Many homes, particularly in rural areas, rely heavily on wood burning fireplaces for home heating. Fireplaces can also serve as an aesthetically pleasing and comforting addition to a home. Chimneys and their respective safety features for wood burning fireplaces are essential. Safety features such as rain caps and spark arrestors are important additions to help maintain a clean chimney flue, while also preventing sparks from leaving the chimney and creating fire hazards.
A spark arrestor is a metal mesh screen that surrounds the top of the chimney. The spark arrestor has two main functions. The main purpose of the spark arrestor is to prevent sparks created in the fireplace from leaving the chimney. This inhibits sparks from encountering combustible materials, such as dry grass, wood debris, and the homes building materials.
Additionally, a spark arrestor prevents pests and debris from entering the chimney flue. Pests, such as birds, squirrels, and even raccoons have been known to enter an unguarded chimney flue and build nests or otherwise block the flue. Leaves, branches, and other organic materials can also become lodged in an unprotected flue. Blockage in the flue can cause improper ventilation of smoke and ash which may allow it to enter the home. Smoke from a wood burning fireplace creates carbon monoxide, which is a dangerous gas that can pose serious health risks for a home’s occupants.
Next, the rain cap assists with the prevention of spark, pest, debris, rainwater, or snow from entering the chimney and fireplace. Water that enters a chimney can cause moss, mold, and mildew growth which can also damage chimney liners, mortar joints, and dampers over time.
Rain caps and spark arrestors serve complimentary functions and are often sold and installed as a single attachment. A spark arrestor is attached to the top of a chimney flue often using a spreader bar. The rain cap is then secured to the top of the spark arrestor using butterfly screws or wing nuts.
Many older homes have chimneys that are missing these essential safety components. Often the presence of a rain cap and spark arrestor can be visible from the ground level, however this is not always the case. Because accessing a chimney can be a dangerous endeavor for a homeowner, it is recommended that a qualified inspector examines chimneys to determine the presence and condition of spark arrestors and rain caps.
Check out the video below to learn more about a simple rain cap and spark arrestor installation: