Masonry Joints: Types and Applications
Words: Paul Bender
Words and Photos: Paul Bender, Product Marketing & Communications Manager, Bon Tool
Masonry joints are multi-functional bonding agents that both adhere masonry elements together and provide weather protection to the finished masonry work. Utilizing joints in masonry is historical in nature given that it’s the oldest mode of finishing brickwork. Before varying joint tooling existed a trowel was used not only to lay the brick but also to create the masonry joints that bond the brick and stone units together. Commercially available striking tools didn’t become fully available until the mid-1800s.
At Bon Tool Company and other manufacturers with a wheelhouse in Masonry, some vital hand tools would include; sled runners, slickers, rakers, and jointers. All of the above have similar utilization, the focus of this article will further examine the varying types of Masonry Joints and the need for varying hand tools to achieve the varying and proper aesthetics.
Several types of joint profiles exist. Leading with the most popular: Concave, which has that reputation since it provides great resistance to the penetration of water. This joint profile is the most popular and durable of all the joints, followed by ‘V’ and Weathered type joints.
Other types of joints include Weathered, Struck, Raked, Convex, ‘V’, Flush, Beaded, Extruded, and Grapevine. To further understand the profiles of the above-mentioned joints please see the ‘Common Mortar Joints’ Poster. For additional reference below is a brief overview of each type of common mortar joint:
- Raked: The only joint where mortar is removed rather than compressed by utilizing a set nail adjusted to depth.
- Grapevine: Contains a raised bit either square or round to produce a recessed groove, AKA colonial joint.
- Extruded: Untouched/un-tooled, “squeezed” joint in appearance.
- Concave: Evenly curved and sealed appearance in mortar joint; almost always used with CMU’s and most popular with brickwork
- V (Vee): Sunken in appearance but with pronounced “vee” shape
- Struck: These joints replicate American colonial brickwork it tapers from the bottom front edge of one course inward behind the top front edge of the course below it
- Flush: Typically trowel or flat iron finished to the brick surface, the joint is not compressed
- Weathered: Tapers inward from the top front edge of one course and behind the bottom edge of course above it
- Beaded: These joints produce a raised bead along the joint’s center, it can be square-like in nature or half round often used in stonework replicating pre 20th century masonry
Note that when working with solid masonry units, the mortar must completely fill all joints, both bed (horizontal), and head (vertical). Above all, always remember, “You can lay them crooked, but always make sure you strike them straight.”