Different Methods of Pointing in Construction

During the construction of masonry work, whether of brick or stone, the joints near the faces of walls are frequently left rough. This is done for specialized treatment later. This also allows the masonry work to move very quickly. After the wall is completed, precise finishing of joints in a desirable manner is often required to improve the appearance of the construction.

However, the subsequent treatment at the joints, known as pointing, is mostly a structural need. It ensures long-term durability by preventing rainwater and frost from penetrating the interior of the masonry construction through the joints.

It should be noted that the joints are weak spots in the structure and should be adequately guarded from the corrosive effects of the sun, rain, and frost. The joint is generally struck as the process progresses. This is not a good method to support a clean final treatment.

Mortar Used for Pointing Work

Pointing mortar can be made of lime or cement, and it is usually richer in proportion than masonry mortar.
If lime mortar is used, it should be double-ground, meaning that it should be reground after about 10 days following the first grinding.

One part of cement to two parts of fine and clean sand (1:2) should be used for cement pointing, and one part of good well-burnt lime to one part of sharp clean sand (1:1) should be used for lime pointing. However, it should be recalled that pointing work does not persist indefinitely and must be replaced periodically by repointing.

Also Read : Different Types of Mortar Used in Construction

Procedure of Pointing Work

• When constructing a new wall, the joints should be pointed while the inner masonry work is still green.
• All of the joints on the face are raked out to a depth of about ³/₄ inch with a specific pointing tool to provide a correct and firm grip for the pointing mortar.
• To produce the appropriate adhesion, the joints and the wall surface are thoroughly wetted and cleaned with a brush.
• With a tiny trowel, the mortar is applied within the joint and pressed firmly to make a solid contact with the internal joint, leaving no hollow at the junction.
• This is critical since a loose filling will always result in the pointing pulling off at a later stage.
• Watering should be done on a regular basis to keep the work moist for roughly a week.

Different Methods or Types of Pointing

The joints are properly closed in one of the following ways.

Flush or Flat Pointing

A simple way of pointing consists of forcing the mortar into the previously opened out joint with a trowel and then removing the excess mortar beyond the face of the wall, leaving the joint flat with the face.

Struck or Weathered Pointing

This style of pointing is fairly common. Instead of keeping the face of the point upright, the top line is pressed slightly inside, causing the face of the pointing to slope outwards. This improves the effect of throwing off the rain as well as the effect in the recess left at the top.

By pressing the bottom line inside the joint, a weathered or struck pointing can be generated. This has the advantage of preventing rainwater from accumulating in the V-recess.

Recessed Pointing

Instead of being slanted, the face of the pointing is placed behind the plane of the wall and left vertical.

Keyed or Grooved Pointing

The above-mentioned flat or flushed pointing is enhanced by lines or keyed grooves made by pressing a specific instrument known as ‘Naila’. This effect is said to improve the appearance from a distance by producing artificial gloomy lines, particularly in the case of brick masonry work.

The groove on the face of grooved pointing is larger than that of keyed pointing.

Tuck Pointing

After pressing the mortar into the joint, a tiny channel or groove is cut in the mortar. The groove is then filled in with white lime putty, which is allowed to protrude ¹/₈ inch beyond the face of the joint.

V-Pointing

There are two varieties of V-pointing: one constructed by projecting the pointing face’s V-shape outside the wall face and the other by pressing the V-inside, as shown in figure.