The key difference between mortar and plaster is their primary function: mortar is used for bonding construction materials together, while plaster provides a smooth, protective finish to interior surfaces.
Here's a more detailed breakdown:
Mortar
- Function: Binds building blocks like bricks, stones, or concrete blocks together to form walls, foundations, and other structures. It provides structural integrity.
- Composition: Typically a mixture of cement, sand, and water. Lime may also be added for improved workability.
- Application: Applied between layers of masonry units, filling the gaps and creating a strong bond.
- Texture: Usually coarser than plaster due to the presence of sand.
- Location: Used primarily in exterior applications and for structural purposes.
Plaster
- Function: Provides a smooth, even, and protective finish to interior walls and ceilings. It can also be decorative.
- Composition: Typically made of gypsum, lime, or cement mixed with water. Additives may be included to control setting time, improve workability, or enhance durability.
- Application: Applied in one or more coats over lath (a backing material) or directly to masonry surfaces.
- Texture: Generally finer and smoother than mortar.
- Location: Used almost exclusively for interior applications.
Summary Table
| Feature | Mortar | Plaster |
|---|---|---|
| Primary Use | Bonding building materials | Finishing interior walls and ceilings |
| Location | Exterior and structural applications | Interior applications |
| Composition | Cement, sand, water (often with lime) | Gypsum, lime, or cement (with additives) |
| Texture | Coarse | Fine |
In essence, think of mortar as the glue that holds the bricks together, while plaster is the cosmetic coating that makes the walls smooth and appealing.
