable additives or admixtures to adjust the setting time and drying properties of the materials in different weather conditions.

Therefore, to ensure the best results, it’s crucial to monitor and regulate the humidity and temperature levels during the plastering and screeding process. Professional contractors use hygrometers, thermometers, and moisture meters to measure the ambient conditions and adjust the application accordingly. Using quality materials, proper mixing, and adequate curing techniques can also help to minimize the impact of humidity and temperature variations.

Factor Plastering Screeding
Humidity Excess humidity can cause cracks, surface defects,  delamination Poor bonding, shrinkage, and uneven surfaces
Temperature Optimal range 5°C to 30°C (40°F to 86°F). Low and high temperatures can cause damage to surfaces Low temperatures can cause shrinkage, while high temperatures can lead to cracking

Overall, considering the role of humidity and temperature in the plastering and screeding process is essential to achieve high-quality, long-lasting finishes. By controlling these factors through proper preparation, application, and curing, contractors can deliver satisfactory results and meet their customers’ needs.

Tools required for plastering and screeding

Plastering and screeding are two different techniques that require different tools and equipment to complete. Here are the tools required for plastering and screeding:

  • Trowel – This is a flat, rectangular tool with a handle that is used to apply, smooth and spread plaster or screed on a surface. A trowel can be made of different materials such as wood, plastic or stainless steel depending on the type of work.
  • Hawk – This is a flat, square surface with a handle that is used to hold and carry the plaster or screed while working. A hawk can be made of different materials such as wood, plastic or stainless steel.
  • Mixing bucket – This is a large, plastic bucket that is used to mix the plaster or screed with water. It can be found in different sizes depending on the amount of material being mixed.

Plastering and screeding also require different types of finishing tools:

  • Float – This is a large, flat tool that is used to finish and smooth the surface of the plaster or screed. A float can be made of different materials such as wood or plastic.
  • Edging trowel – This is a pointed, triangular shaped tool that is used to create sharp edges and corners on the surface of the plaster or screed.
  • Spirit level – This is a tool that is used to ensure that the surface being plastered or screeded is level and even. It can be found in different sizes from small handheld levels to larger ones.

In addition to these tools, screeding may require the use of a straightedge – a long, straight tool used to level and smooth the surface of the screed.

Plastering tools Screeding tools
Trowel Spirit level
Hawk Mixing bucket
Float Straightedge
Edging trowel

Having the right tools can make a significant difference in the end result of plastering and screeding. It’s crucial to use the proper tools and equipment to achieve a smooth, level and high-quality finish.

Common problems encountered in plastering and screeding

Plastering and screeding are essential steps in building construction, and both have their own unique challenges. Here are some common problems encountered in plastering and screeding.

  • Cracks in the plaster – One of the most common problems in plastering is the occurrence of cracks on the plaster. These cracks occur due to several reasons such as inadequate curing, improper mix of materials, and the presence of moisture.
  • Uneven plaster – Another common problem in plastering is the unevenness of the plaster surface. This issue is prevalent when the plaster is not appropriately applied or when the surface is not levelled before the application of plaster.
  • Curling in screed – Curling in screed is a common problem that occurs when the screed surface rises at the edges, creating a curling effect. This problem occurs due to the inadequate mix of materials, poor compaction, and insufficient curing.

Causes of common problems in plastering and screeding

The major causes of the common issues encountered in plastering and screeding include:

  • Improper mixing of materials – The improper mixing of materials can result in weakened plaster or screed, which can lead to cracks, unevenness, and curling.
  • Inadequate curing – Inadequate curing results in poor-quality plaster and screed, making them vulnerable to damage, cracks, and curling.
  • Poor surface preparation – Poor surface preparation before plastering or screeding can cause unevenness, leading to poor-quality surfaces after application.

