How to Choose the Right Type of Mortar for Wall Rendering?

Choosing the right type of mortar for wall rendering is an important step in ensuring that any home improvement project is successful. Mortar is used to bond bricks and blocks together, so it’s essential to choose the correct mix to ensure a strong, lasting bond.

The choice of mortar must also take into account other factors such as porosity, thermal movement and the presence of dampness. In this article, we’ll look at the different types of mortars available and how they can be used for wall rendering so you can make an informed decision when planning your next project.

Cement mortar

Understanding Different Types of Mortar

Before selecting a particular type of mortar, it’s important to understand what each variety may offer. Generally speaking, there are three main types of mortar: sand and cement, lime-based and gypsum.

Sand and cement mortars are the most common type used for wall rendering. This mixture produces a strong bond between blocks or bricks that can withstand a considerable amount of pressure from external sources.

The mix is typically composed of one part Portland cement, two parts washed building sand, and water to form a thick paste. This type of mortar is best suited for exterior walls exposed to severe weather conditions due to its strength and durability.

Lime-based mortars, on the other hand, offer more flexibility than sand and cement mixtures. In fact, these types of mortars are much more workable than their counterparts; they are also able to absorb moisture.

This makes them an ideal choice for walls that are likely to experience thermal movement or dampness. Additionally, lime-based mortars are better suited for older buildings that have walls composed of softer materials such as mud bricks or cobblestones.

Finally, gypsum mortar is used in cases where a strong bond is not necessary but waterproofing is required. This type of mortar offers great insulation and water resistance when applied correctly, making it suitable for bathrooms and wet areas. It’s essential to understand the differences between these three types of mortars before selecting one for your project.


What Type of Mortar Is Best For Wall Rendering?

When choosing the right type of mortar for wall rendering, it’s important to consider the following criteria: porosity, thermal movement and dampness. Sand and cement mixtures are the most common choice for exterior walls exposed to harsh weather conditions because of their strength and durability.

However, if your walls may experience thermal movement or dampness then a lime-based mortar is a better option due to its greater flexibility. For bathrooms and wet areas, gypsum mortar should be used for waterproofing purposes.

In addition to taking into account these factors, you must also ensure that the mix chosen has been designed specifically for wall rendering. This will help to guarantee a strong bond between bricks or blocks that can stand up to external pressure while allowing enough flexibility for thermal movements and water absorption.


Tips for Applying Mortar to Walls for Rendering

  • Once you’ve selected the appropriate type of mortar for your project, it’s important to follow these tips when applying it to your walls:
  • Prepare the surface by removing any existing dirt, dust and debris before applying the mortar.
  • Apply the mortar in small batches over a period of time rather than all at once. This will ensure that each layer is properly cured and set.
  • Use a trowel to spread and level out the mortar as much as possible without creating air pockets or gaps.
  • Allow each layer to cure completely before adding another layer. This will prevent cracking during curing.
  • If using a lime-based mortar, make sure to keep the area damp in order to encourage proper curing.



Choosing the right type of mortar for wall rendering is essential in ensuring that your project will be successful and last for years to come. Sand and cement mixtures are best suited for exterior walls exposed to harsh weather conditions while lime-based mortars provide more flexibility for walls with thermal movement or dampness.

Gypsum mortars offer strong waterproofing capabilities that make them ideal for bathrooms and wet areas. Finally, by following these tips you can ensure that your mortar application is done correctly and efficiently. With this knowledge, you’re now equipped to choose the most suitable type of mortar for wall rendering so that you can achieve the desired results.


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