Which of the following is NOT a requirement for pipe sleeves as stated in installation guidelines?

The correct answer highlights that pipe sleeves cannot be made from just any type of material. This is significant because the material used for pipe sleeves must meet specific requirements to ensure safety, durability, and compatibility with the pipes being housed. Typically, guidelines dictate the use of materials that can withstand environmental factors such as moisture, temperature fluctuations, and potential chemical exposure. Using an inappropriate material can compromise the integrity of the installation and lead to issues such as corrosion, leaks, or even structural failure.

In contrast, the other options reflect standard installation practices and requirements. Ensuring that sleeves are caulked watertight is crucial for preventing water infiltration, which could lead to moisture-related issues. A minimum inside diameter that is larger than the pipe allows for proper clearance and accommodates any necessary movement or expansion. Additionally, the requirement for installation in all masonry walls aims to promote better structural protection and insulation of the piping systems.