There are various ways to top off your chimney. Of course, you may feel that your chimney looks just fine the way it is. But different sorts of tops can have different functions which you may find value. There are two basic devices that can be set on top of your chimney-chimney tops and chimney caps. Each has its use.
Chimney tops may seem purely decorative. And they certainly look nice. Not as popular in the United States, these tall, slender structures can be seen throughout Europe. They are simple or ornate clay cylinders that stand atop a regular brick chimney. They add a small decorative touch to the roof that can be surprisingly enjoyable, especially when all the roofs around have similar structures.
But a chimney top isn't just for decoration. The purpose of these devices is to extend the length of the chimney slightly, thus increasing the draft. This can help ensure that even on cold days, the smoke flows up and out rather than down and into your home.
Whether you need to improve that draft or not, you may like the idea of having a chimney top on your home. You can find them in simple rounded or squarish designs as well as more complicated shapes with figures of animals and people in relief around their perimeters. You're sure to find something that matches your tastes and the architecture of your home.
You may want to find a chimney top that can be fitted with a cap in order to get the benefits listed below and have the best of both worlds.
Chimney caps are a necessity for metal chimneys and a good idea for any chimney. A metal chimney is just the right size to accommodate a bird's nest. Whether you love birds or hate them, you don't want one building a nest in your chimney. If trees overhang your roof, leaves and branches can get lodged in your chimney, creating an obstruction. And whenever it rains or snows, your chimney can become a conduit for water that can cause rust, wood rot, and other structural problems.
A simple chimney cap can take care of all those problems while still allowing your fireplace to draft properly. In fact, you can find a "draft increasing" or vacuum chimney cap which will help to create a stronger updraft than your chimney would on its own. If you decide on one of these sorts of caps, avoid the mechanical ones that use wind vanes or spinning turbines. The creosote from your fire can gum up the works and make these caps more trouble than they're worth.
You can also get a chimney cap with a damper mechanism. This is useful as a second line of defense (or third if you count the glass doors) to keep your home airtight. You don't want heat escaping your home when the chimney isn't in use. However, you will have to remember to open that damper before you start your first fire of the season.