Where should the measurement be taken from when determining the vertical chimney height to the roof?

When determining the vertical chimney height to the roof, the measurement should be taken from the bottom of the chimney. This is important because the height of the chimney is crucial for ensuring proper draft and venting of exhaust gases. The bottom of the chimney serves as the point of reference for assessing whether the chimney meets the minimum height requirements over the roof line, which helps prevent downdrafts and assures effective operation of the heating system.

Taking measurements from the bottom ensures an accurate assessment of how high the chimney extends above the roof, which is necessary for compliance with local codes and regulations. Additionally, this approach provides a standardized method for measuring chimney height, which can vary based on chimney designs and installation requirements.