Many people have a chimney, but few know very much about their inner workings. If you have been lighting fires in your fireplace year after year but have never taken a look inside your chimney, you could have a very big problem. Like anything related to fire, dangers abound when it comes to fireplaces and chimneys and many people are not aware of how simple it is to avoid these issues.

One of the biggest ways to ensure fireplace safety is to have a well-fitted and well-maintained chimney liner. A chimney liner goes inside the chimney to help direct the gases up and out of your house and protect the inside of your house from the heat and chemicals of a fire. Many older chimney liners begin to corrode, causing dangerous gases to leak into the house. And some older chimneys aren’t lined at all. This can lead to the toxic byproducts of fires building up inside the chimney and causing a fire such as creosote. If you are unsure whether or not your chimney has a chimney liner, it is crucial to find out right away.

Even if your chimney has a chimney liner, it is important to keep it updated. All chimney liners will become less effective with use and will need to be replaced between 5-7 years. The exact amount of time a liner can last will depend on the type of material used to make it as well as the type of fires you build in your fireplace and the frequency of use. Also, some older homes have liners that are the wrong size, which can lead to dangerous conditions as well.

Chimney liners are not terribly expensive and there are a number of options when it comes to chimney liners depending on the type of chimney you have. There are number of do it yourself option on the market today that will allow you save money and install a chimney liner yourself.

If you haven’t had a chimney inspection recently, it is an excellent idea to have one because it can be difficult for inexperienced chimney owners to know which dangers to look for. It is also difficult to actually see the inside of your chimney. Many experts recommend an inspection every one or two years to ensure the safety of the fireplace. The inspector will look over the fireplace and chimney from the inside out and can make recommendations on any maintenance or repair issues that need to be addressed.

What is a Chimney Cap?

A chimney cap is a protective covering which fits at the top of your chimney enclosure. They are typically fashioned out of stainless steel, copper, or galvanized metals; and come designed with a mesh screen to inhibit airborne hearth sparks, nesting outdoor animals, and damaging precipitation and debris from interfering with the overall safety and longetivity of your fireplace’s necessary venting system.

Why is it so crucial to keep sparks confined to your chimney liner and these other elements out? While you are toasting marshmallows and sharing intimate discussions by the glow of your fireplace’s hearth, quite a bit more is happening in the venting chamber of your chimney. The sparks produced from burning wood or faux logs will sometimes reach to your chimney’s top, and if not properly stopped, can ignite the flammable material surrounding your chimney wall, such as your roof and house’s construction. And all it takes is one airborne spark. Nesting animals such as squirrels and birds can find a sheltered refuge in your chimney’s top, usually without anyone being the wiser… until it’s too late. A chimney cap prevents them and their detrimental waste from taking up residence, thereby preventing foul odors and the mites that waste brings. Your chimney top is also exposed to rain, snow, hail, and violent gusts of wind; year after year. Without a chimney cap to insulate your chimney from its effects, rain can soak into the mortar joints of your chimney’s construction, thereby loosening the bricks or stone of your masonry chimney. Or if you have a metal chimney, precipitation will lead to damaging rust; thereby rapidly deteriorating your chimney. Violent wind gusts whip leaves and assorted debris into your chimney.

These flammable materials can rapidly suffocate your flue from its necessary fire by-product venting, leading to dangerous chimney fires and downdrafting of the trapped smoke into your home. Buying a chimney cap is a priceless and easy solution to preventing a whole Pandora’s Box-full of natural evils, such as: fire, disease, costly repair, and strife from entering the safe harbor of your family’s cozy home.

Types of Chimneys

The first step in finding yourself a chimney cap is determining what type of chimney your house has. This will determine what type of chimney cap will fit best. The most common type of chimney is a masonry chimney, which is constructed of brick, stone, or concrete. Metal Chimneys or factory-built chimneys are mass-produced, typically come with a pre-fit chimney cap, and must be used with one, due to the fact that metal is less resilient in relation to Mother Nature’s elements. Typically, for masonry chimneys, you’ll find that their corresponding chimney caps come in three basic sizes: 8″ x 8″, 8″ x 12″ and 12″ x 12″, though custom styles and fits are available also.

