The finishing of mortar joints in stone or brick masonry is referred to in the building industry as “pointing.” The seams close to the faces of walls are left rough throughout the building of masonry work, whether it be made of brick or stone. This is performed as a special treatment at a later stage of Brick masonry. As a result, the masonry work may go extremely fast. To enhance the construction’s look when the wall is finished, careful finishing of joints in a desirable manner is sometimes needed. Pointing is the practice of using lime mortar or cement mortar to finish the joints in walls or other comparable constructions. Stone masonry is most suited for pointing because of the stones’ appealing colours and strong resistance against water infiltration. Pointing enhances the visual appeal of the brickwork by giving perfection to the weaker, or joint-related, portion of the structure. By preventing precipitation and ice from entering the inside of the masonry structure through the joints, pointing promotes long-term durability and shields the joints from atmospheric agents. Typically, a full wall or even a whole structure is indicated since damaged locations might be difficult to discover and adjacent joints may need to be fixed. Since pointing is far more affordable than plaster, it can be used to finish an outside surface where cement is being stored. Water cannot enter the wall when pointed correctly. Older structures may sustain permanent harm from incorrect pointing. Understanding what mortar joints actually accomplish for the fabric of the building or wall is crucial. Mortar is used on walls to fill in the spaces between stones and serves a variety of purposes, from small joints in stonework to larger joints in rubble masonry walls and joints. When the mortar is still green, this method works best to apply. The raked joints must be thoroughly cleaned to remove any dirt and dust. Before the procedure starts, the joints and the walls are thoroughly cleaned and kept moist for a significant amount of time. The way the mortar is rendered relies on the design; it can be flushed, sunk, elevated, etc., depending on what you want for your facade.
History of Pointing
Within a wall, pointing has a functional (protective) and decorative purpose. Pointing towards monuments has historical and documentary importance as well. In light of a restoration, its worth and relevance need to be explained. Romans established the foundations of pointing method and spread it across their empire. The solid tradition they maintained began to change and eventually vanished during the challenging years that followed the fall of the Roman Empire. The construction methods utilised, the materials used, the expertise of the masons, the significance and location of the structure, and the composition of the materials all had a significant impact on the quality of the pointing/tooled bedded mortar across time and space. The development of brick including its fabrication or format or quality and the tooled bedded mortar pointing have a definite link. This might be done to address the irregularity of the bricks, achieve unusual effects, or even draw attention to the masonry’s straightness. Sometimes the pointing in excessively broad joints was painted the same colour as the brick, and false joints were created in a predictable manner before being eventually filled with mortar. Aesthetic considerations also went into the colour of the pointing and the tooled bedding mortar. When uniformity was desired, it may resemble that of brick stone, or it might contrast with that of the stony elements, creating an obvious pattern. Because lime mortars made up the majority of historic mortars, pointing mortar was finer and less porous than bedding mortar. Gypsum lime mortars, or “trabadillos,” were commonly employed in the Iberian Peninsula, and in Italy, gypsum was utilised in areas where it was available, either alone or in conjunction with lime. All of the nations utilised hydraulic mortars, hydrated lime, sand, and additives. In the Netherlands, shells were used in addition to stone to produce lime.
Scope of Pointing
• By highlighting the pattern of the joint, colours, their thickness, and texture vividly, the pointing work not only shields the mortar joints from the damaging effects of the environment but also enhances the aesthetic of the wall.
• It keeps structural joints in good condition.
• It should be used because of its affordability and suitability for areas with little rainfall.
• It drains rainwater readily from the joint of the masonry, providing resilience to weather conditions for the bricks and stones used in building.
• Pointing finishes offer surfaces a protective covering that shields the materials used in buildings from environmental factors including heat, cold, and moisture. Additionally, it offers aesthetic finishes or effects that improve the overall look of the structure and its material surfaces. For exposed brick and stone walls, primarily. For areas where the intensity of the rainfall is great, it is not advised.
