Surkhi mortar is a type of traditional lime mortar used in South Asia, particularly in India. It is made by mixing lime, surkhi (powdered burnt clay), and water. Surkhi is obtained by grinding burnt clay bricks or tiles into a fine powder.
It is known for its high durability, water resistance, and strength. It is commonly used as a plastering material for walls and ceilings, as well as for laying bricks and stones in masonry work. It is also used as a bedding material for tiles and for making decorative elements like cornices, arches, and pillars.
Types of surkhi mortar
Lime-Surkhi Mortar: This is made by mixing lime, surkhi, and water. It is commonly used for plastering and masonry work, as it has good water resistance and durability.
Cement-Surkhi Mortar: This is made by mixing cement, surkhi, and water. It is commonly used for flooring and paving work, as it has good strength and is resistant to wear and tear. However, it is less breathable than lime-surkhi mortar and may not be suitable for certain applications.
How to prepare surkhi mortar
- Collect burnt clay or brick pieces and grind them into a fine powder to make surkhi.
- Mix the surkhi powder with water to form a paste.
- Leave the surkhi paste to mature for a few days, allowing it to undergo a pozzolanic reaction and become more reactive.
- In a separate container, mix the lime powder with water to form a lime putty.
- Add the matured surkhi paste to the lime putty and mix thoroughly to form the surkhi mortar.
- Adjust the water content as required to achieve the desired consistency of the mortar.
- Use the surkhi mortar for masonry work, pointing, or plastering.
Advantages of surkhi mortar
- It has high durability and can last for a long time, even in harsh weather conditions.
- It has excellent water resistance, making it suitable for use in damp areas such as basements, bathrooms, and kitchens.
- It is known for its high strength and is often used in the construction of load-bearing walls.
- It is a cost-effective alternative to modern cement-based mortars and is readily available in many parts of South Asia.
- It is an eco-friendly alternative to cement-based mortars as it produces less carbon dioxide emissions during production.
- It is easy to mix and work with, making it suitable for DIY projects and small-scale construction work.
- It has better adhesion than cement-based mortars, which reduces the chances of cracks and gaps in the finished work.
- It has a natural and rustic look, which makes it an ideal choice for heritage buildings and restoration work.
- It has good thermal insulation properties, which helps to keep the interiors of buildings cool in hot weather and warm in cold weather.
Disadvantages of surkhi mortar
- It has a longer setting time than cement-based mortars, which may increase the time required for construction work.
- The quality of mortar may vary depending on the quality of the surkhi and lime used in its production, which may lead to inconsistencies in the finished work.
- Although it has good strength, it may not be as strong as modern cement-based mortars, which may limit its use in certain construction projects.
- It is not suitable for use in areas with frequent freeze-thaw cycles, as it may crack or crumble under these conditions.
- It is not suitable for all types of construction work, and modern cement-based mortars may be a better option for certain applications.
Uses of surkhi mortar
- It is used as a plastering material for walls and ceilings.
- It is used for laying bricks and stones in masonry work.
- It is used as a bedding material for tiles.
- It is used for making decorative elements like cornices, arches, and pillars.
- It is an ideal choice for heritage buildings and restoration work due to its natural and rustic look.
