CCS Chimney Repair & Installation 2 — Questions and Answers
Question 1: What is the minimum thickness required for a refractory mortar joint in a firebox?
- 1/16 inch
- 1/4 inch (Correct answer)
- 1/2 inch
- 3/4 inch
Correct answer: 1/4 inch
Refractory mortar joints in a firebox should be no more than 1/4 inch thick to maintain structural integrity and heat resistance.
Question 2: Which condition requires immediate removal from service of a factory-built fireplace?
- Minor surface rust on the damper
- Warped or cracked firebox panels (Correct answer)
- Slightly discolored glass doors
- A small gap in the decorative trim
Correct answer: Warped or cracked firebox panels
Warped or cracked firebox panels in a factory-built fireplace compromise the unit's structural integrity and create a fire and carbon monoxide hazard.
Question 3: When installing a new chimney liner in an existing masonry chimney, what must be done before liner insertion?
- Apply waterproofing to the exterior
- Inspect and clean the flue of all debris (Correct answer)
- Install a new damper assembly
- Remove the existing chimney cap
Correct answer: Inspect and clean the flue of all debris
The flue must be thoroughly inspected and cleaned of all debris, creosote, and obstructions before a new liner is inserted.
Question 4: What type of mortar is appropriate for tuckpointing chimney joints exposed to flue gases?
- Portland cement mortar (Type S)
- Gypsum-based mortar
- Refractory mortar rated for high temperatures (Correct answer)
- Standard masonry mortar (Type N)
Correct answer: Refractory mortar rated for high temperatures
Refractory mortar rated for high temperatures must be used for joints inside the flue that are exposed to combustion gases and extreme heat.
Question 5: A homeowner reports smoke entering the room when using their fireplace after a recent chimney cap installation. What is the most likely cause?
- The flue liner has cracked
- The new cap is too restrictive for the flue size (Correct answer)
- The damper needs replacement
- Creosote buildup is blocking the flue
Correct answer: The new cap is too restrictive for the flue size
An improperly sized chimney cap can restrict draft and cause smoke to back up into the living space.
Question 6: What is the purpose of a smoke chamber's corbeling during chimney construction?
- To support the chimney cap
- To gradually transition the flue from the firebox opening to the flue liner (Correct answer)
- To provide a ledge for the damper
- To reinforce the exterior chimney walls
Correct answer: To gradually transition the flue from the firebox opening to the flue liner
The corbeled smoke chamber transitions the wide firebox opening to the narrower flue, improving draft and directing smoke upward.
Question 7: Which NFPA standard governs the inspection, cleaning, and restoration of chimneys, fireplaces, and venting systems?
- NFPA 70
- NFPA 101
- NFPA 211 (Correct answer)
- NFPA 31
Correct answer: NFPA 211
NFPA 211 is the Standard for Chimneys, Fireplaces, Vents, and Solid Fuel-Burning Appliances, which chimney professionals must follow.
CCS Chimney Repair & Installation 2
What is the minimum thickness required for a refractory mortar joint in a firebox?