Brick Mortar Joints in Construction

In the realm of construction, the tiny spaces between bricks or blocks play a crucial role. These spaces, known as mortar joints, are filled with mortar or grout mixtures. The choice of mortar joint type in masonry construction not only affects aesthetics but also influences water resistance and structural integrity. In this comprehensive blog post, we will dissect the different types of brick mortar joints and their significance in construction. Additionally, we will explore the materials used in mortar joints and their environmental impact.

Types of Brick Mortar Joints

Let’s explore the most common types of mortar joints used in brick masonry construction:

1. Struck Mortar Joint

The struck mortar joint is typically used for horizontal joints but is not recommended for exterior walls due to water seepage concerns. In this joint, the bottom edge is recessed, while the top edge is finished flat with the brick. The slope of this joint directs water away and is ideal for interior walls.

2. Concave Mortar Joint

The concave joint is created using a curved steel jointing tool. It is popular for its resistance to rainwater penetration and its ability to provide a tight seal. Properly placed concave mortar joints effectively resist water penetration.

3. Weathered Mortar Joint

Weathered joints are commonly used for horizontal joints. They allow water to shed away from the joint, preventing moisture-related issues. However, improper adherence of mortar can lead to water movement beneath the joint, potentially causing shrinkage cracks.

4. Raked Mortar Joint

Similar to struck joints, raked joints are not recommended for exterior walls. They create a ledge that can trap snow, ice, or water on top of the bricks. This type of joint is best suited for interior walls.

5. V-Joint

V-joints do not provide water penetration protection due to their geometry. Proper tooling of V-joints is essential to prevent water accumulation and penetration into the brick.

6. Flush Mortar Joint

Flush joints are used when the surface requires plastering and finishing. These joints are hidden after construction. Creating watertight flush joints can be time-consuming, but they are essential for water resistance.

7. Extruded Joint

Extruded joints do not require tooling. Excess mortar naturally squeezes out, forming an extrusion between the bricks. However, these joints may degrade over time when exposed to various weather conditions.

Materials Used in Mortar Joints

The composition of mortar joints is a critical factor in construction. Mortar typically consists of three main components:

a. Portland Cement

Portland cement is a primary binding agent in mortar. It provides strength and durability to the joint. However, the production of Portland cement is associated with significant carbon emissions.

b. Sand

Sand is used to add bulk to the mortar mix. Different types of sand can be used, and their quality can affect the strength and texture of the mortar.

c. Water

Water is essential for activating the chemical reactions that make the mortar harden. The right water-to-cement ratio is crucial for the mortar’s performance.

Environmental Considerations

As environmental awareness grows, the construction industry is seeking more sustainable practices. Mortar joints can also contribute to these efforts:

8. Lime Mortar

Lime mortar is an environmentally friendly alternative to Portland cement mortar. It has a lower carbon footprint and is often used in historic preservation projects.

9. Recycled Materials

Using recycled materials, such as crushed glass or recycled aggregates, in mortar mixes can reduce the environmental impact of construction.


In the world of construction, the choice of mortar joint type is not merely a matter of aesthetics but also a critical factor for maintaining the structural integrity and water resistance of masonry walls. Understanding the various types of brick mortar joints and their applications is essential for any construction professional.

Furthermore, considering the environmental impact of mortar materials is becoming increasingly important in today’s sustainable construction practices. By selecting the right mortar joint pattern and materials, you can ensure that your construction project not only looks appealing but also contributes to a greener and more sustainable future for the construction industry. Whether it’s the functional concave joint or the eco-friendly lime mortar, each choice has a unique role in the intricate art of masonry construction.

Scroll to Top