Chimney Safety Institute of America (CSIA) Certification Practice Test

What is the term for the brick situated between flue liners?

1. Wythes

2. Joints

3. Crowns

4. Blocks

The correct answer is: Wythes

The term for the brick situated between flue liners is referred to as "wythes." In masonry, "wythes" represents the vertical sections of a wall, and in the context of chimney construction, they provide structural support and help to maintain the integrity of the chimney. When flue liners are installed, the bricks or masonry courses that are placed between these liners can be termed as wythes, as they fill the space and contribute to the overall stability and functionality of the chimney system. The other options relate to different aspects of masonry or chimney structure. "Joints" typically refer to the spaces between bricks or blocks, which are filled with mortar and help bind the elements together. "Crowns" usually pertain to the protective top section of a chimney that helps prevent water infiltration. Lastly, "blocks" may refer more generally to units of masonry, but do not specifically describe the bricks between flue liners. Understanding these distinctions helps clarify the specific role of wythes in chimney construction.