When you work in construction, you often hear people mixing up mortar and grout. Although both materials look similar, they are not the same. In fact, choosing the wrong one can easily lead to weak joints, cracks, or even failed elements. Therefore, understanding the Difference Between Mortar And Grout is very important for every builder, mason, civil engineer, or homeowner starting a project.
Both mortar and grout are based on cement, sand, and water. Yet their behaviour, flow, use, and strength vary widely. So, in this blog, you will learn how they differ, where they are used, and which one is best for your job.
What Is Mortar?
Mortar is a workable paste used mainly to bond building units. It is thicker, stickier, and less flowable than grout. Additionally, it fills the gaps between bricks or blocks and helps transfer loads safely.
Key Features of Mortar
- Thick consistency: It must hold its shape on the trowel.
- Good bonding ability: It sticks well to bricks, blocks, and stones.
- Contains more sand: This gives it body and reduces shrinkage.
- Lower water content: Helps it stay stiff.
Common Uses of Mortar
- Brickwork and blockwork.
- Stone masonry.
- Plastering undercoats.
- Bedding tiles in some traditional works.
- Repairs in joints and pointing.
What Is Grout?
Grout is a highly flowable mix used to fill gaps, cracks, and voids. Compared to mortar, grout has much more water, which makes it thinner and easy to pour.
Key Features of Grout
- High flowability: It flows into tight spaces without leaving voids.
- Higher water-cement ratio: Helps it spread easily.
- Often contains additives: Plasticisers or non-shrink agents improve workability.
- Not meant for bonding bricks: It does not have the stiffness needed for that.
Common Uses of Grout
- Filling tile joints.
- Anchoring bolts, dowels, or rebar.
- Filling voids under baseplates.
- Post-tensioning ducts.
- Repairing cracks in concrete.
Main Difference Between Mortar And Grout
Although both mixes may look similar, they perform very different roles. Below is an easy comparison:
| Parameter | Mortar | Grout |
|---|---|---|
| Water content | Low | High |
| Flowability | Stiff | Very fluid |
| Main purpose | Bonding bricks/blocks | Filling voids |
| Sand quantity | Higher | Lower |
| Strength type | Better bonding | Better compression |
| Shrinkage | Low | Medium to high |
| Placement method | Trowelled | Poured or injected |
| Typical thickness | 10–20 mm | 1–10 mm (tile joints) or as required |
| Additives | Lime/plasticisers | Non-shrink agents, flow enhancers |
This table clearly shows the Difference Between Mortar And Grout, especially in terms of flow, strength, and purpose.
Which Is Best – Mortar or Grout?
There is no single “best” material. Instead, the right choice depends on the purpose.
Use Mortar When:
- You need to bond bricks or blocks.
- You want a stiff, durable bedding material.
- You are doing pointing or repairing joints.
- You require a mix that can hold shape.
Use Grout When:
- You need to fill gaps or cracks.
- You are installing anchors, bolts, or dowels.
- You are fixing tiles and need joint filling.
- You want a material that flows into narrow spaces.
So, mortar is best for bonding, while grout is best for filling.
IS Codes for Mortar and Grout
To ensure quality and safety on site, refer to the following Indian Standards:
- IS 2250 – Code of practice for preparation and use of masonry mortars.
- IS 4031 – Methods of physical tests for hydraulic cement.
- IS 650 – Standard sand for testing of cement.
- IS 9103 – Concrete admixtures (useful for grout plasticisers).
- IS 7861 – Safety and testing guidelines for grout used in prestressing.
These codes help maintain consistency, strength, and workability.
Advantages of Mortar
- Excellent bonding with bricks and stones.
- Easy to work with using basic tools.
- Reduces movement between units.
- Provides aesthetic finishing in joints.
Advantages of Grout
- Fills the smallest gaps without voids.
- Provides good compressive strength.
- Useful for repairs and anchoring.
- Works well with additives for specific applications.
Practical Tips to Choose Between Mortar and Grout
- Check the project need first – bonding or filling?
- Do not interchange them, even if the mixes look similar.
- Use proper ratios recommended by codes or manufacturers.
- Always mix small batches to avoid drying.
- Clean the surface before applying either material.
Following these tips helps achieve stronger, safer, and long-lasting construction.
FAQs
1. Can I use grout instead of mortar for brickwork?
No, grout is too flowable and cannot hold bricks in place. Mortar is the correct choice.
2. Is mortar stronger than grout?
Mortar is stronger in bonding, while grout is stronger in compressive filling.
3. Can grout crack?
Yes, grout can crack if mixed with too much water or if the surface moves.
4. What is non-shrink grout?
It is a special grout that does not shrink while setting. It is used under baseplates and machinery.
5. Can I use mortar for tile joints?
No, tile grout is specially designed to fill gaps and resist moisture.
Conclusion
The Difference Between Mortar And Grout is quite simple once you understand how each material behaves. Mortar is ideal for bonding units like bricks and blocks, while grout is perfect for filling spaces and anchoring. Because both materials play unique roles, choosing the right one ensures your structure remains strong, stable, and long-lasting.