Difference Between Cement, Plaster And Mortar – Properties

Difference Between Cement, Plaster And Mortar – Properties

Numerous materials are used on construction sites and even at home, some of which look confusingly similar. Cement, plaster and mortar are always to be found, which are confusingly similar due to their color. Nevertheless, these building materials are used for completely different tasks and must therefore be compared with one another so that the wrong material is not used for the construction project.

Plaster, mortar and cement are basic materials in construction and are required for large-scale projects such as an apartment building, but also for simple walls in private gardens. On the construction site, they are among the gray materials that can hardly be distinguished based on their color and consistency, but can be distinguished in their use and properties. Although the three fabrics look so similar, they are used for completely different purposes and for this reason it is important that you can distinguish them. This way you don’t run the risk of using the wrong building material and jeopardizing the completion of the project.

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Common ground: raw materials

Despite their different properties, the three building materials consist largely of the same raw materials:

  • limestone
  • sand
  • volume

This is also the reason why they look so similar in terms of color and are difficult or impossible to tell apart at first glance. For the individual substances there are also additives that make the building material usable for the respective purpose, such as liquefiers or dyes. The building materials are closely related, but it is the additives that determine the final use. Most of these building materials are offered in dry form and mixed with water or special solutions.


What is cement?

Cement is one of the most important building materials, which was already known to the Romans in a slightly different form and was called “opus caementicium” there. Basically, “quarry stone”, from the Latin caementicium, is a binder for construction projects, which is an essential substance of the following end products;

  • cement mortar
  • concrete

It is generally a mineral building material that consists mainly of lime and clay. These two raw materials are enriched together with quartz sand and iron ore and ground together, which is the basic form of cement. This mixture is then burned at a temperature between 1,400 and 1,500°C, resulting in the so-called cement clinker, small balls of the mineral substances in the cement. These balls are quite hard and can be easily mixed with other substances, which then determine the type of cement:

  • slag sand
  • fly ash
  • plaster
  • limestone
  • other inorganic additives
  • other natural additives

If these substances are added to the previous mixture, the product cement is created, which is essential in today’s industrial house construction and even for your own projects in the house and garden. In order to be able to use the cement mixture, it is mixed with water in an appropriate ratio, which results in cement paste. Cement is not actually used on its own, even if the building material is hard as stone, but is not durable and is therefore mixed with other materials to create a weather-resistant end product or one that is appropriate for the purpose:

  • Concrete: sand, gravel and water
  • Mortar: water and sand

Due to the easily binding properties of the cement, it can easily be used with other rocks and can therefore be used as a binder. An important classification can still be found with cement, because the raw materials used also define the type of cement:

1. Portland cement: Portland cement is understood as the classic of today’s cement, which was patented in 1824 by the British Joseph Aspdin and named after the limestone island Isle of Portland, which is reminiscent of the typical gray cement in color. This consists of 90 percent Portland clinker, which consists of the substances described above and is the most common basis for concrete and mortar. Its cheap production and easy use make Portland cement an unmistakable material.

2. Trass cement: Trass cement is a special building material that not only consists of lime and clay, but also a maximum of 35 percent trass. Trass is rock of volcanic origin, which gives the trass cement its unique properties. This hardened volcanic ash, together with the other raw materials, enables a cement that has the following properties:

  • elastic
  • weather resistant
  • extremely resistant
  • protects against efflorescence
  • not prone to staining

Trass cement is not commonly used for the construction of modern high-rise buildings or the like, but for monuments and the use of natural stones.

Tip: Efflorescence (efflorescence) describes a condition in which salts are dissolved from the surface of the structure in the form of crystals or powder. The stronger these efflorescences are, the more these salts become encrusted and can severely damage the masonry.

What is mortar?

