Reference tables

Look-up charts built from stable flue geometry and labeled industry planning conventions — flue size by fireplace opening (the signature data asset), liner size by appliance and standard clay-tile sizes, creosote stages 1–3, NFPA 211 inspection Levels 1–3, clearance-to-combustibles, and chimney repair / service cost bands by job.

Typical published planning values — NOT a certified spec or professional advice. The 1/10–1/12 flue rule, the 3-2-10 height rule, creosote stages, NFPA 211 inspection levels, clearances and cost bands vary by chimney and appliance; confirm your exact dimensions and follow the manufacturer’s instructions and local code. Creosote, chimney fire, carbon monoxide, structural and code judgement are a CSIA-certified sweep / licensed mason / NFPA 211 / local-code matter — have a certified professional inspect; never a step-by-step procedure or medical advice here.