What Is the Purpose of a Chimney Cap?

Chimney caps usually are made of aluminum, copper, or galvanized or stainless steel. Metal chimneys commonly have caps when purchased, while masonry chimneys may need one added if the owner decides this is beneficial. Chimney caps serve a number of purposes, including improving home safety, preventing disruptive occurrences and avoiding costly repairs.

Birds

It is common for birds to enter a chimney that does not have a chimney cap, typically looking for a nesting area. The birds can also fly into the fireplace and, if the fireplace door is open, right into the house.

Animals

Animals also are known to get into chimneys, particularly squirrels, raccoons and bats.

Nesting Material

If nesting material in the chimney is not removed, the blockage can cause carbon monoxide to build up in the house when the fireplace or wood stove is used.

Rain

Rain coming into the chimney can cause unpleasant odors and damage flue walls. Rain also may run down into the stovepipe and the stove itself, or into the fireplace, and cause further damage.

Wind

Another purpose of a chimney cap is to minimize wind downdrafts that cause smoke.

Embers

A chimney cap prevents embers and sparks from flying out of the chimney and possibly damaging the roof.