What Are The Protective Components of A Chimney?

There is more to a masonry chimney than a column of bricks. There are protective components of chimneys that need upkeep. The best way to avoid common fireplace hazards or having to deal with an unstable or malfunctioning chimney is by scheduling annual chimney inspections for key protective chimney features.

Chimney Flue Liner

The chimney flue allows combustion gases travel through before being expelled to the out-of-doors. Chimney flue liners have been required since the 1940s when it was determined that they are crucial chimney safety features. Flue liners defend the home and family against potentially life-threatening dangers. If a chimney flue liner is damaged, such as a tiny crack, two things can happen:

• First, the toxic fumes from combustion gases can enter the home. Those fumes include deadly carbon monoxide (CO). Known as The Silent Killer, carbon monoxide is unseen, has no odor or taste, and is symptomless until it is usually too late to make a safe escape from the fumes.
• Secondly, combustible materials near the chimney can undergo a change known as pyrolysis, which lowers the temperature at which the materials combust. Pyrolysis causes tragic house fires every year.
  Of the protective components of chimneys, none is more important than the chimney flue liner. However, it cannot be thoroughly checked for damage without special equipment used by professional chimney sweeps. It’s often during Level 2 chimney inspections that flue liner damage is discovered.

Chimney Cap

Chimney caps are installed over chimney flue openings, and they are protective chimney components in several ways. The basic function of a chimney cap is to keep moisture from going directly into the chimney. If there is no chimney cap to keep out rain, sleet, and snow, a chimney system becomes vulnerable to moisture, its worst enemy. Preventing moisture intrusion is not easy, partly because bricks are porous. When water gets inside bricks, it ultimately destroys them during freezing and thawing cycles in winter, when the water expands and contracts. When a chimney cap includes mesh, another function it provides is to work as a spark guard. Without the chimney cap mesh, when embers float up the chimney flue, they are far more likely to escape and potentially start a roof fire. The mesh also prevents debris and animals from getting into the flue and causing a blockage. When twigs, leaves, nests, and other debris are inside the flue, the potential for a chimney fire is increased. Also, the chimney draft can be obstructed, resulting in toxic fumes entering the home.

Chimney Crown

The chimney crown is the white part of the chimney at the top. It is a protective component of chimneys that prevents water from infiltrating the masonry system via the space between the chimney exterior and the flue lining. The crown also deflects rain, snow, and hail from the chimney stack. It’s common for chimney crowns to crack and deteriorate due to exposure to outdoor elements. To prevent chimney crown damage, choose an outside-mount custom chimney cap that covers the crown as well as the flue top. Damage to chimney crowns is usually discovered by a chimney sweep who is on the roof conducting a chimney inspection. Visit our Chimney Specialists Inc. showroom at 869 Main Street, Highland, WI 53543. Call (608) 929-4887 or contact us online.