Types of Flues

Whether you have a masonry or factory-made metal chimney, it is also necessary to determine what type of flue it works from. This can be determined by simply looking down into your chimney’s depths.

Masonry chimneys will have either single or multi flues, and these flues will be either extended or not. The most common is the single flue chimney with an extended flue. This flue will simply and visibly extend out the top of your chimney, allowing easy chimney cap installation and fit by screws which tighten to the flue’s construction. Single flue chimneys without extended flues have a recessed interior flue construction and will require what is called a leg kit or bracket to for installation of your chimney cap. The decision about whether you enlist a leg kit or brackets is yours, but brackets are recommended as they provide more resiliency under varying wind and weather conditions. Multi flue chimneys with or without extended flues will, as the type suggests, have more than one flue (typically two) either protruding from your chimney top or recessed in its interior.

Factory-produced Metal Chimney will have one of three basic types of flue construction: double-wall solid-pack insulated chimney pipe, double-wall air-insulated chimney pipe, or triple-wall air-insulated chimney pipe. Looking down into the chimney, you’ll see either two or three layers or walls of metal. If there is a metal cap or insulation material between these layers, you have yourself a solid-pack insulated flue system. If there is nothing but air between your flue walls, it is an air-insulated flue system.

Measuring

After determining what type of chimney and what type of flue you have, the next step is measurement of the flue system. Whether single or multi, extended or recessed, you will almost always need to know the precise width and length dimensions in order to accurately fit your chimney for a cap. Take the measurements a couple times to ensure accuracy, because being just a fraction of a size off, will negate all the purposes you’ve enlisted your chimney cap to demonstrate.

Masonry Chimneys:

· For a single flue with an extended flue: measure the width and length of the outside parameters of the flue, and match these to a specific chimney cap size.

· For a single flue without an extended flue: measure the width and length of the inside parameters of the flue, match to a specific chimney cap size, and order the corresponding leg kit or brackets.

· For multi flue systems with or without extended flues: measure the total outside width and length of the combined flues. If your multi-flue system has one or more extended flues, you must next measure how far the highest flue extends out the top of the chimney. It is crucial when choosing a cap for these systems that you depend upon the measurements of your total flue system, as well as the flues’ height measurements to see how deep your chimney cap should be.

Factory-made Metal Chimneys:

· For a double-wall solid-pack insulated flue system: measure the diameter of the inner pipe. Then, measure the diameter of the outer pipe. The inner dimensions will be used to secure the proper fit, while the outer dimensions will give a wider secondary cap protection for your flue.

· For a double or triple-wall air insulated flue system: measure the diameter of the inner pipe. Then, measure the diameter of the outer pipe. The inner dimensions will be used to secure the proper fit, while the outer dimensions will give a wider secondary cap protection for your flue.

Materials

Chimney caps come in a variety of materials depending on your aesthetic, function, and cost preferences. Galvanized metal flue caps are the most cost-effective and simple choice; but provide basic function without regard to aesthetics, will rust, and won’t last past the short-term. Stainless steel chimney cap construction is more middle-of-the-road cost-wise, and subsequently offers a more gratifying visual appeal, and will last much longer through varying elements and time. Copper chimney caps are the most expensive choice, but because of this offer: a hard-enduring quality, can be weathered naturally or coated with a special copper protectant to maintain the original color and shine. Stainless steel and copper constructed chimney caps do, more often than not, come with an extended warranty; and are the best way to go in the way of your chimney’s longetivity and your home and family’s safety.

