An offset is an adjustment in the chimney that will allow it to angle and bend to where it needs to go.

Can a chimney flue be offset?

The answer is “yes”! It’s done every day and is perfectly safe to do so, provided codes are followed and equipment is properly maintained. NFPA 211 (US regulations) states that chimneys can be offset 15° or 30° while CSA B365 (Canadian regulations) states it can be offset at a 30° to 45° angle.

What is the maximum that a chimney can be offset from vertical?

Chimney or vent connectors shall have no more than two 45° offsets with the vertical. The horizontal length shall not exceed 75% of the total vertical height of the total venting system measured from the appliance outlet.