 Chimneys REASONS FOR FAILURE Chimneys suffer from a two-pronged attack throughout their life. The first attack comes from the outside; wind, rain, freezing weather and ice. Over time these elements wear down the exterior's defenses, cracking the crown on the top of the chimney, damaging brickwork, and causing mortar joints to fail and crack. The second attack is from the inside...moisture from gas or oil burning appliances, corrosive elements in the emissions, excessive heat, and thermal shock or shifting foundations. Cracked liners can be replaced without tearing the chimney right down, the crown is removed and the liners are broken up and removed. Note: Clay liners can be cracked (the first time they are used) and have no warranty, stainless steel liners do not crack and can be dropped down into a damaged chimney quickly and without mess. These liners have a lifetime warranty (20 years). A deteriorated chimney where the brickwork has started to fail will need to be completely removed, from the down until firm brick work is reached (often down in the attic or inside a wall). The chimney is then rebuilt on this solid foundation. Furnace flues and chimneys are often neglected. Bird’s nests or other debris can block a chimney causing poisonous gases to enter the home. This dangerous situation could be life threatening. It is extremely important that chimneys and flues be checked or cleaned annually. Stainless steel liners will deteriorate if not cleaned every year they are used. They also should have a cap to stop water entering the flue pipe. The water mixed with soot turns into a steel eating acid that destroys the joints in the liner. | Welcome to BIS | About BIS | Home Inspections | Get Started | Technical FAQ | Contact us |
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