Toothing in brick masonry is a bonding technique used to connect new brickwork with existing or future brickwork by leaving alternate bricks projecting or recessed at the wall end. This creates a toothed edge that helps the next section interlock better with the old wall. It is commonly used in wall extensions, staged construction, junctions, and repair work. However, proper workmanship, mortar quality, alignment, and bonding are essential for strength. This blog explains the meaning, uses, method, advantages, limitations, alternatives, and quality checks for toothing in brick masonry.
Quick Summary
Toothing in brick masonry is the practice of leaving alternate courses of bricks projected or recessed at the end of a wall so another wall section can be bonded later. It improves interlocking between old and new masonry, but it must be done with correct alignment, mortar, curing, and structural guidance.
What Is Toothing in Brick Masonry?
Toothing in brick masonry is a construction technique where alternate bricks are left projecting or recessed at the end of a wall. This creates a toothed pattern that allows another wall or extension to be joined later.
It is usually done when construction is stopped temporarily or when a wall is expected to be extended in the future. Instead of ending the wall with a straight vertical joint, the mason leaves a stepped or toothed edge.
When the next section is built, bricks are inserted into the recessed spaces. This improves interlocking and helps the new wall connect more effectively with the old wall.
Why Is Toothing Used in Brick Masonry?
Toothing is used to create a better connection between two stages of masonry work. A straight vertical joint can become a weak line if the new work is simply placed against the old wall. Toothing reduces this weakness by creating a mechanical bond.
Common reasons for using toothing include:
- Connecting a new wall to an existing wall
- Extending brick masonry later
- Joining partition walls
- Continuing work after a construction break
- Repairing or rebuilding part of a wall
- Creating better interlocking at wall junctions
- Avoiding weak vertical joints
The main aim is to improve continuity between old and new brickwork.
Where Is Toothing Commonly Used?
Toothing is used in both residential and commercial masonry work. It is most common where brickwork is built in phases or where future wall connections are expected.
Wall Extensions
If a house or compound wall may be extended later, toothing can be left at the end of the existing wall. This makes the later extension easier to bond.
Junctions Between Walls
At some wall junctions, toothing helps connect cross walls or partition walls with main walls. It improves interlocking and reduces the risk of separation.
Repair Work
During masonry repair, damaged bricks may be removed in a toothed pattern so the replacement brickwork can bond better with the old wall.
Staged Construction
In large projects, masonry may not be completed in one continuous operation. Toothing helps maintain bonding where work resumes later.
How Toothing in Brick Masonry Works
In toothing, the end of the wall is not built as one straight vertical line. Instead, alternate courses are left longer or shorter. This creates projections and gaps.
When new brickwork begins later, the mason lays bricks into these gaps using fresh mortar. The new and old sections then interlock more effectively.
The strength of toothing depends on:
- Correct brick arrangement
- Proper bond pattern
- Good mortar filling
- Clean old surface before joining
- Accurate alignment
- Adequate curing
- Quality of bricks and mortar
If the gaps are dusty, dry, or poorly filled with mortar, the bond can become weak.
Step-by-Step Method of Toothing in Brick Masonry
The exact method depends on wall thickness, bond type, and project requirements. A general method is given below.
Step 1: Plan the Wall Junction
Before starting masonry, identify where future wall extension or connection is required. The toothing position should match the wall layout and structural drawings.
Step 2: Maintain the Bond Pattern
Lay the bricks according to the required masonry bond. Common bonds include stretcher bond, header bond, and English bond. The toothing should not disturb the overall bond pattern.
Step 3: Leave Alternate Courses Projecting
At the wall end, leave alternate courses projecting while other courses are recessed. This creates the toothed edge.
Step 4: Keep the Edge Clean
The toothed surface should be kept clean and free from loose mortar, dust, and debris. Dirty surfaces reduce bonding when new brickwork is added.
Step 5: Wet the Existing Surface
Before joining new masonry, lightly wet the old brick surface. This prevents the old masonry from absorbing water too quickly from fresh mortar.
Step 6: Fill Mortar Properly
When new bricks are inserted into the toothed spaces, all vertical and horizontal joints should be fully filled with mortar. Empty joints weaken the wall.
