With so many options available, shopping for chimney caps can get somewhat overwhelming. Let's try to answer some of the most common questions to make it just a little easier.
Are Chimney Caps Necessary?
A chimney cap is essentially a chimney cover that serves several imperative purposes. Capping a chimney helps prevent water damage and other destruction to your chimney and fireplace from harsh weather, such as rain and snow. It can also drastically reduce the risk of house fires or even wildfires by preventing sparks from escaping out through your chimney.
Chimney caps also save you money. They are placed on the top of the chimney, on the exterior. When your fireplace or stove is in use, the chimney cap allows smoke and ventilation to draw properly while keeping debris like leaves and sticks from entering the chimney. These objects are flammable, but they can also be wet which creates moisture inside of the chimney which can lead to smoky fires, a rusty damper etc., or other water damage.
Chimney caps also keep birds, squirrels, and other animals from making your chimney their home or even making their way into your home. Think of a chimney like an open window, without a window covering of some sort, there is nothing in place to prevent them from coming right inside.
Chimney caps are available in a large selection of sizes and are sure to keep your fireplace operating safely and efficiently.
To learn more about how chimney caps can protect your chimney from outside dangers read our article, How a Chimney Cap Protects Masonry Chimneys from Potential Damages.
What Chimney Cap Do I Need? Masonry, Metal, Custom, Decorative, 6-inch, 8-inch?
Single Flue Caps
Let’s start talking about a single flue chimney with an extended flue. This is going to be the most common chimney style. It is also going to be the easiest cap to measure for. You are simply going to measure the width and the length of your extended flue and make sure that you are measuring the outer diameter of your extended flue.
Single flue caps often mount with pressure screws and a flue size ring that it will mount to. For example, an 8”x 8” cap will fit flues made from 6.5” to 8” in both widths and lengths.
Now if you have a single flue chimney but the top of your flue doesn’t extend out enough for a top mount cap or it’s flushed with the crown, you’ll want to use a flue mounted cap. You’ll just need to use a chimney cap that will allow the cap to be held from inside of the flue.
If you live in a very windy area, we recommend that you use a top mount bracket that is going to allow it to attach directly to the crown of your chimney rather than fitting inside. It will be a stronger connection. When you are measuring for this, you will need to measure the outer length and width of your flue and then you’ll have the measurements that you need.
If you need a single-flue cap, you again will need to select the correct size and then decide on the type of finish you would like. We offer them in black, stainless steel, and copper finishes.
Round Chimney Caps
Now let’s say you have a extended flue chimney but the extended flue on the top is going to be a round or oval flue, so then you will need to use a top mount style cap. If your flue is oval or round, make sure that you are measuring the total crown width and length. You will also need to measure the width of the area surrounding the flue and the height of the flue if it is extended.
If you need a round chimney cap, you will need to select the correct diameter first and then determine which brand is best for you. You will need to make this selection based on your budget for a chimney cap and the quality of cap that you would like. We carry stainless steel caps and air-cooled caps. We do recommend that you choose a brand that is the same as your chimney pipe, as these components are made for one another.
Multi Flue Caps
The last style chimney that you may have is a multi-flue chimney. If you have a multi-flue chimney this will always require a top mounted cap regardless if their flues are extended or not. The measurements that you will need for this type of chimney are the total crown width and length, the length of the area surrounding the flue as well as width and the height of the tallest flue sticking out.
To avoid draft problems, the cap must be 5” taller than the tallest flue.
Multi-flue caps can be sized to fit just around the flues or to cover your entire chimney crown. You can save on caps by sizing it to the minimum amount needed and cover just the flue especially if you are going to be choosing an expensive material like copper. Other materials available include aluminum and stainless steel. For the best protection and best looking cap, you will want to cover your entire chimney crown and most people do choose a full-size cap.
If you need a multi flue cap, you will want to first choose the correct size that you need. Then choose between one that is already assembled, or you can choose a knock-down version that you can assemble on site. These types of caps are made to attach right to your chimney crown.
Other Options There are many options that are available to you! For example, we have decorative chimney caps and chimney surrounds, like specialty chimney caps, stainless steel and copper options for that shiny finish or galvanized steel for an affordable but effective option. Having draft problems? We have an extensive selection of down draft solution caps which can help control smoke that may go back into your home when burning, especially helpful in excessively windy areas. Another category of caps is our top sealing damper caps, with built in dampers to help reduce heat loss.
We also offer animal guards, which is a mesh covering that can be installed around other vents in your home to prevent animals from nesting in them. As you are evaluating your chimney and what cap is best, you may also want to look around the rest of the exterior of your home and determine if you need to install animal guards anywhere.
We recommend checking your local building codes as a spark arrestor, and possibly a specific size mesh, may be required with your chimney cap.
How to Measure for a Chimney Cap?
Choosing a chimney cap can be a daunting task but fortunately, determining what size chimney cap you need isn’t as difficult as what it seems. Grab a tape measure, a pencil and paper, and a ladder. You will need to get up on your roof to physically inspect and measure your chimney.
We have created a video to help, check it out here, What to Measure Before Purchasing a Chimney Cap
Don't forget to check your local building codes, so you can plan for mesh if it is required.
Which Chimney Cap Material Will Suit You Best?
Galvanized Chimney Caps - Galvanized Steel - These galvanized chimney caps tend to be one of the most inexpensive options, however, are prone to rust or corrosion in most environments and may need to be replaced sooner than its alternatives.
Aluminum - Aluminum is another more affordable option but like its galvanized steel counterpart, it may not last as long due to potential corrosion.
Copper - Copper caps are usually a decorative favorite. Not only do they offer durability but rather than rusting they oxidize in a blue green-finish for an aesthetically pleasing curbside appeal.
Stainless Steel - Stainless steel is probably one of the best and most popular options. It is the most durable and will protect against harsh environmental elements like wind and water plus it avoids rusting. Stainless steel offers a pleasant shiny finish or can come in a painted black finish.
How to Install or Replace a Chimney Cap: Installation and Replacement
Check out this video, for an example of how to mount a masonry chimney cap. This will help for either installation or replacement.
A Prefabricated chimney cap's installation could differ slightly from that of the masonry chimney caps, so refer to the user manuals included with the chimney system and cap for direction.
Please note, improper installation can result in downdrafts and other draft problems, especially in windy areas.
Besides your chimney cap, you will also need silicone adhesive for your installation. Silicone adhesive will allow you to seal the cap in place and they are rated for high temperature, so not just any type of silicone will work.
Always refer to your local building codes prior to mounting your chimney cap in case any requirements need to be considered.