Joint Finishes and Surface Treatments

Module 4: Joint Finishes and Surface Treatments 

This module provides Brickwork Technicians – Level 2 with essential skills in mortar preparation, joint finishing techniques, and brickwork maintenance to ensure durability, aesthetics, and weather resistance.

1. Mortar Mixing (Ratios, Consistency, Additives)

Key Components & Best Practices

• Mortar Ratios:

• 1:3 (Cement:Sand) – High-strength for load-bearing walls.

• 1:4 to 1:6 – General-purpose for brickwork and repointing.

• Lime Mortar (1:2:9 – Cement:Lime:Sand) – Flexible and breathable for historic buildings.

• Consistency:

• Should be plastic and workable (not too dry or sloppy).

• Test: Mortar should hold its shape when pressed but spread easily with a trowel.

• Additives:

• Plasticizers – Improve workability without weakening the mix.

• Waterproofers – Reduce moisture penetration (e.g., for below-ground work).

• Pigments – Color matching for repairs.

Common Mistakes:
❌ Adding too much water (weakens mortar).
❌ Inconsistent mixing (leads to poor bonding).

2. Joint Finishing Techniques

Types of Joint Finishes & Applications

• Recessed Joint:

• Mortar pressed back 5–10mm from the brick face.

• Creates shadow lines but offers less weather resistance.

• Weatherstruck (Struck & Pointed):

• Angled finish (sloped downward) to shed water.

• Requires skill with a pointing trowel.

• Flush Joint:

• Mortar smoothed level with the brick face.

• Simple but prone to weathering over time.

• Bucket Handle (Concave):

• Curved finish using a jointer tool, improves durability.

Tool Guide:
✔ Pointing trowel – For precise application.
✔ Jointing iron – For smooth, concave finishes.
✔ Stiff brush – Removes excess mortar before curing.

3. Cleaning and Protecting Brickwork

Post-Construction Care

• Cleaning Methods:

• Dry brushing – Removes loose debris before mortar fully hardens.

• Chemical cleaners – For stubborn stains (e.g., efflorescence).

• Pressure washing (low PSI) – Avoids brick surface damage.

• Protective Treatments:

• Silane/Siloxane Sealers – Water repellents that allow brick to breathe.

• Anti-Graffiti Coatings – For urban environments.

Dos & Don’ts:
✔ Clean before mortar fully cures (easier removal).
❌ Avoid acid-based cleaners on limestone or soft bricks.

4. Basic Pointing and Repairs

Step-by-Step Repointing Guide

1. Rake Out Old Mortar (10–15mm deep) – Use a raking tool or angle grinder (carefully).

2. Dampen Joints – Prevents new mortar from drying too fast.

3. Apply New Mortar – Press firmly into joints with a pointing trowel.

4. Finish Joints – Choose technique (weatherstruck, bucket handle, etc.).

5. Cure Properly – Keep moist for 48 hours to prevent cracking.

Common Repair Scenarios:

• Cracked Bricks – Replace if structural; patch with mortar if cosmetic.

• Spalling (Flaking Bricks) – Remove damaged areas and repoint.

Conclusion

This module ensures technicians can:
✓ Mix mortar correctly for strength and workability.
✓ Apply professional joint finishes for aesthetics and weatherproofing.
✓ Clean and protect brickwork to extend lifespan.
✓ Perform basic repairs to maintain structural integrity.