Pointing is generally used to increase the bonding capacity and improve the appearance of mortar joints in brick and stone constructions. Keyed or grooved pointing refers to special kinds of pointing.
This technique involves pulling a jointer over the wall surface in contact with the mortar, giving the wall a concave or grooved joint to achieve better adhesion and water tightness. Keyed pointing is easily recognizable because of its decorative appearance; apart from giving the building a good outlook, it channels any water away from the joint and, therefore, avoids erosion.
Outdoor external stonework, especially those exposed to weather elements such as rain, direct sunlight, and other forms of precipitation, is common in this application since it provides considerably more lasting protection than any pointing technique.
What Is Keyed Or Grooved Pointing in Brick Masonry Construction?
Keyed or grooved pointing is used in brick masonry construction to enhance the aesthetic appeal and durability of mortar joints. This type of pointing involves pressing the mortar into a concave or grooved shape along the joints using a unique pointing tool or jointer.
Keyed or grooved pointing refers to creating a concave or indented shape in the mortar joints of brick masonry. It is known as “keyed” or “grooved“ because of the distinctive indentation (groove) formed along the joint, resembling a “key” that interlocks the mortar with the bricks.
Why is it Called “Keyed” or “Grooved”?
- Keyed Effect
- The term “keyed” comes from creating a secure, interlocking bond between the mortar and the bricks. The pressure applied during the pointing process “keys” the mortar into the joint, improving adhesion and strength.
- Grooved Appearance
- The visible groove or concave profile formed on the surface means “grooved pointing.” This shape adds a clean and decorative look to the masonry.
- Functional Grooves
- It also applies pressure to the joint surface with water, and since it prevents water from infiltrating into the groove, it becomes a protective channel of the roof. This functional benefit is one of the characteristics of grooved pointing.
What Is The Process Of Keyed or Grooved Pointing in Stone Masonry?
The process ensures both aesthetic appeal and enhanced weather resistance for stone structures. Here’s how it’s done:
Steps Involved in Keyed or Grooved Pointing
- Preparation of the Joints
- After laying the stones and allowing the mortar to set, the joints are cleaned of excess mortar, dirt, and debris.
- This ensures proper bonding of the new pointing mortar to the existing surface.
- Mortar Application
- New mortar is introduced into the ridges, which must be well swept with a stiff broom. The mortar is normally prepared to a stiff consistency so that it does not flow during the pointing process.
- Shaping the Joint
- Once the mortar is applied, a unique tool called a pointing tool, or jointer, is used to create the grooved or concave shape in the joint.
- The tool is force-applied along the joint to result in a neat, consistent groove or an impressed area in the mortar.
- Depending on the intended finish, the depth and width of the groove are then variably set.
- Finishing the Joint
- After the grooving is complete, the joint’s surface is smoothed to remove excess mortar and create a clean line.
- The edges of the joint may also be slightly chamfered to create an ornate look.
- Curing and Setting
- The mortar is left to cure and harden for a specific period. During this time, it strengthens the bond between the stone and the mortar, providing a durable and weather-resistant finish.
Benefits of Keyed or Grooved Pointing in Stone Masonry
- Enhanced Durability: The groove effectively drains water off the joint, so water cannot emanate in the stonework, leading to erosion of the structure within a short time.
- Aesthetic Appeal: An additional benefit to the grooved surface is that it provides a polished, smooth, and aesthetically pleasing outlook to stone masonry and the construction in question.
- Improved Bonding: The pointing tool’s pressing action “keys” the mortar into the joint, enhancing the bond between the stone and the mortar.
Keyed Pointing Vs. Traditional Pointing Methods
Keyed pointing involves pressing the mortar into a concave or grooved shape to improve adhesion and direct water away from the joints. Traditional pointing methods, like flush or struck pointing, typically involve smoothing the mortar level with the surface or creating a simple beveled edge without special shaping for water resistance. Keyed pointing is often preferred for its added durability and aesthetic appeal compared to traditional methods.
| Feature | Keyed Pointing | Traditional Pointing |
|---|---|---|
| Mortar Shape | Concave or grooved profile | Level or slightly beveled |
| Water Resistance | Better water shedding and protection | Moderate water resistance |
| Aesthetic Appeal | Clean, uniform, and decorative finish | Simple, may appear less defined |
| Bonding Strength | Improved interlocking with stones or bricks | Standard adhesion, may weaken over time |
| Common Use | Exterior masonry and weather-exposed walls | Interior or non-exposed masonry |
| Labor Intensity | Requires specialized tools and techniques | Easier to apply and less time-consuming |
Expert Keyed or Grooved Pointing and Brick Pointing Services by Sardar Restoration Corp
Sardar Restoration Corp stands out as the best choice for masonry repair and restoration services. It offers expertise in brick pointing, and all types of masonry pointing techniques, including tuck pointing, struck pointing, weathered pointing, flush pointing, and repointing.
Our team has many years of experience, which allows us to carry out work at a high professional level that guarantees improved durability and aesthetics in the structure of your object. We also estimate the cost of repointing the brick, giving an apparent quotation. Satisfying legal demands 11 of the local code, Sardar Restoration Corp ensures that all jobs are done safely and to the required standard.
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Wherever you are, our services are tailored to meet local needs. Contact us today at (+1) 917-355-8556 or sardarrestoration@gmail.com, or visit us at 2770 Fish Ave, Bronx, NY 10469, United States. Let us bring excellence to your next project!
FAQs
When is keyed pointing most commonly used?
Keyed pointing is most frequently used in exterior brick or stone masonry exposed to weather, providing enhanced durability and water resistance. It is also preferred for decorative finishes in structures.
How does keyed pointing improve mortar strength?
Keyed pointing improves mortar strength by pressing the mortar into a concave groove, creating a stronger bond with the stones or bricks. This interlocking effect enhances overall structural integrity.
What are the common mistakes to avoid when keyed pointing?
Common mistakes include improper mortar curing, which weakens the bond, and inconsistent joint shaping, which affects both the aesthetic and functional outcome. It’s also important to avoid overfilling the joints with excess mortar.
Is keyed pointing cost-effective for large projects?
Keyed pointing may be more labor-intensive and time-consuming than traditional methods, making it slightly less cost-effective for extensive projects. However, its durability and long-term benefits can offset these costs.