Mortar is not a binder when used, but a mass that can be shaped and is used to close gaps between building blocks. Mortar serves as “glue” for the building blocks and, due to its properties, ensures a good hold. The building material is an essential element for buildings made of bricks, bricks, and characteristic of their appearance. The properties of mortar also explain the use of the substance:

  • high elasticity
  • gets fast and stays hard
  • also a raw material of plaster (plaster mortar)

The grain size of the mixture differs from that of concrete. Since it contains no gravel, the maximum grain size is only four millimeters, which allows it to be used as a malleable building material. It can therefore be easily distributed and used precisely without drying too quickly and thus allowing possible changes. The areas of application of the mortar amount to:

  • walling up
  • plastering
  • Laying tiles
  • thermal insulation composite systems

However, not all mortar is the same. A distinction is made here between three basic types of mortar, which mainly relate to bricklaying:

1. Cement mortar: Cement mortar is a mixture of one part cement with five parts sand and is a fast-setting building material that is particularly resilient. The cement content makes the cement mortar a strong and waterproof mass, suitable for the following masonry:

  • buttress
  • vaulted ceilings
  • reinforced walls

In itself, the cement mortar is mainly used for construction projects that have to withstand high loads and it is perfect for this. Cement mortar is always recommended for outdoor use.

2. Lime mortar: Lime mortar is a mixture of one part cement, six parts sand and one part building lime (lime hydrate) and is used as interior plaster due to the given moisture regulation. It is easier to use than other mortars, but it can only withstand very little pressure and is therefore not suitable for all masonry. The water resistance is also not that high.

3. Cement-lime mortar: Cement-lime mortar is the classic construction mortar for most walls and is made from one part cement, one part quicklime, and six parts sand. It is easy to work with and thanks to the burnt lime, the mortar is more resistant.

In addition to these typical types of mortar, there are other types that depend on their respective additives, which also define the use:

  • thin bed mortar
  • tile grout
  • fireclay mortar
  • gypsum mortar

This is what makes the use of mortar so effective, as there is a suitable type for virtually every application.

What is plaster?

The plaster or plaster is actually a mortar enriched with binders of organic or mineral origin, used specifically for the finishing of masonry and buildings. The following goals are achieved by applying plaster:

  • Walls are smoothed
  • Walls are protected from weather influences
  • creates a surface texture

The use of the plaster is not limited to one form of masonry, but to certain areas within buildings. Above all, it protects the basic masonry from moisture or directs living space moisture from inside to outside, which makes it essential for house construction. It consists of the following components:

  • mortar
  • special binder

These binders are decisive for the type of plaster, because as with cement mortars, a different binder ensures a completely different application. The binding agent used also indicates the type of plaster. There are four general areas of application:

  • Base coat: levels out holes and unevenness in the masonry, is necessary for the application of the top coat
  • Finishing plaster: protects masonry from external influences of mechanical origin, such as rain falling from the vertical direction
  • Interior plaster: protects against temperature fluctuations indoors and ensures constant humidity
  • Exterior plaster: protects the masonry from the weather

Plaster is therefore essential to protect the building, while cement and mortar types ensure a stable construction. But plaster is not just plaster, as already indicated above. The different types of plaster are divided according to the respective binding agent, which is already included in the name and is contained in different proportions depending on the manufacturer and purpose:

  • Gypsum plaster: suitable for dry interiors such as living rooms or hallways, is often used as a base for wallpaper
  • Lime plaster: classic for damp interiors such as bathrooms or basements, works effectively in older buildings
  • Synthetic resin plaster: Finishing plaster with high resistance, can be used as a decorative plaster and can be easily applied with a paint roller
  • Lime cement plaster: Exterior plaster, common for all types of facades
  • Cement plaster: Exterior plaster, is mainly used for the base area
  • Clay plaster: one of the oldest forms of plaster, especially suitable for walls and ceilings, often used as colored decorative plaster

Tip: There are also unique plaster types such as scratched and mosaic plaster, which are specially processed and thus create an artistic surface.