Chimney cap, chimney vent, chimney pot, chimney cowl and chimney shroud are all various structures on a chimney top added to the top of your chimney pipe, chimney flue, stove pipe or even chimney crown. The chimney crown is the flat top of a chimney usually finished with cement or mortar and is ideally sloped to shed water. A fireplace chimney is typically constructed from brick, clay, masonry, metal or fireproof material. Often times there is just a metal chimney pipe or chimney flue that is encased in a fireproof material or else is double wall insulated shielding adjacent flammable building materials. Chimney vents or stove pipe vents vent fireplaces, wood stoves and heaters and provide proper draft. The chimney vent opening might be nearly flush with the chimney crown or else the chimney pipe or chimney flue will protrude out. Stove pipe chimney vents are also found protruding out of the top of roofs. Chimney pots positioned on chimney tops, look like small smoke stacks and functionally extend the length of a chimney. Chimney pots may therefore improve a chimney's draft inexpensively. Whether it is a metal chimney vent, masonry chimney or chimney pot or other chimney material, there is a need to have some sort of termination or cap on the chimney top, to keep rain, birds and critters out of your chimney, chimney pipe or chimney flue. Without a chimney cap, rain water might run into your fireplace, stove or heater and additionally leaks from seams or cracks in the chimney might also damage adjacent walls and ceilings. Also build up of rain and moisture inside your chimney often produces a pervading chimney or smoky smell inside your home. Birds, raccoons, squirrels and other small animals might enjoy the warmth of your chimney, set up home there and clog it with their nests or bodies. So chimney caps often have screening, mesh or lattice work to cover openings. Chimney caps may also protect a chimney crown by shedding rain water and ice. Chimney caps with metal mesh or screening may also perform as a spark arrestor to protect adjacent roofing, walls and ground areas from sparks or embers that may exit from a chimney. Finally, chimney caps may also be purposefully designed to control, preserve or improve upon a chimney's draft. Many chimney caps are made of metal including stainless steel chimney caps, copper chimney caps, aluminum chimney caps and the ever common black painted galvanized steel chimney cap. Standard type chimney caps have a simple sloped roof to block most of the falling rain and mesh sides to block birds, small animals. Some employ tighter screening to also neutralize sparks. They are designed to simply clamp on to round, square or rectangular chimney flue pipes with screw fasteners. Round versions may also provide protection for exposed chimney pots. More expansive, elaborate chimney caps, such as chimney hoods or chimney shrouds, provide a decorative architectural feature and protect more of the chimney top crown.
Chimney pots are most often seen in Tudor architecture and sometimes with Colonial, Victorian and Row Houses. Chimney pots were usually made from clay (terra cotta) but now are also made from metals. New pure copper and weathered reddish brown copper chimney pots are shown above, along with stainless steel and mill finish aluminum pots. Chimney pots are often open at their top, and while a separate protective chimney cap for use on top of chimney pots can be used, even better, a cleaner design like the ones pictured above with their own integral cap and screening. New chimney pots create a certain architectural style or may replace worn out or broken chimney pots to preserve that look. A chimney pot or variation thereof may also be used when you wish to extend the height of your chimney to improve upon insufficient chimney updraft. Some chimney hood or shroud designs also increase effective chimney height.
If you experience too much downdraft into your chimney from consistent high winds or substantial amounts of air deflect off of adjacent walls, tall trees, buildings or hills, then you may need to limit or block excess air being pushed down into your chimney. Passive shrouded chimney cap devices exist that work to limit deflected air or high winds from being driven down into your chimney. They work to block winds from the top and sides, allowing air out only from vents near or on the bottom. There is also a directional chimney cowl - chimney cap, which rotates to align with the wind, to block it and prevent a downdraft of air into your chimney pipe or chimney flue. A turbine chimney vent spins with the wind to draw air upwards and counteract downward air pressure. A downdraft problem may be severe enough that extending a chimney using chimney pots or chimney shrouds or using other passive draft enhancers may still prove insufficient. In this case, there are sources of chimney fans available, which mount inside your chimney and induce upward drafts using variable speed motors and paddle fans.
Chimney caps serve important functional purposes, yet may also provide a very decorative and distinctive architectural feature to your home. Your chimney top and chimney cap are typically at the very highest point of your home and where better to make a crowning statement to distinguish and accentuate your home.
* The pictures above of custom chimney caps, chimney pots and chimney vents, provide courtesy of Rutland's architectural copper and metal work craftsmen. If you can dream or imagine it, Rutland's accomplished coppersmiths and custom metal fabricators can create it. View more of Rutland's many Chimney Cap Designs.