Mark McCullough shares his thoughts on chimney caps, how homeowners can decide if and when they need one, and available options.
Are Chimney Caps Necessary?
It depends. When a new chimney is built, the mason constructs it in such a way that it does not need a cap. But, over the years, branches and other obstructions could make a cap necessary to protect the flue from being clogged. Also, in the case of a fireplace chimney, a cap will prevent rain from falling down the chimney and splashing in the bottom of the fireplace.
There are Two Different Types of Chimneys
There are two chimney types: a fireplace chimney and a mechanical chimney. The fireplace chimney is for rising smoke while the mechanical chimney is for exhausting gasses from boilers, furnaces, water heaters, and other fuel-burning appliances. These flues are separate but may exit a building in the same chimney structure.
Chimney Cap Functions
Chimney caps have several functions. For one, they protect the chimney from a downdraft, or air rushing down the chimney flue. They’ll also protect the chimney from direct rain. The screens on the sides of the cap protect against animals like squirrels, raccoons, and birds from obstructing the chimney or entering the home. It also prevents branches, leaves, and twigs from falling in.
Material Choices
There are a few different material choices when it comes to chimney caps. Powder-coated galvanized steel is the most affordable. Stainless steel is more durable but more expensive. Copper is even more long-lasting than stainless steel, but also very expensive.
Installing Chimney Caps
Installing a chimney cap is very simple. As long as the chimney cap is the right size, it will sit directly on the flue liner. Then, there are bolts in every corner that need to be tightened. Once the bolts are snug, the cap is installed.
When Flues are Too Close for Separate Caps
When two flues are too close to each other for separate caps, there are large units that cover the entire chimney and bolt to the concrete cap. These caps cover both flues at once to protect the chimney from any potential issues.
Resources
Mark discusses several size options for chimney caps depending on flue size, including:
As well as collapsible options that are easy to assemble.
