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How to Make Jamb Mortar?

How to Make Jamb Mortar

Today, I’ll walk you through the step-by-step process of preparing jamb mortar, a widely used material in the construction sector that adds aesthetic appeal to architectural details. Jamb mortar is typically applied on materials like polystyrene foam to enhance the appearance of exteriors. Let’s delve into how to prepare jamb mortar and what considerations to keep in mind.

What is Jamb Mortar?

Jamb mortar is a material commonly used in exterior decoration, plastering, and decorative applications. It is applied on materials like polystyrene foam to achieve a decorative look. Additionally, it can provide an additional insulation layer, contributing to energy efficiency.

Materials Required for Jamb Mortar

To prepare jamb mortar, you will need the following materials:

  • Polystyrene foam or other insulation materials
  • Cement
  • Sand
  • Water
  • Optional additional insulation materials
  • Tools such as a trowel, spatula, etc.

Step-by-Step Process of Preparing Jamb Mortar

  1. Preparation of Polystyrene Foam: Start by cutting and preparing the polystyrene foam to the desired shape and size. It’s crucial to cut the foam according to the dimensions and shape of the surface where the jamb mortar will be applied.
  2. Mixing the Mortar: In a bucket or mortar pan, mix cement, sand, and water in specific proportions to obtain a homogeneous mixture. The consistency of the mixture should be such that it can be easily applied.
  3. Application of the Mortar: Use a spatula or trowel to evenly spread the prepared mortar onto the polystyrene foam. Ensure that the mortar is evenly applied over the entire surface of the foam to achieve a smooth finish.
  4. Adding Insulation Materials (Optional): If necessary, add additional insulation materials onto the applied mortar and ensure they are properly placed. This step is optional and can be chosen to add an extra insulation layer to the structure.
  5. Drying Process: Allow the mortar to completely adhere to the polystyrene foam and dry for a specific period. The drying time may vary depending on environmental conditions and the materials used. Once the mortar is fully dried, you can proceed with exterior decoration or plastering.

Techniques and Tips for Applying Jamb Mortar

  • When applying the mortar onto the polystyrene foam, ensure it is spread evenly and smoothly. Uneven distribution of the mortar can result in difficulties in achieving a smooth finish in subsequent steps.
  • Regularly check and adjust the consistency of the mortar mixture by adding or removing water as needed to achieve the desired consistency.

Maintenance and Durability After Applying Jamb Mortar

Once the jamb mortar has dried completely, you can apply exterior paint or a finishing coat as desired. Additionally, regular maintenance is essential to enhance the durability of the jamb mortar. This can contribute to a long-lasting and aesthetically pleasing appearance for your structure.


Jamb mortar is a significant construction material that enhances the aesthetic appeal of exteriors and provides an additional insulation layer. By following the steps outlined above, you can easily prepare jamb mortar and add an aesthetic touch to your structures. Remember, selecting the right materials and application techniques can improve the durability and longevity of jamb mortar.