If you have a wood stove or prefabricated fireplace, your chimney
is likely to be made from metal. At the top of the chimney is a
cap that offers several benefits. For example, during rain, without
a cap, there would be no place for the rain to go other than down
into your stove or fireplace. Not only would you have a hard time
with keeping a fire but also the walls and ceilings of your home
would be ruined. Another problem is that birds and other animals
get down into the chimney to keep warm and build nests, creating a
fire hazard. Finally, metal chimneys are constructed of two or three
layers of metal with either air or some type of insulation in between.
If you do not have a chimney cap, water, and/or moisture gets into
these layers and start creating early failure of your chimney.
Keep in mind that the majority of metal chimneys sold and installed
have a termination cap manufactured by the same company for the
chimney. For this reason, this cap is the best you can get since it
was specifically designed for that particular fireplace chimney.
However, sometimes a retrofit has to be added to help with draft
problems or if the original chimney cap has deteriorated and you are
unable to locate a replacement from the manufacturer.
If your metal chimney is air-cooled using venting on the top, you
need to be sure NOT to close off the venting or a fire could result
from the vents being closed. If this is your situation, you can
purchase a special cap to ensure appropriate cooling.
Standard chimney caps are made from stainless steel, steel, aluminum,
or copper with the most popular choice being stainless steel or steel.
Most chimney caps are designed with a mesh or screen that is another
way of keeping critters out of the chimney. These particular caps
are mounted in several ways. The way most often used is where the
cap is screwed while being spaced around the base angle and the
tightened against the flue tile. If your chimney is not lined or
the flue does not protrude out far enough on the top, the problem
can be fixed by installing inside mounting models. If all else fails,
you should contact the manufacturer for assistance.
If you have a standard masonry flue, there are caps for those too.
The normal options include a standard cap with screen that comes in
black or stainless steel, draft-increasing caps, caps with integral
damper mechanisms, and custom caps for both metal and masonry.