What Is Pointing?
Pointing is the term given to the “finish” that sits between the bricks or stone used to build your home. This process is crucial in pointing in construction. Depending on the age of the building, the mortar used to deposit the stone or brick will be made of lime or, more recently, cement.
What is pointing? Pointing incorrectly causes irreparable damage to older buildings. It is essential to understand what mortar joints really do for the fabric of the home. The function of mortar on the wall is to act as a foundation between stones and varies from fine joints in the stonework to larger joints in rubble masonry walls.
The joints are effectively reduced in size by inserting small stones and ‘cut’ pieces of stone. While acting as a bed, the mortar must also perform other functions:
In the context of pointing in civil engineering, it must prevent water from penetrating through the joints due to its physical presence almost like a masonry ‘sponge’ but it must allow the wall to breathe and drain, porosity being a key factor when choosing a mortar to refer to.
It must be flexible to allow movement/settlement of the structure due to thermal responses and settlement within the structure. Many former large buildings are not designed with today’s modern expansion/contraction joints.
The strength of the mortar should always be less than that of the surrounding stones and should be considered as a sacrificial element of the wall and seen as a maintenance item that needs to be replaced, possibly every century.
The condition of the stone walls cannot be seen in isolation, and replacing any walls will not cure water ingress problems caused by other construction failures, such as gutters, roofs, and lead. They must be in good condition to maintain the useful life of the wall elements.
The walls need to breathe – and, if the indicator does not allow it, the wall will quickly deteriorate. Mortar joints are the lungs of a wall – they allow water inside the structure to enter and exit freely. If the water tries to come out through stone or brick, it will slowly disintegrate. Block the mortar joints, and the wall will be destroyed.
The mortar must be softer than the material with which the wall is constructed. The indication must be subservient to the material with which the wall is constructed and visually assume a secondary function.
Types of Pointing In Brick Construction
Pointing is the finishing of mortar joints in the construction of bricks, often referred to as pointing work. Aiming is the implementation of joints at a depth of 10 mm to 20 mm and fills it with better quality mortar in the desired shape.
It is made for cement-pointing mortar and lime mortar joints. Exposed joints are considered the weakest and most vulnerable points from which rainwater or moisture can enter.
Importance Points for Pointing In Masonry:
The following conditions have been adopted for the direction,
- Pointing work can be done with a finishing surface of the exterior brickwork using a richer mortar mixture to make the joints look better.
- Where the outer surface does not need to be made a smooth surface.
- Pointing can be a suitable option for designing surfaces in different patterns, thicknesses, colors, and joints.
- Pointing is perfect for showing the natural beauty of stone blocks and brick-like materials in the walls.
- Where pointing to stone blocks with good quality finishing materials for use in construction can be an economical option.
Mortar for Pointing Works
- 1: 2 lime mortar (1 fat lime: 2 sand)
- 1: 3 cement mortar (1 cement: 3 sand)
Surface Preparation for Aiming
All masonry joints are joined to a depth of 20 mm, while the mortar is still soft. The joints and surfaces are cleaned and then completely wet.
Pointing Methods
After preparing the surface, as mentioned above, the mortar is carefully placed on the joints using a small spatula. The mortar placed must have the desired shape.
Whenever the fresh mortar is placed on the joints, it must be pressed hard to obtain a strong connection with the old internal mortar.
Care must be taken when using first-class ashlar or masonry. Otherwise, the mortar does not cover the edges of the face. The pointed surface is kept wet for at least a week or plowed after application.
Types of Pointing:
Different types of pointing in construction are as follows.
1. Keyed Pointing
In flush pointing, the mortar is pressed on the joints joined and finished with the face of the wall. While the pressed mortar is still green, a groove is formed, passing the folded end of a small steel bar (6 mm in diameter) straight along the centerline of the joints. Vertical joints are also finished in the same way.
2. Cut Pointing
In this type of pointing, the mortar is pressed first in joints. While the mortar is still green, the top of the horizontal joints is pressed from 3 to 6 mm with the pointing tool. Thus, the joint is finished by tilting from the top of the joint to the bottom.
3. Flush Pointing
In this type, the mortar is pressed hard on the joined joints and ends flush with the edge of the masonry units. The edges are well trimmed with a spatula and a straight edge.
It doesn’t look good. However, aiming the flush is more durable because it resists the provision of space for dust, water, etc. for this reason, this method is widely used.
4. Recessed Point
In this case, the mortar is pressing 5 mm or more at the edges. During the placement of the mortar, the face of the sharpener is held vertically, using a suitable tool. This guy looks really good.
5. Beaded Pointing
Beaded pointing is formed by steel or ironed with a concave edge. It looks good but will damage easily when compared to other types.
