Mortar and grout are both cement-based materials used in construction, but they serve distinct purposes. The key difference lies in their application and composition.
Mortar: The Foundation
Mortar acts as a bonding agent, primarily used to adhere tiles to a surface or substrate. Think of it as the "glue" that securely holds bricks, stones, or tiles to the underlying wall or floor. It's a stiffer, more plastic mixture than grout, allowing for a strong, durable bond. While similar in some properties, mortar differs in sand fineness, additives, and the inclusion of lime, which is absent in grout. The lime in mortar can, over time, lead to efflorescence (a white, chalky film).
Grout: Filling the Gaps
Grout, on the other hand, fills the gaps and seals the spaces between tiles. It's a finer, more fluid substance designed for this specific purpose. It's crucial for creating a waterproof and aesthetically pleasing finish. The water content in grout is significantly higher than in mortar to achieve its pourable consistency.
Summary Table:
| Feature | Mortar | Grout |
|---|---|---|
| Primary Use | Bonding agent for tiles and masonry | Filling gaps between tiles |
| Consistency | Stiffer, more plastic | Finer, more fluid, pourable |
| Lime Content | Contains lime | Does not contain lime |
| Sand Fineness | Relatively coarser sand | Finer sand |
| Additives | May contain various additives | May contain various additives (often different than mortar) |
Practical Examples:
- Laying bricks: You would use mortar to bond bricks together in a wall.
- Tiling a bathroom: You'd use mortar to adhere tiles to the wall or floor, and grout to fill the spaces between them.
In short, mortar bonds materials together, while grout fills the spaces between them. This fundamental difference dictates their composition and application.
