What type of cement must be used for vent connectors entering a chimney?

The correct choice is based on the requirement for appropriate materials to ensure safety and compliance with building codes. When vent connectors enter a chimney, they must utilize an approved type of cement that can withstand the high temperatures and corrosive elements associated with exhaust gases from gas appliances.

Approved cement is specifically designed to meet safety standards and performance specifications set forth by regulatory bodies. This type of cement provides the necessary durability and strength, ensuring that the structure remains secure and functional over time.

In contrast, standard cement may not possess the specific properties required for high-temperature applications or resistance to the substances found in flue gases, making it less suitable for this application. Polymer and non-toxic cements, while they may have advantages in other contexts, do not meet the specific standards required for vent connectors entering chimneys, thus compromising safety and compliance.