Step 7: Check Alignment and Level
The new wall section should match the old wall in line, level, thickness, and plumb. Poor alignment can create cracks and uneven load transfer.
Step 8: Cure the Masonry
After construction, proper curing is necessary. Mortar needs moisture to gain strength and bond properly with the bricks.
Advantages of Toothing in Brick Masonry
Toothing offers practical benefits when done correctly.
Better Bonding
The main advantage is improved bonding between old and new brickwork. The toothed pattern allows the new wall to interlock with the existing wall.
Reduced Weak Vertical Joints
A straight joint between old and new brickwork can become a weak plane. Toothing breaks this straight joint and improves continuity.
Useful for Future Extensions
Toothing is helpful when a wall is expected to be extended later. It prepares the existing masonry for a better future connection.
Better Load Transfer
A properly toothed joint can help distribute forces better than a simple butt joint. This is useful in masonry walls that need continuity.
Helpful in Repairs
In repair work, removing bricks in a toothed pattern helps the replacement area blend better with the existing wall.
Limitations of Toothing in Brick Masonry
Toothing is useful, but it is not suitable for every condition.
Needs Skilled Workmanship
Poorly made teeth can create weak joints. The mason must maintain correct bond, alignment, and mortar filling.
Not Always Ideal for Structural Walls
For major load-bearing or structural walls, toothing alone may not be enough. Engineering guidance may be needed, especially for old buildings or heavy loads.
Can Weaken Edge if Left Exposed
If toothed brickwork remains exposed for a long time, the projecting bricks may get damaged. Rain, dust, and impact can weaken the edge before the next work starts.
Poor Bond if Surface Is Not Prepared
If old mortar is dry, dirty, loose, or dusty, the new work may not bond well. Surface preparation is essential.
May Not Suit Modern Reinforced Masonry
In some cases, wall ties, reinforcement bars, or mechanical connectors may be better than traditional toothing.
Toothing vs Raking Back in Brick Masonry
Toothing and raking back are both used when masonry work is stopped or continued later, but they are different.
|
Factor |
Toothing |
Raking Back |
|
Shape |
Alternate projecting and recessed bricks |
Stepped sloping end |
|
Main use |
Future wall connection or extension |
Temporary stoppage in masonry |
|
Bond quality |
Good if done carefully |
Usually considered better for continuation |
|
Workmanship need |
High |
Moderate to high |
|
Risk |
Projecting bricks may get damaged |
More stable exposed end |
|
Common use |
Junctions and extensions |
Continuing wall length later |
Raking back is often preferred when a wall is temporarily stopped and later continued in the same line. Toothing is more common where another wall or extension is to be connected.
Toothing vs Straight Joint
A straight joint is easier to build, but it is usually weaker than a properly bonded connection. If new brickwork is simply built against an existing straight wall, the two parts may not act together.
Toothing improves the connection by allowing physical interlocking. However, it must still be supported by proper mortar, curing, and alignment.
For important walls, straight joints should be avoided unless approved details such as wall ties, dowels, or reinforcement are provided.
Good Practices for Toothing in Brick Masonry
Good workmanship is essential for durable brickwork.
Follow these practices:
- Use good-quality bricks with uniform size.
- Maintain the correct bond pattern.
- Avoid broken or weak bricks at toothed edges.
- Keep vertical and horizontal joints filled.
- Clean old mortar before joining new work.
- Wet the old surface before adding fresh mortar.
- Maintain proper wall line and level.
- Cure the masonry after construction.
- Protect exposed toothed edges from damage.
- Follow structural drawings for load-bearing walls.
These steps help improve the performance of the masonry joint.
Common Mistakes to Avoid
Many masonry defects occur because toothing is done casually. Avoid these mistakes:
- Leaving random projections without a proper bond
- Using weak or broken bricks at the joint
- Not filling mortar inside toothed gaps
- Joining new work to a dry and dusty surface
- Ignoring wall alignment
- Leaving the toothed edge exposed for too long
- Using different brick sizes without adjustment
- Skipping curing after joining
- Using toothing where reinforcement is required
- Treating non-structural details as structural support
A toothed joint is only as strong as the workmanship behind it.