Chimney Cap Types

Chimney caps also come in a variety of functions according to your cap preferences. There is the standard chimney cap which typically includes a screening material to further ward off elements and critters, is the most cost-effective, comes in a variety of materials, and takes care of your most basic chimney needs as far as insulation and protection is concerned. Draft increasing caps or vacuum chimney caps are more specific to a chimney that has difficulty, for one reason or another, drafting smoke up and out of your home. These chimney caps produce a stronger updraft, and are most often used with metal chimneys, though those with masonry chimneys can employ specific manufacturer adapters. There are two different options to cure this common chimney affliction. You can either employ what is called a flue stretcher which will extend the length of your flue and remove it from the influence of nearby or dual chimneys. This is a great option if you live in a dense city or have multi-floor fireplaces. Another option is a device which will decrease the downdraft by deflecting it within special cap fins, and subsequently suck excessive smoke out of your chimney. You may opt for a cap with an integral damper mechanism to replace a missing or loose-fitting damper system in your chimney. This type of chimney cap, once in place, will cap the previously wasted energy, restore the necessary damper functions, and insulate your home from the elements. Most come complete with a lever you’ll need to install on your fireplace wall, which activates effective use of the damper. Typically, those with older fireplaces will enlist these dual-purpose caps to gently restore an older fireplace.

If you have an older home chances are that your chimney is going to be unlined. Over the years the interior of the chimney bricks and mortar deteriorates because of the cooling of exhaust gases produced by heating equipment. As the exhaust gas cools it creates condensation and can ultimately deteriorate the chimney to a point where exhaust gases escape the chimney. There is hope though, you can install a retrofit chimney liner.

There are two main ways to install a chimney liner. One is to install a cement liner by using an inflated balloon that is inflated while down the length of the chimney. This creates a tube or void in the center of the chimney. Mortar material is then poured around the exterior of this balloon. When the material has dried and set the balloon is removed and a solid liner then exists around the interior perimeter of the chimney.

The second method is to use a flexible metal liner which is basically a tube of stainless steel that is fed from the top to the bottom of the chimney. This type of liner can be used for boilers and furnaces but can not be used for wood burning fireplaces or wood stoves. Professional installation is recommended but if your ambitious you may want to perform the job yourself. A metal scaffold has to be installed around the chimney and working high off the ground is required. Do not attempt the installation if you are not able to aquire and erect a proper scaffold system.

The chimney must be professionally cleaned before the liner can be installed. Any missing and chipped mortar should be replaced. It is a good time to tuck point the chimney because you or a chimney professional already has the scaffold erected. It will also be less expensive if you incorporate a tuck pointing with the other work being performed.

The flexible stainless steel chimney liner is installed as follows. You will need the help of another person while performing this installation. Drop a long length of medium thickness line down the length of the chimney. Attach the lower end of the flexible chimney liner to the opposite end of the weighted line. This will allow an assistant to gently pull and guide the new liner down through the length of the chimney. While your assistant guides the chimney liner down you are simultaneously feeding the flexible chimney liner down the chimney.

After the chimney liner is completely down the chimney the end has to be connected to a plate which is provided by the manufacturer of the metal liner. The plate will be situated over the hole in the chimney and the smoke pipe from the heating appliance will connect up to the plate. This will allow the heating appliance to vent exhaust gas up through the new metal chimney liner. Seal all gaps where the plate meets the chimney with refractory mortar to tightly secure the plate.

The metal chimney cover can now be installed at the chimney top. The end of the flexible liner will attach to the bottom of this cover so the exhaust gases can escape. The last step is to install the metal chimney hat at the flue outlet at the very top of the chimney. The chimney hat is secured by four screws positioned around the exterior of the chimney hat.

The installation of a new chimney liner is challenging but it is possible for a motivated individual to take on the project. The use of a retrofit cement liner should be left to a professional chimney mason or sweep. Before you attempt the installation a professional chimney sweep should be called in to make sure the structure of the chimney is stable and can accommodate a chimney liner.