CCS Fire Prevention & Creosote Management 3 — Questions and Answers
Question 1: Which condition creates the highest risk of a chimney fire within a wood stove system?
- Burning two cords of dry oak per season
- Using an oversized stove connected to a small-diameter flue
- Allowing the stovepipe to become red hot during a hot burn (Correct answer)
- Operating the stove with the air control fully open at all times
Correct answer: Allowing the stovepipe to become red hot during a hot burn
A red-hot stovepipe indicates the connected flue is likely already experiencing dangerously elevated temperatures consistent with a chimney fire.
Question 2: What role does the 'stack effect' play in chimney fire risk?
- It cools the flue gases rapidly, reducing creosote condensation
- A strong stack effect increases draft and reduces the likelihood of slow, smoldering fires (Correct answer)
- It forces combustion gases into the living space, increasing CO risk
- It draws outside air backward through the flue, increasing oxygen for creosote ignition
Correct answer: A strong stack effect increases draft and reduces the likelihood of slow, smoldering fires
A strong stack effect maintains sufficient draft to draw combustion gases quickly through the flue, reducing the cool-surface condensation that forms creosote.
Question 3: After applying a creosote removal chemical to a Class 3 deposit, how long should a sweep typically wait before attempting mechanical removal?
- No waiting period is required; remove immediately
- A minimum of 24 hours as directed by most product manufacturers (Correct answer)
- At least 2 weeks to allow full penetration
- Until the next heating season
Correct answer: A minimum of 24 hours as directed by most product manufacturers
Most chemical creosote modifiers require approximately 24 hours (or as specified by the manufacturer) to alter the deposit's structure before brushing.
Question 4: Which type of wood produces the least creosote when burned properly in a well-maintained fireplace?
- Green pine with high resin content
- Wet oak less than six months old
- Kiln-dried or seasoned hardwood with less than 20% moisture content (Correct answer)
- Pressure-treated lumber cut into fireplace lengths
Correct answer: Kiln-dried or seasoned hardwood with less than 20% moisture content
Properly seasoned hardwood with low moisture content burns hotter and more completely, producing the least amount of creosote.
Question 5: In a two-story home, the second-floor bedroom shares a wall with the chimney. After a chimney fire, what is the most critical inspection concern for that bedroom?
- Whether the bedroom window seals properly against smoke odor
- Whether heat from the chimney fire has ignited adjacent combustible framing or materials (Correct answer)
- Whether the fireplace damper remains open to ventilate the room
- Whether the chimney height above the roof is adequate
Correct answer: Whether heat from the chimney fire has ignited adjacent combustible framing or materials
Chimney fires generate extreme heat that can transfer through cracked masonry or improper clearances and ignite combustible materials in adjacent wall cavities.
Question 6: What is the recommended minimum flue gas temperature to minimize creosote condensation in a masonry chimney?
- 100°F (38°C)
- 150°F (66°C)
- 250°F (121°C) (Correct answer)
- 400°F (204°C)
Correct answer: 250°F (121°C)
Maintaining flue gas temperatures above approximately 250°F (121°C) helps prevent the condensation of unburned hydrocarbons that form creosote.
Question 7: A customer burns exclusively artificial wax logs. What creosote-related advice should the sweep provide?
- Artificial wax logs produce no creosote and require no annual sweeping
- Wax logs produce a different type of deposit that requires specialized chemical removers only
- Annual inspection is still required; wax logs can leave their own residue and mask underlying deposits (Correct answer)
- Wax logs are banned by EPA regulations in most US states
Correct answer: Annual inspection is still required; wax logs can leave their own residue and mask underlying deposits
While wax logs generally produce less creosote than wood, they can leave waxy residue and an annual inspection is still required by NFPA 211.
CCS Fire Prevention & Creosote Management 3
Which condition creates the highest risk of a chimney fire within a wood stove system?