Is Toothing Suitable for Load-Bearing Walls?
Toothing may be used in load-bearing masonry only when it is part of a properly planned wall connection. However, load-bearing walls need careful design because they carry vertical loads from slabs, beams, or upper floors.
If a new wall is being connected to an old load-bearing wall, a structural engineer should check the wall condition, foundation, load path, crack history, and connection method. In some cases, wall ties, reinforcement, dowels, or RCC elements may be needed.
Never depend on toothing alone for major structural changes without technical review.
Toothing in Brick Wall Extensions
Wall extensions are one of the most common uses of toothing. If a boundary wall, partition wall, or house wall is planned for future extension, toothing can make the connection more stable.
Before extending the wall, inspect the old toothed edge. Remove loose mortar, damaged bricks, dust, and vegetation. Wet the surface before laying new bricks. Use matching bricks and mortar as far as possible for better bonding and appearance.
If the old wall has cracks or settlement, repair the problem before extension.
Quality Checks for Toothing Work
Before accepting toothing work, check the following:
- Teeth are formed in alternate courses.
- Bond pattern is maintained.
- Bricks are not broken or loose.
- Mortar joints are fully filled.
- Wall is plumb and straight.
- New and old wall thickness matches.
- Joint is properly cleaned before extension.
- Curing is done after new masonry.
- Exposed toothed edge is protected.
These checks are simple but important for masonry quality.
When Should Toothing Be Avoided?
Toothing should be avoided when the wall needs a highly engineered structural connection, when the existing wall is weak, when the wall is exposed to heavy lateral loads, or when the joint will remain open for a long time without protection.
It may also be avoided in modern construction where wall ties, anchor bars, reinforcement mesh, or RCC bands are specified. In such cases, the approved construction detail should be followed instead of traditional masonry toothing.
Conclusion
Toothing in brick masonry is a useful technique for joining new brickwork with existing or future masonry. It creates a toothed edge that improves interlocking and reduces weak straight joints. It is commonly used in wall extensions, junctions, staged construction, and repairs. However, its strength depends on skilled workmanship, clean surfaces, proper mortar filling, alignment, and curing. For load-bearing or structural walls, toothing should be used only with proper technical guidance.
FAQs
- What is toothing in brick masonry?
Toothing in brick masonry is a method of leaving alternate bricks projecting or recessed at the end of a wall. This creates a toothed edge so new brickwork can be bonded later. It helps improve interlocking between old and new masonry. - Why is toothing used in brickwork?
Toothing is used to connect future or new brickwork with existing masonry. It reduces weak straight joints and improves bonding at wall extensions, junctions, staged construction points, and repair areas. Proper mortar filling and curing are essential for strength. - Where is toothing commonly used?
Toothing is commonly used in wall extensions, partition wall connections, junctions, boundary wall extensions, and masonry repairs. It is also used when brickwork is built in phases and another section must be joined later. - Is toothing stronger than a straight joint?
Yes, proper toothing is generally stronger than a simple straight joint because it creates physical interlocking between old and new brickwork. A straight joint can become a weak vertical plane if no wall ties or bonding details are provided. - What is the difference between toothing and raking back?
Toothing leaves alternate bricks projecting and recessed, while raking back creates a stepped sloping end. Raking back is often preferred when a wall will be continued in the same line. Toothing is useful for wall extensions and junction connections. - Can toothing be used in load-bearing walls?
Toothing can be used in load-bearing walls only when it is properly planned and structurally suitable. For major load-bearing connections, an engineer should check the wall, foundation, load path, and connection method before construction. - What are the disadvantages of toothing?
The main disadvantages are dependence on skilled workmanship, possible damage to exposed projecting bricks, and weak bonding if joints are not cleaned or filled properly. It may also be unsuitable for structural connections that require reinforcement or anchors. - How can toothing quality be checked?
Check that alternate courses are properly toothed, bricks are sound, mortar joints are fully filled, alignment is correct, and the surface is clean before new work starts. After joining, the masonry should be cured properly to develop bond strength.
Sowjanya Siddanoor