Rendering sand, also known as plastering sand or sharp sand, is a specific type of sand used in the process of rendering walls. It's a crucial component in creating the smooth, protective layer applied to exterior and interior walls.
Key Characteristics of Rendering Sand
Rendering sand isn't just any sand; it has specific characteristics that make it suitable for its purpose:
- Sharpness: The term "sharp" refers to the angular shape of the sand particles. This angularity helps the sand bind effectively with cement or lime to form a strong and durable render. Unlike smoother sands which might slip, sharp sand interlocks, providing excellent structural integrity.
- Particle Size: The particle size of rendering sand is carefully graded to ensure the mix is workable and provides a smooth finish. It is typically coarser than fine sand but finer than construction aggregates.
- Cleanliness: Rendering sand should be free from impurities such as silt, clay, and organic matter. These impurities can weaken the render and cause problems like cracking or staining.
- Application: Rendering sand is specifically designed to be mixed with cement or lime to create the render, which is applied to surfaces such as brick, blockwork, or concrete.
Uses of Rendering Sand
- Wall Rendering: As its name suggests, the primary use is for rendering walls, creating a weatherproof layer which improves the aesthetic appeal.
- Plastering: It's also a key ingredient in some plaster mixes, especially for external walls.
- Mortar Mixes: Though more often used for rendering, sharp sand is sometimes included in certain mortar mixtures, especially when a high level of bonding strength is needed.
- Patching and Repairs: Sharp sand is often used to make render mixes that are then used for patching holes and repairing damaged wall areas.
Delivery and Handling
- Rendering sand is often delivered in a dumpy bag.
- It's typically delivered using a crane offload delivery vehicle, especially in bulk.
- The way it's delivered and handled on-site is crucial to prevent contamination.
Types of Rendering Sand
While the terms are often used interchangeably, different types may include slight variations:
- Sharp Sand: The generic term often used to describe rendering sand, it focuses on the angularity of the grain.
- Plastering Sand: A term highlighting its use for creating plasters (internal and external).
- Rendering Sand: The term most closely connected to the specific task of wall rendering.
In summary, rendering sand is a carefully selected, sharp, and clean sand specifically designed to be mixed with cement or lime to create durable and smooth wall render or plaster. It plays a crucial role in construction and building maintenance.
