Comprehensive Chimney Height Calculator

Proper chimney height is critical for safety and performance. It ensures adequate draft to expel combustible gases and prevents downdrafts caused by wind turbulence from the roof or nearby objects. This calculator helps estimate the required height based on the widely adopted “3-2-10 Rule”.

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Any part of the building within this distance is an obstruction.
This helps calculate the total chimney height.

Understanding the “3-2-10 Rule”

This calculator is based on three fundamental safety rules that are common in building codes:

  • The 3-Foot Rule: The chimney must extend at least 3 feet above the highest point where it passes through the roof. This provides a baseline clearance.
  • The 2-Foot Rule: The chimney must be at least 2 feet taller than any part of the building that is within a 10-foot horizontal radius.
  • The 10-Foot Rule: This defines the horizontal radius (10 feet) for the 2-Foot Rule. Common obstructions include the roof ridge, dormers, adjacent walls, or even nearby trees.

The final required height is the maximum value calculated from all applicable rules to ensure universal compliance.

Disclaimer: This tool is for estimation and educational purposes only. Always consult your local building codes and a certified professional before beginning any construction. Regulations can vary by location.