• In the case of externally exposed masonry construction, the joint is recognised as the weakest and most vulnerable locations from which rainfall or moisture might enter. It is an economical solution since it avoids the expense of both plaster and paint.
• The main goal of pointing is to keep the structures’ joints in good condition. Low-rainfall areas can use pointing because it is inexpensive. The pointing of the bricks and stones used in construction gives them resistance to the elements.
• Because it can be challenging to identify problematic points and nearby joints may also need to be repaired, pointing is frequently performed on a whole wall or complete building. Up to a depth of 10 to 20 mm, it is completed.
Pointing is reinstated where:
• A smooth and uniform surface is not required;
• The natural beauty of building materials, such as stone blocks, bricks, etc., is to be displayed.
• Where the craftsmanship is pretty good;
• Where the building materials can endure the impacts of weather.
The importance of pointing
• It aids in sealing any gaps or holes that might harbour water and contribute to the mortar in joints deteriorating.
- Properly and tastefully done pointing work will help eventually reduce regular maintenance.
• It provides a strong and dependable bond finish at the brick/stone masonry joints.
• It is applicable in many locations, including in low-precipitation regions.
Uses of Pointing
• Cement mortar may be used to fill in the gaps at brickwork wall seams.
• Cracks in the buildings can be maintained and repaired by repointing.
•Stones can be used for pointing in stone masonry to strengthen and stabilise the structure, and occasionally individuals point their buildings only for aesthetic reasons.
Types of Pointing
- Flush Pointing
The mortar was poured and forced into a mortar joint during flush pointing. To give it a smooth appearance, it is then finished flush with the edges of the bricks or stones. The edges are then precisely trimmed with a trowel and straight edge to provide the final polish.
• Flush pointing can also be accomplished by lightly rubbing a piece of rough cloth or a trowel over the completed pointing.
•Although it doesn’t look beautiful, it is resilient because it prevents the buildup of dust, water, and other elements.
•It is one of the most often used forms of pointing in building construction and is appropriate for both brick and stone masonry.
• To prepare the surface of the joint for troweling, the raked area is filled with mortar and made flush with the brickwork.
- Weathered Pointing
• With Aged Using the pointing tool, the top of the horizontal joints is carefully pulled back by 3-6 mm after the mortar has been pressed into a joint and while the mortar is still fresh. From the top to the bottom of the joint, they appear to be sloping.
• This sort of joint provides appropriate defence against weathering, as the name implies. However, a considerable amount of water is needed.
- Keyed Pointing
The mortar in these Keyed varieties of pointing is troweled into the joints and well completed with the brickwork surface. The joint is then longitudinally pressed back by small-diameter steel after that (6 mm diameter). It will create a mortar joint with a curved arc groove. Similar finishes are also used for the vertical junction.
In this style, joints are initially filled with mortar.
• A tool or tiny steel bar is used to create a semi-circular curve type notch.
• These pointing techniques give the wall a beautiful aspect.
• Keyed pointing is typically utilised for better type work, especially for vertical wall joints.
• The pointing creates a classy appearance.
- V-grooved Pointing (V Pointing)
Keyed pointing work is analogous to v-grooved pointing, or “V pointing.” A joint was filled and shoved into the mortar.
•The V-shaped groove is then created in the joint using a V-shaped tool, which gives it its name.
•It is appropriate for masonry work of types rubble and ashlar.
- Beaded Pointing
• The mortar is forced into the raking joints and completed flush with the face of the wall in this kind of pointing. A steel rod with a suitably formed end is run straight down the centre line of the joints while the pressed mortar is still liquid to create the beading.
• When beaded pointing is used, a steel tool with a concave shape is used to force mortar into a masonry joint and create a junction. Although it offers the mortar joint a beautiful look, beaded pointing is easily destroyed.
• In contrast to other varieties, it has a good appearance but is fragile and quickly destroyed.
- Struck Pointing
• In this pointing, the top edge of the joint is driven inside about 10 mm more than the bottom corner after the mortar has been filled and pressed to meet the face of the brick masonry work. It will take the shape of a slope from top to bottom so that the rain wall will swiftly drain off.
