Comparing Masonry Jointers

Masonry jointers are used to finish brick and stonework, creating visual harmony and weather resistance. These specialized instruments come in various shapes and sizes, each designed to produce a specific joint profile. In this video, Ask This Old House expert mason Mark McCullough explains different types of jointers and their applications to host Kevin O’Connor.

Understanding Masonry Jointers

Masonry jointers shape and smooth the mortar between bricks or stones, known as “jointing” or “pointing.” This finishing touch enhances the appearance of masonry work and plays an important role in weatherproofing the structure.

Purpose of Jointing

Jointing serves three primary purposes:

1. Aesthetics: It creates a clean, finished look for the masonry work.
2. Weather protection: Properly jointed mortar helps seal the masonry against moisture infiltration.
3. Structural integrity: Well-finished joints contribute to the overall strength of the wall.

Types of Joints

Specific jointers create several types of masonry joints:

• Concave
• Convex
• Flat (or flush)
• V-shaped
• Grapevine
• Weathered
• Raked

The choice of a joint profile depends on regional preferences, climate considerations, and aesthetic desires.

Importance of Jointing in Masonry Work

Jointing is not merely a finishing touch. It enhances the masonry’s lifespan by preventing water penetration, a significant cause of deterioration. By sealing the mortar joints, jointers help the structure can withstand varying weather conditions. In addition, specific joint profiles can accommodate the expansion and contraction of materials, preventing cracks and other damage.

Common Types of Masonry Jointers

Let’s explore some of the most frequently used masonry jointers and their applications.

Convex Jointer

Despite its name, the convex jointer creates a concave joint profile in mortar and is a popular choice, particularly in New England. It is highly effective for weatherproofing, as the concave shape helps shed water, making it ideal for regions with freeze-thaw cycles.

The convex jointer is important for maintaining the structural integrity of masonry in areas prone to extreme weather changes. Facilitating water runoff helps to thwart potential freeze-thaw damage, which often compromises mortar’s durability.

Flat Jointer

A flat jointer is versatile and widely used nationwide. It creates a smooth, flat surface on the mortar joint.

In the video, McCullough shares an interesting technique with the flat jointer. By holding it at an angle, he creates a slight slope that helps water run off the joint onto the brick face below, reducing the risk of water penetration.

Grapevine Jointer

The grapevine jointer, commonly used in Pennsylvania and the mid-Atlantic region, creates a distinctive groove in the mortar, leaving a small raised bead in the center of the joint. This tool adds visual interest to masonry work and is popular in specific regional styles, enhancing the structure’s decorative appeal.

Grapevine jointing is more than an aesthetic choice; it provides a textured grip, which can help the mortar adhere better to the brickwork, adding to the structural stability.

Specialized Masonry Jointers

For specific applications or unique joint profiles, masons turn to specialized jointers.

Rat’s Tail Jointer

Despite its name, the rat’s tail jointer is a versatile tool useful for stonework. Its tapered shape allows it to adapt to different joint sizes, making it ideal for irregular masonry patterns. The tool can create narrow and wide joints by using different parts of its tapered design, offering flexibility for various masonry projects.

The rat’s tail jointer’s flexibility is invaluable for intricate stonework, where joints may vary significantly in width. Its utility extends to repair work, where existing structures present irregular gaps that must be seamlessly filled.

Skate Jointer

The skate jointer is a versatile tool designed for creating consistent and clean joints across extended sections of masonry. Its key feature is an adjustable masonry nail determining the joint’s depth. 

The tool operates in two simple steps: first, the nail is dragged along the mortar, establishing a uniform depth; then, the tool is flipped over, and its smooth end is used to finish the joint, resulting in a professional and polished appearance. This efficient process provides high-quality joints over long stretches of masonry work.

This two-step process results in a crisp, professional-looking joint with minimal effort. The skate jointer’s precision makes it an excellent choice for large projects requiring uniformity.

Concave Jointer

The concave jointer creates a rounded, outward-curving joint, exposing more of the mortar surface than a convex jointer. This style is more commonly used in warmer climates, particularly in southern regions where freeze-thaw cycles are less concerned.

The concave jointer’s ability to expose more mortar in milder climates can enhance the wall’s aesthetic appeal without compromising its integrity. The joints created with this tool are also easier to clean, providing a neat finish.

V-Shaped Jointer

The V-shaped jointer is a specialized tool designed to create pointed joints resembling the letter “V,” offering a more angular finish when desired. This tool is particularly effective in producing sharp, angular joints while efficiently removing excess mortar. Its unique design makes it ideal for use in decorative and modern architectural projects, where distinctive joint profiles are sought to enhance the overall aesthetic appeal of the masonry work.

This tool is particularly useful in decorative masonry, where precision and clean lines are necessary. Its ability to create a distinct visual appearance makes it popular in modern architectural designs.

Choosing the Right Jointer

The best masonry jointer for the job depends on various factors, such as:

• Regional climate: Areas with harsh winters often prefer joints that shed water effectively.
• Aesthetic preferences: Different joint profiles can significantly impact the overall look of the masonry.
• Type of masonry: Some jointers work better with specific types of brick or stone.
• Local building traditions: Certain regions have traditional joint styles that are commonly used.

The type of construction project may also influence your choice of jointer. For instance, residential buildings may prioritize aesthetic appeal, while commercial projects may focus on durability and ease of maintenance. It’s also vital to consider the mason’s skill level, as some jointers require more expertise to use effectively.

Proper Jointing Technique

The proper technique is necessary for a professional finish regardless of the jointer.

1. Timing: Joint the mortar when it’s firm but still pliable.
2. Consistency: Maintain consistent pressure and angle while jointing.
3. Cleaning: Brush away excess mortar after jointing for a clean look.

Steps To Achieving Perfect Joints

Achieving perfect joints involves more than just the right tools. Here are some important steps:

1. Preparation: Make sure the surface is clean and free from debris.
2. Application: Apply mortar evenly, ensuring it fills the joints.
3. Tool selection: Choose the right jointer based on the joint profile you aim to achieve.
4. Jointing technique: Use steady, even strokes to create uniform joints.
5. Final touches: Inspect the joints and make necessary adjustments for a polished finish.

Regional Variations in Jointing Styles

Jointing styles often vary by region, influenced by local climate, building traditions, and aesthetic preferences.

• New England: Favors convex jointers for better weatherproofing.
• Mid-Atlantic: Often uses grapevine jointers for decorative effect.
• Southern states: More likely to use concave jointers due to milder climate.

Understanding these regional differences helps appreciate local architectural styles and choose appropriate jointing techniques for restoration projects.

Impact of Climate on Jointing

Regional climate significantly impacts jointing styles. For instance, jointers facilitating water runoff are preferred in areas prone to heavy rainfall. In contrast, regions with stable climates prioritize decorative joints that add to the building’s visual appeal.

Cultural Influences on Jointing

Local traditions and cultural influences also shape jointing practices. Historical architecture in certain regions may dictate the use of specific joint profiles to maintain aesthetic consistency. Awareness of these cultural contexts helps the new masonry work or restorations respect the region’s architectural heritage.

Resources:

McCullough demonstrates a variety of masonry jointers that are typically more common in specific regions based on climate conditions. You can find some of the more common jointers, including the flat jointer, concave, and convex jointers, at most home centers and masonry supply houses across the country. Specialty jointers, like the grapevine jointer, the rat’s tail jointer, and the skate jointer, are more specialized tools you’ll find at masonry supply stores. The ones shown in the segment are from Bon.

Expert assistance with this segment was provided by MJM Masonry.