Masonry Chimneys Flashcards
What should be inspected during a visual examination of the outer chimney structure?
Roof, flashing, moisture, and structure.
What is the minimum height requirement for chimneys above the roof?
3 feet high, 2 feet taller than anything within 10 feet.
3 feet up: The vent must be at least 3 feet higher than the part of the roof it’s going through. This ensures it’s high enough to work properly.
2 feet higher: The vent must be 2 feet taller than any roof or structure within 10 feet horizontally. This keeps the airflow clear and avoids obstructions.
Think of it like “3 feet up, 2 feet out” — the vent needs to be tall enough to clear the roof and above nearby roofs for good airflow.
What materials are typically used for masonry chimneys?
Brick, stone, or concrete blocks, which may be part of a manufactured chimney system.
What causes masonry and mortar deterioration? or
(What causes brick and mortar to fail?
Weather, moisture intrusion, and freezing cause deterioration, leading to spalling and erosion of the masonry and mortar.
What is spalling, and how can it be addressed? or
(What’s spalling, and how do you fix it?)
Spalling occurs when brick or mortar erodes due to moisture. The solution is re-pointing, where affected mortar is replaced with fresh mortar.
(Bricks/mortar crumble. Fix it with re-pointing (replace mortar).
What are the two purposes of a chimney crown?
Seal the area between the chimney flue and masonry structure to prevent water intrusion.
Extend beyond the chimney to allow water to drip off and not wick into the masonry.
(Keeps water out and redirects water away from the chimney)
What is the difference between a chimney cap and a rain cap?
(What does a rain cap do?)
Chimney cap seals the top of the chimney structure.
Rain cap protects the inside of the chimney flue from weather and wildlife intrusion.
(Blocks rain, wildlife, and downdrafts.)
What are rain caps made of, and why are they important?
Made of metal (stainless steel, copper, or galvanized steel), rain caps prevent weather, wildlife, downdrafts, and can act as dampers.
What should inspectors check regarding chimney flues?
(What do you look for in chimney flues?)
Inspect for damage, collapse, signs of previous fires, and any debris. Flues venting fossil-fuel appliances must have continuous metal liners.
(Damage, debris, or signs of fires.)
What six chimney components should a home inspector evaluate?
- Material of the chimney
- Condition of the chimney stack
- Condition of the flashings
- Condition of the chimney cap
- Condition of the rain cap (if present)
- Chimney height and safety compliance
A typical chimney is a minimum of ____ feet high.
3 feet
If a roof ridge is closer than 10 feet to a chimney, the stack should be ____ feet higher.
2 feet
Chipping or breaking off of masonry or mortar is called
spalling
Question: The process of repairing missing mortar between brick joints is called _________.
Re-pointing
The difference between a chimney cap and a rain cap is ___________.
A chimney cap protects the structure, and a rain cap protects the inside of the flue.