• The lower section of the pointing is flush with the brickwork, while the higher portion is 12 mm within the masonry face.
- Recessed Pointing
Since they do not readily shed water, these forms of pointing are typically not ideal for structures in exposed conditions.
• Recessed pointing is achieved by pushing mortar 5 millimetres or more away from edges.
• The face that is pressing is kept upright.
• Bricks with exceptional frost resistance should only be used with recessed joints, it is advised.
• It has a pleasing look.
• It is employed for fine masonry work.
- Tuck Pointing
• The mortar joint is filled and forced to the level surface of the brickwork in various methods of pointing.
• Grooves are carved into the mortar joint while the mortar is still new. 5 mm wide by 3 mm deep is the size of the slot. This was then filled with white cement putty and continued to extend 3 mm beyond the joint face. If these projections are made using a mortar, the technique is known as half-tuck pointing or bastard pointing.
• The mortar is initially forced into the raking joints in this kind of pointing before being completed flush with the face of the wall. The top and bottom borders of the joints are cut parallel while the pressed mortar is still green to create a consistently elevated band that is about 6 mm high and 10 mm wide.
• The look of this pointing is appealing.
- Cement Pointing
Pointing is a technique for re-mortaring brick or stone masonry joints. The area is filled with the same amount or a rich proportion of mortar in the appropriate shape after raking out the previous joints’ mortar 13 to 20 mm deep. Since it is long-lasting and sturdy, cement mortar pointing is often the most preferred.
Mortars used in Pointing
1. Lime Mortar
To make lime mortar, combine fat lime, fine sand, and water in the proper ratios. For pointing operations, lime mortar with a ratio of 1:2 or 1:3 is typically employed.
It is employed to indicate:
• Modern and traditional construction techniques for new structures
• Old structures
2. Cement Mortar
• To make cement mortar, combine the necessary amounts of cement, sand, and water. At most cases, pointing work involves the use of cement mortar in a 1:3 ratio. To prevent the mortar from hardening too soon, use the prepared mortar within 30 minutes of preparing it.
• Both new and ancient structures employ it when they are pointed.
3. Surkhi Mortar
• Surkhi mortar is made by combining water, lime, and surkhi in the right amounts. Surkhi mortar with a ratio of 1:2 is typically used for pointing operations.
• Older buildings and constructions are typically pointed with it.
PRECAUTIONS FOR POINTING
• The mortar you use should be new.
• Before beginning the pointing process in older structures or buildings, the joints should be well moistened as mortar may not adhere to a dry surface.
• The type of mortar and pointing should be selected according on the needs of the project.
• Pointing work shouldn’t be done in cold weather since it might cause joints to disintegrate as a result of freezing.
Method of Pointing
Lime or cement can be used to make the mortar used for pointing. Traditional construction materials like lime mortar are still used today, but primarily for restoration and repair work. Typically, lime mortar is created by combining lime and sand in a 1:3 ratio, and it then carbonates to set. Calcium hydroxide from the hydrate lime in the mortar mixes with carbon dioxide in the air to generate calcium carbonate during the carbonation of lime mortar. Pozzolans, a large class of siliceous and aluminous materials, were used to increase strength. Examples include volcanic ash or pulverised clay bricks and tiles. Mortar for pointing should have a greater ratio than mortar for brickwork. After the initial grinding, or “double grinding,” which normally takes place after approximately 10 days, lime mortar should be reground. If cement mortar is utilised, a ratio of one part cement to three parts fine, clean sand, or 1:3, should be employed. For lime pointing, however, it is recommended to employ a ratio of 1:2 (excellent, well-burnt lime to sharp, clean sand or surkhi). However, because pointing work is temporary, it needs to be changed on a regular basis. Repointing is the practise of renewing pointing. Lime mortar repointing has a number of advantages over utilising other types of mortar to repair damaged mortar joints. Flexibility and softer mortars are the main arguments in favour of using lime mortar for pointing.
