Chimneys are often one of the most neglected appliances in a home. The simple appearance and misunderstanding hide their complex construction and performance needs. However, a chimney deteriorated by constant exposure to the weather can be a potential safety hazard. Weather-damaged lining systems, flue obstructions and loose masonry all pose a threat to homeowners. Routine chimney inspections and maintenance is essential to prevent damage, deterioration and future high-cost repairs.

A masonry chimney is constructed of a variety of masonry and metal materials and most include a combination of brick, mortar, concrete, concrete block, stone, glue tile, steel and cast iron. Most of these materials are adversely affected by direct contact with water or water penetration.

All masonry chimneys will experience accelerated deterioration from prolonged contact with water. The masonry materials deteriorate quickly when exposed to the freeze/thaw process where moisture that has penetrated the materials periodically freeze and expand, causing undue stress. The water exposure in the chimney will also rust steel and cast iron which will weaken or destroy the metal components of the fireplace.

Water penetration can cause damage to the interior and exterior of any masonry chimney, including:

  • Rusted damper assemblies
  • Deteriorated metal or masonry firebox assemblies
  • Rusted fireplace accessories and glass doors
  • Water stained walls and ceiling
  • Clogged clean out area
  • Rotting adjacent wood and ruined wall coverings
  • Deteriorated central heating system
  • Decayed exterior mortar
  • Stained chimney exterior
  • Collapsed hearth support
  • Cracked or deteriorated flue lining system
  • Tilted or collapsed chimney structure
  • Chimney settlement

Also, a highly unpleasant odor can be caused by water mixing with creosote buildup in a wood-burning chimney. This smell can then diffuse throughout the home.

Visit us next week for Part 2 of this article that will explain how to best prevent water damage to your wood-burning fireplace.