Preventive measures for common problems in plastering and screeding

To prevent the occurrence of the common problems in plastering and screeding, several measures can be taken, including:

  • Proper mixing of materials – Ensure a proper mix of materials before plastering or screeding.
  • Adequate curing – Adequately cure the plaster or screed to prevent common problems.
  • Proper surface preparation – Ensure that the surface is correctly cleaned and levelled before application of plaster or screed.

Tips to fix common problems encountered in plastering and screeding

If common problems are already present in plastering and screeding, follow these tips to fix them:

Problem Solution
Cracks in plaster Use filling materials to cover the cracks. The surface can then be sanded and repainted.
Uneven plaster Remove the uneven plaster and reapply the plaster with proper surface preparation and leveling.
Curling in screed Remove the curled screed and reapply the screed correctly. Ensure proper mixing, compaction, and curing in the new screed.

With these preventive measures and solutions, you can ensure that your plastering and screeding are of high quality and devoid of common problems.

Different types of plaster and screed for various applications

When it comes to construction, the materials used for plastering and screeding may vary depending on the specific application. There are different types of plaster and screed available in the market that cater to different needs and requirements. In this article, we will discuss the various types of plaster and screed that are commonly used in different applications.

Types of Plaster

  • Lime plaster: Made from a mixture of sand, water, and lime, this type of plaster is commonly used for historic restoration and conservation projects.
  • Gypsum plaster: Made from gypsum, water, and additives, this type of plaster is widely used in modern construction and is ideal for finishing interior walls and ceilings.
  • Cement plaster: Made from a mixture of cement, sand, and water, this type of plaster is commonly used for exterior walls and in areas where high impact resistance is required.

Types of Screed

Just like plaster, screed also comes in different varieties. The appropriate type of screed for a construction project will depend on factors such as the intended use of the floor, the thickness required, and the type of substrate.

  • Anhydrite screed: Made from a mixture of gypsum, water, and additives, this type of screed is commonly used for under-floor heating systems due to its good thermal conductivity.
  • Sand and cement screed: Made from sand, cement, and water, this type of screed is the most commonly used and is ideal for leveling out uneven floors.
  • Self-leveling screed: Made from a mixture of cement, sand, and additives, this type of screed is used to level floors quickly and efficiently.

Plaster and Screed Applications

While each type of plaster and screed has its individual qualities and properties, they are mostly used for the same applications across the construction industry.

Some of the common applications of plaster are:

  • Finishing interior walls and ceilings
  • Restoring historic buildings
  • Making decorative finishes
  • Repairing cracks and damages on walls and ceilings

Screed, on the other hand, is commonly used for the following applications:

Application Type of Screed
Leveling floors Sand and cement screed
Under-floor heating Anhydrite screed
Quick installation Self-leveling screed

Knowing the different types of plaster and screed available for each application, along with their respective strengths and weaknesses, is crucial in achieving a successful construction project.

What is the Difference between Plastering and Screeding?

1. What is plastering?
Plastering is an interior finishing technique that is used to provide a smooth, even surface on walls and ceilings. It involves the application of a mixture of plaster and water onto the walls.

2. What is screeding?
Screeding is a leveling procedure that is used on floors to provide a smooth, even surface. It involves the use of a thin layer of cement or a sand-cement mixture, which is applied to the surface of the floor.

3. What is the difference between plastering and screeding?
The key difference between these two techniques is that plastering is used on interior walls and ceilings, while screeding is used on floors. Additionally, the materials used are different, with plastering using a plaster and water mix, and screeding using a cement or sand-cement mix.

4. Can they be used interchangeably?
No, plastering and screeding are not interchangeable techniques. They are both used for different purposes and on different surfaces.

5. Which technique should I use?
The choice of which technique to use depends on the surface to be treated. If you are looking to smooth out your walls and ceilings, then plastering is the way to go. If you are looking to level your floors, then screeding is the better choice.

Closing Thoughts

Thanks for taking the time to read about the difference between plastering and screeding. Remember to choose the appropriate technique based on the surface you are working on. We hope you found this article informative. Come back soon for more helpful tips!