Part 4: Why is My Chimney Chase Cover Leaking?

Part 4: Why is My Chimney Chase Cover Leaking?

The purpose of a chimney chase cover is to prevent water from entering the chimney. A properly fabricated chimney chase cover should never pool water on the top of the pan. Pooling water on the top of the chase will cause inferior steel to rust more quickly. The cover should always shed water off the chimney. Water can sit on top of the chimney cover for days if the temperature is low and with no wind, which expedites the corrosion process.

This first example shows that the chimney cover is attached to the top of the chimney through the top of the chimney cover. You can see a clear line on the cover that is sending water directly to the nail head. When you drive a nail down through the top of the cover, that becomes the low spot on the cover. We all know water will travel downhill and in the path of least resistance. What happens over time is that the top of the chimney expands and contracts with the heat cycles and use of the fireplace in winter. This will cause the nail to pop out, creating a hole in the top of the chimney. If your chimney cover has nails going through the top of the cover, it should be replaced immediately. Fasteners should always go through the side skirt of the chimney cover.

This next example follows the same lines as the previous picture. However, this installer took it to the next level. This installer must have thought the chimney cover was going to blow away. Like we have previously stated, "Nails should not be used through the top of the cover." This amount of nails is not necessary. Even if the nails were driven through the side skirt, this amount of fasteners is way too many.
This next example has no nails going through the top of the chimney. This cover also has no support under the cover. When a chase cover is installed correctly, there is a piece of plywood under the cover with a hole cut in the wood large enough to maintain the proper clearance from the flue pipe. It rained 5 days before this picture was taken. That is how recessed the center of the cover was.
This next example is exactly how a chimney chase cover should not be installed. If you see anything used as a chase cover other than steel, replace it right away. This caused significant water damage to this customer's home. This home was relatively new, only about 10 years old. They had the leak start coming in 4 years ago and one day the bubble popped and they had a significant amount of water entering their home. This so-called chase cover was some type of roofing material, such as a big sheet of tar with asphalt sprinkled on it. The tar started to sag around the pipe and caused a steady drip going into the home. If you have any material on the top of your chimney chase other than steel, replace it immediately.

To cap this segment, if you see water pooling on the chimney cover, the general rule of thumb is to replace it right away.

Article Series: Why Is My Chimney Leaking?

Click here to move on to Part One of the "Why Is My Chimney Leaking" Series! If this article did not solve your issue, we have more troubleshooting articles for you to review.

Here are a few helpful links for the chase covers:

DIY Center

(AKA ‘The Rockford Files’)

From video tutorials to product walkthroughs, we have a variety of DIY resources just for you! Click the button below to view our entire library.


Need Help?

We are here to answer all of your questions




Our 316Ti flexible chimney liner and chimney liner components have passed the rigorous testing at the Underwriters Laboratories with best in class status and are UL Listed. So if you are looking for UL listed chimney liner sold directly to homeowners, then look no further than Rockford Chimney

Customer Testimonials

Back in July you gave me excellent advice re. sizing/purchasing a flue liner for the chimney associated with my wood stove. I'd like to thank you once agai... More

—AE Northfield, MN

A few weeks ago I ordered a chimney liner system for my fireplace insert. Your salesman recommended the liner system plus the insulating blanket. I just wa... More

—AH Happy customer

Just got around to installing my new smooth flexible liner and deluxe terra cotta cap (wow). The quality of your product is second to none. Very pleased an... More

—B.B. from Massachusetts

Thanks so much for the great tech service from Dennis, very knowledgable, friendly and proffessional.Your website is the best, beats your competition by fa... More

—Bill in Knoxville

Sue and Dennis, I received the final part of my order yesterday (the chimney cap that actually fits over the chimney chase). It looks wonderfu... More


Hello, I was shopping for an fireplace insert and called RCS to ask why they were so much cheaper than my local guy, the reply was " we sell thousand of th... More

—Chris, PA.