Chimney Caps Don't Just Keep The Squirrels Out!
A fireplace damper can get rusty and fail without a chimney cap due to the increased exposure to moisture and debris. Here's how this happens:
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Exposure to Rain and Snow
Without a chimney cap, rain and snow can enter the chimney directly. The water can accumulate on the damper, leading to rust over time as the metal components oxidize.
Moisture Accumulation
Moisture from rain, snow, or even humidity can accumulate inside the chimney. This creates a damp environment, which is conducive to rust formation on the damper and other metal parts.
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Debris and Animals
Without a cap, leaves, twigs, and other debris can fall into the chimney. These materials can retain moisture, creating a damp environment that promotes rust. Additionally, animals might enter the chimney, leaving behind droppings or nesting materials that can also retain moisture.
Freezing and Thawing Cycles
In colder climates, the presence of water can lead to freezing and thawing cycles. This can cause expansion and contraction of metal components, leading to cracks or damage that expose more of the metal to moisture, accelerating the rusting process.
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Creosote and Soot Buildup
Without a cap, the chimney may have an increased buildup of creosote and soot, which can combine with moisture to create an acidic environment. This acidic residue can corrode metal components, including the damper.
Effects of Wind
Wind can drive rain and snow into the chimney, increasing the amount of moisture that enters. Wind can also carry salt in coastal areas, which can be particularly corrosive to metal components.
Summary
A chimney cap acts as a barrier against moisture, debris, and animals, protecting the damper and other internal components. Without a cap, these elements can enter the chimney freely, leading to increased moisture and creating conditions that promote rust formation on the damper. Installing a chimney cap is a simple and effective way to prevent rust and prolong the life of your chimney components.

