Chimney Cap Installation: A How-To Guide

Updated: Oct. 04, 2023

DIY chimney cap installation will help you keep out unwanted stuff like smoke, odors, critters, and more.

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You don't want water, debris and critters getting into your chimney, do you?

Tools Required

  • Cordless drill
  • Crimper

Materials Required

  • 1-in. self-drilling sheet metal screws
  • Rain cap

If you’ve ever watched the smoke rise up out of a chimney, you may have wondered what keeps stuff from falling into the chimney. After all, rain and critters climbing down there can cause all kinds of annoyances and serious problems. Fortunately, there is a simple, but essential, component to every chimney that takes care of those potential problems: a chimney cap.

What Is a Chimney Cap?

A rain cap functions as a safeguarding apparatus affixed to the top of a chimney or flue, with the primary purpose of preventing infiltration of rain, debris, and animals into the chimney framework. A rain cap vital for upholding the efficiency, safety and extended lifespan of the entire chimney system.

They are typically fabricated from robust materials such as stainless steel, galvanized steel, or copper and designed to include a mesh or wire enclosure that facilitates the ventilation of smoke and gases while obstructing the entry of larger objects. Moreover, the cap’s structure, including its shape and mesh composition, serves to avert direct ingress of rainwater into the chimney, thus protecting the flue liner and the internal walls of the chimney structure.

Chimney caps come in a variety of styles and sizes, so you should easily be able to find one that fits yours.

In addition to making sure you’ve got a cap on it, make sure you’re cleaning your chimney regularly and performing the necessary upkeep and maintenance to keep it safe and functional for your home.

Project step-by-step (2)

Step 1

Check your rain cap for wear

Check and adjust the fit

Slide the new cap into the chimney flue. If the stub section on the cap is too large, crimp it with a crimping tool.

How To Replace A Chimney Rain CapFamily Handyman

Step 2

Level and secure the cap

Plumb the cap so it fits squarely in the flue and secure it with one sheet metal screw. Recheck that the cap is plumb and install two more screws.

High winds, sleet and plain old corrosion can cause a rain cap to break apart, rattle and leak water into your home. If you feel comfortable climbing up on your roof, you can replace the old one yourself for less than $100. That’ll save on labor costs if you hire an HVAC service company to do it.

You can buy a new rain cap and a sheet metal crimping tool at any home center. Flues are usually 5 or 6 in. in diameter, so buy both size caps and return the unused one. You’ll also need three hex-head or Phillips self-drilling 1-in. sheet metal screws and a drill and bit.

Remove the old rain cap and toss it. Select the correct cap and check the fit (Photo 1). Then secure the new cap (Photo 2).

How To Replace A Chimney Rain CapFamily Handyman


Do roofers install chimney caps?

While roofers may be involved in the process when they are working on roof-related projects, like repairs or replacements, chimney caps are usually installed by chimney specialists or masons. These professionals have the expertise to properly assess your chimney’s needs, select the right type and size of cap, and ensure it’s securely installed. So, if you’re considering a chimney cap installation, it’s advisable to consult with a chimney specialist who can provide a comprehensive solution for your specific needs.

How much is a chimney cap?

On average, you can expect to pay anywhere from $100 to $600 for a chimney cap, including both materials and installation. The price can be influenced by factors such as the type and size of the cap, the materials it’s made from (stainless steel, copper, galvanized steel, etc.), and any additional features you might choose, like spark arrestors or animal guards. Custom-made caps tend to be more expensive than standard-sized ones. To get an accurate estimate for your specific chimney, it’s a good idea to consult with a professional chimney service or contractor. They can assess your needs, recommend the right cap for your chimney, and provide you with a detailed cost estimate.

Does a chimney cap reduce draft?

Yes, a chimney cap can indeed reduce draft issues in your home. Draft problems often occur when wind blows down the chimney, causing smoke and odors to enter your living space. A chimney cap, with its design that includes a hood and side vents, helps redirect wind and air currents away from the chimney opening. By doing so, it creates a barrier against downdrafts, acting as a fireplace draft stopper and allowing it to operate more efficiently and safely.