6. Tuck Pointing
In this case, the mortar is pressed first at the anchored joint and finished with the face. While the pressed mortar is green, the channel or narrow channel is cut in the center of the channel, which is 5 mm wide and 3 mm deep.
This groove is then filled with white cement mass, projected beyond the face of the joint by 3 mm. If the projection is made in the mortar, it is called a pointing bastard or half-a-bend point.
7. V- Pointing
Weathered pointing is done by making a V-shaped projection. Weathered Pointing. This is done by making a V-shaped projection.
Mortar for Pointing:
Lime mortar or cement mortar is commonly used for pointing
Lime Mortar For Pointing:
Lime mortar for pointing is made by mixing fat lime and fine sand in a ratio of 1: 2. Mortar is a traditional method of repairing old buildings.
Cement Mortar for Pointing:
Cement mortar is prepared by mixing water in cement and sand in a ratio of 1: 3 for points. It involves mixing cement and sand in a dry manner on a tight water platform as required.
It is advisable to use a mortar prepared for good quality for pointing within 30 minutes after adding water. Usually, a bag of cement is used to prepare the mortar for pointing.
Ready Mixed Mortar for Pointing:
A ready-mixed mortar is a mixture of sand and cement in the required ratio. You can prepare the mix in the right consistency by simply adding water to it. Ready-mixed mortar can use ready-mixed mortar with high strength in less time.
Purpose of Pointing:
- Pointing work only protects the mortar joints in brickwork from the adverse effects of the environment. Different types of pointing work make the pattern, thickness, and texture of the joints in the brickwork clearly look beautiful on the wall.
- Externally exposed masonry joints are considered to be the weakest and most vulnerable. Pointing is appropriate to prevent rainwater or moisture from entering and damaging the brickwork.
- Pointing work strengthens joints by sealing gaps or spaces in mortar.
- Sometimes pointing work can be done aesthetically for decorative purposes
- It provides strong and reliable bonding against the external environment in brick/stone masonry joints.
FAQ:Pointing in Brick and Stone Masonry
What is pointing in masonry?
Pointing refers to the finishing of mortar joints in brick or stone masonry. It involves applying mortar to the visible joints between bricks or stones to improve the appearance, durability, and weather resistance of the wall.
Why is pointing important in construction?
Pointing is crucial because it helps prevent water ingress, allows the wall to breathe, and accommodates structural movement. It also enhances the aesthetic appeal of the masonry and prolongs its lifespan.
What materials are used for pointing?
Common materials used for pointing include lime mortar (a mix of fat lime and sand) and cement mortar (a mix of cement and sand). Ready-mixed mortar, which is a pre-mixed combination of sand and cement, can also be used for convenience.
What are the different types of pointing?
- Keyed Pointing: Features a groove formed by pressing a steel bar along the joints.
- Cut Pointing: Involves pressing the mortar and then cutting the top of the horizontal joints.
- Flush Pointing: Mortar is pressed flush with the masonry units.
- Recessed Pointing: Mortar is pressed back 5 mm or more from the edges.
- Beaded Pointing: Forms a concave edge with a steel tool.
- Tuck Pointing: Involves creating a channel filled with white cement for decorative purposes.
- V-Pointing: Features a V-shaped projection for enhanced durability.
How is the surface prepared for pointing?
The masonry joints are raked out to a depth of 20 mm while the mortar is still soft. The joints and surfaces are then cleaned and thoroughly wetted before applying the new mortar.
What is the purpose of pointing in brick and stone masonry?
Pointing serves to protect mortar joints from environmental damage, prevent water penetration, strengthen the joints, and enhance the wall’s aesthetic appearance. It also helps maintain the wall’s structural integrity by allowing for proper drainage and movement.
How often should pointing be replaced?
The mortar in pointing is designed to be a sacrificial element of the wall, typically needing replacement every century, depending on the environmental conditions and the quality of the initial work.
Can improper pointing cause damage to buildings?
Yes, incorrect pointing can lead to irreparable damage, especially in older buildings. Using the wrong type of mortar or improper application can block the wall’s ability to breathe, leading to trapped moisture and eventual deterioration of the masonry.
What is the difference between lime mortar and cement mortar for pointing?
- Lime Mortar: Made from fat lime and sand, traditionally used in older buildings, and allows the wall to breathe.
- Cement Mortar: Made from cement and sand, providing higher strength and quicker setting times, but less breathability compared to lime mortar.
What is the role of pointing in aesthetic enhancement?
Pointing can enhance the visual appeal of a wall by highlighting the natural beauty of the masonry units and allowing for various decorative patterns, colors, and textures in the joints.
