Your Complete Resource for Chimney Caps!

How difficult is it to install a chimney cap and is it a project that should be taken on by the typical homeowner? This question can be easily answered by asking another question. How easily can you gain full access to the top of the chimney? A difficult to reach chimney crown can render the easiest of chimney cap installations impossible for a typical do-it-yourselfer. Even when the chimney top is reasonably or even easily accessible, getting to the top of a chimney can be the hardest part of the job.

Getting to the Top of the Chimney

It’s often been said with regards to heights and ladders: it’s not the fall that is the problem, but rather that sudden stop at the bottom. For some safety tips from the leading authorities on ladder safety, please click here.

Once you have made sure that you are able to safely access the chimney top, here are some tools you will most likely need:

· Cordless Drill (you can use a corded drill, but you may find that the extension cord is cumbersome)

· Phillips Head or Flat Head Screw Driver

· Caulk Gun

· Socket and Socket Drivers

· Tape Measure (for determining the size of the chimney cap that you need)

Not every cap will require all of these tools. Here’s a quick summary of how each of the different style chimney caps are installed -

Single Flue Cap – A single flue cap sets over a flue tile like a shoe box lid. You simply seat the cap on the flue tile and tighten the bolts. You will tighten the bolts using either a screw driver or a socket set.

Top Mount Chimney Cap – This style cap is secured to the top of the chimney using masonry screws. First, you seat the chimney cap in the appropriate position and then mark the position of the holes with a marker. Then remove the cap and drill the holes. Reseat the cap and then secure it using the masonry fasteners, which are typically provided by the manufacturer of the cap.

Outside Mount Chimney Cap – These caps have skirts that hang down over the side of the chimney. If installing on a 2×4 wood construction chimney, you will screw through the skirt until you tap into the wood under the chimney’s finish exterior. Provided you are fastening to a brick and mortar chimney you should line your hole up with a mortar joint and secure this cap using masonry fasteners into the mortar joint. You can fasten into the face of a brick or stone, but drilling into this material is difficult and time consuming.

Who to call if you decide you need a professional to do the job for you:

· Roofers – These contractors will have the equipment and tools to get the job done.

· Chimney Sweep – From top to bottom these professional will be a great resource for chimney caps and more. Find a pro sweep at: www.csia.org

· Handyman – Installing a chimney cap is a quick project that most will be glad to handle for you.

You may be wondering why single flue chimney caps and multi flue chimney caps have two options for mesh thickness. Standard mesh thickness for chimney caps is 3/4". Most chimney caps come with an option for a smaller mesh of 5/8". The mesh screen serves two functions. First, it keeps rodents and birds from entering into the chimney while still allowing for the chimney to exhaust properly. Secondly, it serves as a spark arrestor, not allowing sparks and embers to escape from the chimney and into the environment where it could cause a fire.
Many localities – primarily California, but also in other areas around the nation – have spark arrestor codes that call for 1/2" spark arrestors.

The California state building code calls for such spark arrestors on all new construction. Other California codes call for it in "wooded areas" or "within 200 feet of wooded areas" and when it comes time to sell your home, you can also bet the inspector will require you to update your chimney cap to comply with the spark arrestor codes.
To make such a reduced spark arrestor that does not clog, chimney cap manufacturers follow the interpretation that a sphere larger than 1/2" in diameter should not penetrate the screen. This is wording the National Fire Protection Association uses, as well as the one being referred to by several California localities.

Thus, the spark arrestor screens on these chimney caps measure 5/8" from center to center, but still won’t let a 1/2" sphere through. This makes them somewhat clog resistant while still meeting major code interpretations.
You can check your local building codes to see what mesh thickness is required in your area.