Whether it be brick or stone masonry, the mortar joints are chiselled away as part of the pointing process. The area is filled with the proper mortar in the desired form. Cement mortar is frequently used for pointing because of its weather-required durability.
Refer below procedure for pointing,
• To expose the rough mortar surface while the mortar is still soft, all masonry joints should be racked out to a depth of 15 to 20 mm.
• To achieve the proper adhesion, the surface should be properly wetted and scrubbed with a brush using either water or cement slurry.
• Produce the necessary adjustments to the mortar’s proportions, fill the exposed joints with a small trowel, push down hard to make a strong contact with the internal joint, and leave no hollows where the joints meet. This is important since a loose filling will always cause the pointing to come off later on. When placing new mortar in joints, it should be lightly squeezed to form a firm connection with the existing internal mortar.
• If ashlar or first-rate brick work is used, care must be taken to ensure that the mortar covers the face edges.
• Use the plastering channel to carve or groove the surface as desired or appropriate for pointing (Aluminium Patti)
• By scraping them, you may get rid of the extra material.
• Regular watering and curing are necessary to keep the artwork wet for 7–10 days.
Advantages for Pointing
• It enhances the building’s overall appearance.
• It lessens the need for additional maintenance or restoration work.
• Additionally shields the building’s walls from bad weather.
• It increases the building’s structural stability.
• Prevents water damage to exterior walls
• It prevents joints from breaking and shrinking.
• It offers some protection against weathering for bricks and stones used in brickwork.
• If there are any defects in the stone masonry, they may be maintained and repaired by tuckpointing with mortar that contains Portland cement.
• There are gaps or voids between brick or stone masonry that can be filled up with pointing work to prevent water from entering.
• The thermal properties of a wall can be preserved by filling any voids with insulation during repointing operations.
• Repointing enhances finishing by integrating structural components with brickwork.
• It lessens the brick wall’s potential for additional deterioration.
• Less mortar made of cement is needed. restores the strength and longevity of old masonry structures by mending their broken joints.
• Ponting provides the surface of the wall and the structure an attractive appearance.
• Repointing can be done at a later time by removing the previous one to alter the appearance of the architecture.
• Pointing minimises the need for continuous brickwork maintenance.
• It raises the property’s worth.
• It reduces the cost of the plastering process.
• Improved joint finishing
• Strength and colour consistency
• Better joint finishing selection
• Face-cleaning tasks
• Structural advantages: When completely dampened before laying or pointing, the bricks absorb moisture from the mortar. It causes a partial dehydration of the joint toward the joint face along with evaporation. Therefore, the jointing tool’s function is to reinforce the surface of the joints, repairing shrinkage cracks and protecting against the entry of driving rain.
Dis-advantages for Pointing
• It only works well for joint fillings.
• The inside of the walls cannot be affected.
• If done improperly, it does not produce a smooth and plain aesthetic aspect.
• Even after pointing, brick/stone masonry may still include flaws.
• Areas with frequent rains cannot be used for this.
• On masonry with fissures, improper seating of the pointing may produce a spider web look.
• Masonry pointing made of bricks or stone might be challenging to paint.
• Moist brickwork freezes and rots over the winter.
• Bricks or stones that are crumbling start to appear.
• It caused serious damage to a number of walls.
• Increased labour and supply prices
• Extended construction period
• The compound joint cannot be connected if poorly done.
• The need for knowledgeable and experienced pointers.
Joints in brick and stone masonry are weak and most prone to damage where moisture can enter. Pointing is the process of implementing joints to a depth of 10 to 20 mm and filling them with superior mortar in the appropriate form. In order to establish the homogeneity of the blockwork, a tiny line is drawn at the joints and a little wooden scale or thickness of 5 mm is often placed on the mortar. Work on pointing should be done appropriately. Expert jointers should carefully complete the re-pointing. The existing materials should not be visually or technically damaged during clearing operations. The masonry components and their connection shouldn’t be changed, such as by enlarging the joints.