Chimney Problems · Brick & Masonry
Why Are My Chimney Bricks Flaking or Breaking Apart?
When the surface of chimney bricks begins to flake, chip or break away, the condition is often called spalling. Moisture exposure, freezing and thawing, aging materials and other masonry conditions can contribute to this type of deterioration.
The basics
What Is Chimney Brick Spalling?
Spalling is when the face or outer surface of a brick begins to chip, flake or break away. It can range from small surface flakes to more visible deterioration across several bricks.
Spalling is different from ordinary dirt, soot or staining, which sits on the surface without damaging the brick. The mortar around spalling brick may also show signs of wear. Not all surface wear is severe, but it is worth keeping an eye on.
Causes
What Causes Chimney Bricks to Spall?
Spalling usually develops gradually, and several factors can contribute.
Repeated moisture exposure
Rain and snow regularly wet the exterior of a chimney, which stands exposed above the roofline.
Water absorption
Brick and mortar are porous and can take in water, especially as they age.
Freezing and thawing
Absorbed water expands when it freezes, which can gradually push the brick face apart.
Weather exposure
Sun, wind and seasonal temperature swings add to long-term wear on exterior masonry.
Deteriorated mortar joints
Worn or open joints can let more water reach the surrounding brick.
Crown problems
A cracked or worn crown can allow more water near the top of the chimney.
Age and material deterioration
Masonry materials naturally weaken over many years of service.
Warning signs
What Does Spalling Chimney Brick Look Like?
These signs can often be noticed from the ground or a safe vantage point. There is no need to go onto the roof.
- Flaking brick surfaces
- Chipped brick faces
- Pieces of brick near the base of the chimney
- Rough or recessed brick surfaces
- Cracks in the brick
- Loose material on or around the chimney
- Visible deterioration near mortar joints
Moisture
Can Moisture Cause Chimney Brick Damage?
Moisture that enters or remains in masonry can contribute to deterioration, particularly when temperatures repeatedly freeze and thaw. Water may reach the brick from several sources, including rain on the exterior, the crown, the cap area and worn mortar joints. Read more about chimney leaks and water damage.
Top of the chimney
Can Chimney Crown Damage Affect the Bricks Below?
The crown helps shed water away from the top of the chimney. When it deteriorates, the masonry near the top may see more weather exposure. The crown is one possible factor, not always the cause. Learn what a cracked chimney crown can mean.
Repair
Spalling Brick and Chimney Masonry Repair
The appropriate repair depends on the condition found, including:
- How much brick is affected
- The condition of the mortar
- The condition of the crown
- Where the deterioration is located
- Any other visible chimney damage
We evaluate the chimney first and explain what we recommend before any work goes ahead. Learn more about our chimney masonry repair.
Inspection
Why a Chimney Inspection Can Help
An inspection can help identify visible:
- Brick deterioration
- Mortar damage
- Crown concerns
- Moisture staining
- Other accessible chimney conditions
Learn more about our chimney inspection service.
Beyond masonry
When General Chimney Repair May Be Needed
Chimney problems sometimes involve more than brick and mortar. Masonry repair focuses on visible brick, mortar and crown concerns, while general chimney repair may cover other chimney or fireplace components depending on what is found. See our chimney repair services.
Local service
Spalling Chimney Bricks in Manalapan Township and Monmouth County
Chimneys in Manalapan Township, Freehold, Marlboro Township, Colts Neck and across Monmouth County stand exposed to rain, snow and seasonal freezing and thawing, which can contribute to gradual wear on exterior brick and mortar.
See all of our chimney service areas, or return to the Mr. Chimney Sweep Inc. homepage.
Next steps
What Should You Do If Your Chimney Bricks Are Flaking?
- Note where the deterioration is visible.
- Look for brick pieces or mortar debris from a safe location.
- Watch for staining or other moisture signs.
- Do not climb onto the roof to inspect the chimney.
- Schedule an inspection if deterioration is visible or progressing.
- Discuss masonry repair after the condition is evaluated.
Common questions
Spalling Chimney Brick FAQs
What does spalling brick mean?+
Spalling is when the face or outer surface of a brick begins to chip, flake or break away. It can range from small surface flakes to more noticeable deterioration.
Why are my chimney bricks flaking?+
Common contributors include repeated moisture exposure, water absorption, freeze-thaw cycles, deteriorated mortar, crown problems and the age of the materials.
Can water cause chimney bricks to crumble?+
Moisture that enters or stays in masonry can contribute to deterioration over time, particularly when it repeatedly freezes and thaws.
Does freezing weather damage chimney masonry?+
Repeated freezing and thawing of absorbed water can gradually loosen mortar and wear down brick faces.
Is spalling the same as cracked mortar?+
No. Spalling affects the brick itself, while cracked mortar affects the joints between bricks. The two often appear together because they share the same weather exposure.
Should damaged chimney bricks be inspected?+
If deterioration is visible or seems to be progressing, an inspection can help identify the condition of the brick, mortar, crown and other visible areas.
Do you inspect chimney brick damage in Manalapan Township, NJ?+
Yes. Mr. Chimney Sweep Inc. is based in Manalapan Township and provides chimney inspection there and in nearby Monmouth County communities.
Concerned About Damaged Chimney Bricks?
If you notice flaking, cracking, crumbling or other visible deterioration in your chimney brickwork, contact Mr. Chimney Sweep Inc. to discuss inspection and service availability.
220 Taylors Mills Rd, Manalapan Township, NJ 07726 · Monday–Saturday: 9:00 AM–5:00 PM