Different Types of Chimney Caps: What You Should Know

Chimney caps are designed to protect the flue opening at the top of the chimney from damaging rain and snow. Some types of chimney caps go even further in their protective abilities. Let’s look at the two main types of chimney caps.

Chimney Cap Installation in Amherst, NHGeneric chimney caps

This type of cap adds a solid layer of protection for the flue pipe(s) that extend from the top of the chimney. Well-designed caps not only block water, which could lead to extensive masonry, liner and component damage, but they also prevent larger hot embers and sparks from exiting the flue and landing on the roof.

Generic chimney caps cover only the flue opening. That’s where their protection ends.

Custom outside mount chimney caps

Like generic caps, outside mount chimney caps prevent water from getting into the flue and keep sparks from jumping out onto the roof. They also protect a very critical part of your chimney system: the chimney crown.

Chimney crowns are cement coverings that seal off the entire top of the chimney beyond the extended chimney liner or pipes.

Crowns can become cracked over time, and when this happens, water can infiltrate the cement and cause more extensive damage.

When water freezes, it expands, pushing against the interior cement of the crown and breaking it apart. It doesn’t take long before water is able to bypass the damaged chimney crown and begin to erode the masonry below it. The result can be a seriously damaged chimney structure that is unsafe to use.

A sturdy outside mount chimney cap is the only way to keep water and snow from seeping into a cracked crown and causing decay. Outside mount caps cover the entire crown and provide a complete level of protection. If crown damage needs to be addressed at any time, your chimney technician can easily remove the custom cap to get to the problem areas.

Chimney Cap installation in Concord NHWhy you need a chimney cap

As we noted, both styles of chimney caps serve as barriers to incoming water and outgoing sparks. They also provide another very important protection: keeping out debris.

If you operate your chimney without a cap, all manner of falling tree debris can wind up in your flue and create a drafting obstruction. Additionally, many types of small animals such as birds and squirrels love to build nests inside chimneys. All these obstructions can cause smoke and deadly carbon monoxide to back up into the home.

Professional chimney repair technicians and chimney sweeps will all tell you that each part and component of a chimney system works in tandem with all the other parts to keep the chimney safe and operating at peak capacity. Damage to any element within the system can lead to extensive damage throughout.



For this reason, it’s a smart idea to schedule annual chimney inspections and chimney sweep services from technicians who are certified through the Chimney Safety Institute of America. This is the best way to ensure that your chimney is free of damage and safe to use.

Learn more about the benefits of custom outside mount chimney caps by calling the chimney pros at Black Moose Chimney & Stove of Antrim, NH. We’re here to keep you warm and safe. Reach a certified chimney expert at (603) 525-7905.