What is the maximum size of wire mesh openings for a spark arrestor on a chimney cap?

The maximum size of wire mesh openings for a spark arrestor on a chimney cap is 1/2 inch. This size is critical because it prevents sparks and embers from escaping the chimney while still allowing for adequate airflow. If the openings are too large, there is an increased risk of fire as sparks may escape and ignite nearby combustibles. The 1/2 inch mesh is a standard that balances effective protection with functionality, preventing blockages while ensuring that no hazardous materials can exit the chimney. This specification is important for promoting safety in residential areas and adhering to building codes and regulations regarding chimney construction and maintenance.