Brickwork is considered an art by many craftsman, and choosing the appropriate mortar joint for the type of wall you will be building is part of the craft. Even if you only have a small project to complete, the type of mortar joint you choose will determine if the joint is waterproof, as well as the overall look of the wall.
Concave joints are the most common because it is waterproof and bonds the bricks very well. To create a joint, the mortar must be compacted into a concave shape using a convex jointer or rod used for the purpose. Concave joints are almost always used for bricks used in residential construction.
Flush joints are easy to create and are waterproof when used with bricks as well. They are created when the excess mortar that is beyond the surface of the bricks is removed by a trowel but no mortar is compacted into the joint between the bricks. For this reason, this joint is not as strong as a concave finish.
Extruded joints are used to create a rustic appearance and is typically used for bricks in a garden setting. In this joint, the mortar is allowed to extrude past the bricks and is not removed. It is water resistant and an easy finish to make; simply use extra mortar when laying your bricks and press down slightly to cause it to seep out.
A V joint stands out from bricks in a V shape. It is created using a V shaped jointer, which will give you perfectly uniform ridges that will stick out from the face of the bricks. This finish directs the water away from the bricks as well as giving an ornamental finish. This is a difficult joint to do correctly, so be sure to practice before attempting to finish an entire wall of bricks using this method.
A raked joint recesses a large amount of mortar (about a 1/4″) from the surface of the bricks. This finish is not waterproof, but it creates a dramatic look that emphasizes the bricks. Use a raking tool to remove the mortar and then smooth it with a dowel in order to create this look.
A weathered joint is very water resistant. You create it by recessing the mortar from the bottom to the top. You can accomplish this finish by using a trowel; also be careful to not recess it more than 3/8″.
A struck joint is not weather resistant. Instead of a weathered finish, a struck finish requires that the mortar slants top to bottom. Shape this finish using the exact same technique as the weathered finish, just reverse the slant.
How you will finish the mortar in a project is an important consideration, so be sure to have practiced the technique you will be using before beginning the actual project. If you are unsure of bricklaying basics, check out your local home improvement store for masonry classes that will help you with the beginning steps of your project.