Curved chimneys & sulphation:

This article describes the cause, inspection, and evaluation of leaning-curved chimneys. Often a brick chimney is visibly curved or leaning above the building roof line.

If the cause is sulphation the chimney curving process is well understood, but further inspection of the chimney flue and the chimney stability are in order since a badly damaged brick chimney may have an unsafe flue or may collapse.

Our page top photo shows a curved brick chimney above the rooftop of a home in Hudson, NY. Look closely at the left edge of the brick chimney to best see this deformation.

Curved Brick Chimneys: Definition of Chimney Sulphation

Photos: curved chimneys where the curving is probably due to sulphatin as we will describe and explain here.

These articles on chimneys and chimney safety provide detailed suggestions describing how to perform a thorough visual inspection of chimneys for safety and other defects.

Chimney inspection methods and chimney repair methods are also discussed.

[Click to enlarge any image]

Curves or bending in brick masonry chimneys are common on older homes and may not be evidence of actual chimney settlement or movement.

Below: a curved brick chimney atop a home in Kingston, New York.

Following our leaning chimnney sketch, courtesy of Carson Dunlop Associates, Toronto, we show a quite-curved brick chimney atop an older home in Kingston, NY. The second chimney at right in the photo, has its narrow side facing the direction of principal weather and did not show the same sulphation curving.

A brick chimney may curve away from its most weather-exposed side due to sulphation: a term which describes expanding brick mortar joints caused by the combination of water and sulphur or other minerals.

As Carson Dunlop's sketch points out, curved chimneys seen above the roof line often are found in northern climates where:

• The masonry chimney has an un-lined flue
• The heating fuel was oil or coal containing high levels of sulphur
• The chimney is tall

A curved brick flue may might need repair or replacement but it's not certain. The flue interior needs to be inspected thoroughly for damage and stability.

Below: curved brick chimneys in Duluth Minnesota in 2017. The chimney side that faces west, the direction of more-severe winter storms in the Duluth area shows the characteristic convex curve towards the weather.

Our curved chimney photo below, also on a Duluth home, is quite tall, very curved, and has bracing added. [Click to enlarge any image]

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Continue reading at CHIMNEY MOVEMENT, ONGOING vs STATIC or select a topic from the closely-related articles below, or see the complete ARTICLE INDEX.

Or see these

Recommended Articles

• BRACING for MASONRY CHIMNEYS
• BRICK CHIMNEY CRACKS & COLLAPSE
• CHIMNEY INSPECTION DIAGNOSIS REPAIR - home
• CHIMNEY COLLAPSE RISKS, REPAIRS
• CHIMNEY CRACK DETECTION & DIAGNOSIS
• CHIMNEY DAMAGE by LEAKS & FROST
• CHIMNEY LEANING, SEPARATION, MOVEMENT
• CHIMNEY INSPECTION from GROUND
• CRACKED CHIMNEYS, MASONRY BLOCK
• CURVED BRICK CHIMNEYS, SULPHATION

Suggested citation for this web page

CURVED BRICK CHIMNEYS, SULPHATION at InspectApedia.com - online encyclopedia of building & environmental inspection, testing, diagnosis, repair, & problem prevention advice.

Or see this

INDEX to RELATED ARTICLES: ARTICLE INDEX to CHIMNEYS & FLUES

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Citations & References

In addition to any citations in the article above, a full list is available on request.

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