Which type of concrete masonry unit (CMU) has more space for placing conduit or other utilities?

• A. Two core block
• B. Four core block
• C. Solid block
• D. Split face block

Answer: (B)

Hollow cores inside CMU units are where you place conduits and other utilities. The more cores a block has, the more interior space you have to run electrical, data, or plumbing without adding separate chase walls. A four-core block provides more hollow area than a two-core block and far more than a solid block, which has no empty interior space. The split-face designation refers to surface texture and doesn’t inherently change how much space is available inside the block—the key factor is the core count. So for placing conduits and utilities, the four-core CMU offers the most room.