When should a raked joint be used in masonry work?

A raked joint is used in masonry work when the plans specify a distinct and uniform joint depth. This type of joint is characterized by its concave profile, which allows for a neat and aesthetically pleasing finish that enhances the overall appearance of the masonry. When the project specifications call for a specific depth, a raked joint ensures that the masonry adheres to these requirements, contributing to both structural integrity and the desired visual effect.

The other options present scenarios that do not align with the primary purpose of a raked joint. While insulation concerns might necessitate different techniques or materials in masonry, they do not directly relate to the use or requirement of a raked joint. Additionally, using a raked joint is typically an aesthetic choice, so it is not appropriate to consider it when appearance is not a concern. Lastly, a raked joint is applicable to various types of masonry work, not just brick alone, making the focus on brick an incorrect context for its use.