What Chimney Caps Do & Why You Need One

An often-overlooked but critically important part a chimney system is the top-mounted chimney cap. These devices can cover just the flue opening or the entire top of the chimney to provide year-round protection from a number of things that can cause serious damage to your chimney.

Here’s a quick overview of the different types of chimney caps and how they can safeguard your chimney.

full width chimney cap, fairfield ctTwo types of chimney caps

One type is technically just a flue cover. Typically made of metal with mesh sides, it fits securely over the flue opening. A proper chimney cap is a full-width component that covers both the flue opening and the concrete chimney crown.

Chimney technicians recommend at least a flue cover, but most prefer using a custom full-width chimney cap. Here are four reasons why your chimney needs protection of a chimney cap.

To block the rain and snow

Chimney caps create a wide rain/snow barrier over the flue opening. With a full chimney cap, falling rain and snow won’t come close to the opening of the chimney flue. Water inside the flue can lead to big problems such as:

Chimney liner deterioration

Over time, moisture can begin to damage a chimney liner, which is in place to protect your chimney’s interior masonry and adjacent home building materials from intense heat, flames and acidic compounds.

Damage to interior chimney masonry

Water and bricks don’t mix. Bricks are porous and absorb water, and bricks and mortar often have small cracks that water can infiltrate. Chimneys regularly suffer major damage because of water intrusion.

Mold growth

Standing moisture in the dark, poorly ventilated flue is the perfect recipe for the growth of harmful mold.

Offensive odors

Water mixed with soot and creosote will cause strong odors to flow down into your living spaces.

To protect the concrete chimney crown

Only a full-width cap will protect the chimney crown from water damage. Built with concrete, chimney crowns are prone to cracking, and when water gets into those cracks, the entire crown can be destroyed.

Once the crown is compromised, water can seep inside and begin deteriorating the bricks below the crown and filter down into unseen areas of the chimney, where masonry damage, mold growth and eventual rotting of adjacent home building materials may occur.

full-width chimney cap installation, rockaway njTo keep animals and debris out

Chimney caps are your best defense against squirrels, birds, rodents, raccoons and other small animals, some of whom build nests inside chimney flues and often die, unable to escape. Tree debris such as leaves, twigs and falling fruit is another problem.

All this material will create a drafting obstruction, causing smoke and deadly carbon monoxide to back up into your home’s air. The material also can serve as fuel for a chimney fire.

To contain sparks and embers

A good chimney cap will help to keep rising sparks and embers from popping out of your chimney and landing on your roof or in your yard. It also will contain the larger amount of fiery debris produced during a chimney fire.

Get the right chimney cap for your chimney

National Chimney Service installs beautiful full-width chimney caps for our customers throughout Morris County, NJ, and Fairfield County, CT. If your chimney has no cap, or if the one you have is damaged and can no longer do its job, call us at 800-631-6177.


Use an Experienced, Established Chimney Sweep Company!

Don’t take chances with uninsured, novice, roofers, unregistered business, no workman’s comp.
Our pros have to know what they’re doing when they put their heads up a chimney and to do that, chimney sweeps obtain specialized training and have years of experience in the field.