Chimney Masters Blog

Humidity affects masonry chimneys by loading brick, mortar and clay flue tile with water vapor they readily absorb. That moisture drives freeze-thaw spalling when temperatures swing, corrodes dampers and metal components, dissolves mortar salts into white efflorescence, condenses inside cool flues, and reactivates creosote and animal-debris odors. North Carolina's humid climate makes crown cracks, failed flashing and missing caps far more damaging than the same defects would