Chimney Components
Chimneys are designed to give smoke and byproduct gases like carbon monoxide a clear path out of the house. To work, it must be free of cracks and holes that can allow corrosive creosote to ooze in.
Chimneys also need to have a certain height to be able to draft properly. This is because hot combustion byproducts mingle with cool air to produce condensation.
Flues are the passageways inside chimneys through which smoke and gases rise from fireplaces, wood stoves, wood pellet stoves, gas furnaces, and other combustion appliances. They allow the hot gases and smoke to escape safely from the home, and they also help to heat the house.
Chimney flues are traditionally made from clay, and newer chimneys are often lined with steel or metal, which allows the fire gases to flow more easily. This is because the smooth surfaces of these materials cause less friction than the rough surfaces of brick and mortar.
The problem with many chimneys occurs when the flue becomes blocked. This can be caused by a closed damper that accidentally or intentionally shuts or by a chimney cap that was installed incorrectly. Other causes include a chimney fire that cracks the flue, blockage from animal or insect nests, and other structural damage.
Because the flue is such an important part of a chimney, it is critical to have one that works properly. This is why having your flue inspected on a regular basis is so important. Your chimney should be inspected at least once every year before you begin using it for fires, and more frequently if you use it regularly or burn unseasoned firewood.
A poorly functioning chimney will often create problems such as backdrafting. This happens when hot air that wants to leave the chimney cannot get through due to negative air pressure in the room. The air then reverses course and enters the home, carrying harmful chemicals like soot and carbon monoxide into living areas.
You can help prevent flue problems by opening the chimney doors for a few minutes before lighting a fire. This will warm up the air in the flue, allowing it to go up the chimney more easily. You can also try placing a large, rolled-up piece of cardboard or tightly rolled newspaper under the damper before starting a fire. This will keep the damper from closing too soon, which can make it harder to start a fire and create a draft.
Smoke Chamber
The smoke chamber serves to help funnel hot air and byproducts from your fire up into the chimney flue. It’s designed to look like an upturned funnel, ensuring a swift journey for the smoke and gases. Unfortunately, improper construction and a lack of maintenance can lead to issues with the smoke chamber that are harmful for your chimney and home.
Most older homes built their smoke chambers with jagged steps (a process known as corbeling). These stepped masonry steps create rough surfaces that prevent byproducts of combustion from flowing smoothly up into the chimney and flue. Moreover, the heat that these rough surfaces receive can erode and damage masonry joints and bricks over time.
Over time, the many sharp angles and factory-made holes found on a corbeled smoke chamber’s walls can become the perfect collection points for creosote. This flammable byproduct of wood combustion can build up in these areas and eventually ignite a chimney fire. The resulting soot and carbon monoxide can then be drawn back down into the fireplace and into the living spaces of your home, posing a significant safety hazard to your family.
Chimney fires caused by the deterioration of your chimney’s smoke chamber aren’t just annoying; they’re dangerous! Creosote accumulation within your smoke chamber can also make it difficult for the chimney to draft properly, which is a major fire hazard.
Annual chimney inspections and cleaning services, including a thorough chimney sweep of your smoke chamber, can prevent these problems and ensure that your fireplace and chimney function safely and efficiently.
When it comes to your chimney’s smoke chamber, parging is a simple and effective repair that can significantly improve the function of your chimney system. This specialized chimney service involves smoothing out rough areas of your smoke chamber’s surfaces with refractory mortar, a material that is formulated to withstand high temperatures and resist heat degradation. When applied by a skilled and experienced chimney technician, this process can reduce your chimney’s draft problems, decrease the risk of chimney fires, and ensure that your fireplace and home are safe to use.
Throat Damper
Despite the fact that it is one of the most overlooked chimney components, the throat damper can have a huge impact on your fireplace and home. If you have a throat damper that has lost its airtight seal, it can create a negative pressure situation that affects your draft and drafting efficiency. Fortunately, this is an easy problem to fix by having it repaired or switching to a top-mount damper.
Throat dampers sit right above the firebox and have metal flaps that are opened or closed with a chain. While they do a good job of blocking the flow of outside air, they aren’t as efficient as top-sealing dampers. Throat dampers have a problem with moisture and are often susceptible to warping and rusting over time. Unlike throat dampers, top-sealing dampers are constructed of stainless steel and don’t have any metal-on-metal contact. This means they are more durable and can provide a better seal.
The best part about top-sealing dampers is that they are completely airtight when closed. This helps keep heat, cold, and outside moisture from flowing through the flue system and into your home. This can save you money on heating and cooling costs.
Throat dampers can also let outside air and water leak into the flue system. This can cause mold, rust, and other problems. Top-sealing dampers can prevent this from happening because they seal off the throat and the flue system with a silicone rubber seal.
Many homeowners have throat dampers but are converting to top-mount dampers. Changing over from a throat damper to a top-sealing damper can be a fast and affordable process that can be done as part of a chimney repair or chimney cleaning service.
While a throat damper can be opened or closed by pulling a chain or using a handle, a top-mount damper is operated with an easy-to-use, spring-assisted handle. It can be opened or closed at any time of year and is convenient to have handy. It’s also a great way to help prevent animals, debris, and moisture from entering the chimney while it’s not in use.
Chimney Cap
Chimney caps come in a wide range of sizes and types to suit most any chimney. Some are made from galvanized steel, aluminum, stainless steel, or copper. Each type offers a different combination of durability and curb appeal. Regardless of the material, most chimney caps are designed to keep rain out and sparks and embers in. A chimney cap also helps reduce energy costs by keeping cold drafts out.
Without a chimney cap, cold winds can blow smoke, embers, and ash back into the house, which causes a loss of heated air. These downdrafts also increase your energy bills since you’re paying to heat cold air. With a chimney cap, these downdrafts are redirected into the chimney, where they’re heated, and the warm air is vented out the top of the flue.
A chimney cap will also prevent water from entering the chimney. Rainwater can cause a variety of problems, including damage to the chimney liner and damper, mold and mildew in the fireplace, and corrosion on the chimney. A chimney cap keeps rain out of the flue and down the roof, where it’s safely diverted to the gutters.
The most common kind of chimney cap is the standard one that lies flush with the top of the flue and is screwed into place. Standard caps include screens to keep out birds, squirrels, and other small animals. They also help catch big sparks that could drift from the fire and strike the roof of the house, causing a chimney fire.
Another popular type of chimney cap is the adjustable-flow chimney cap, which has an opening that opens and closes to control how much air enters the chimney. This type of chimney cap is usually made from galvanized steel or stainless steel, and it is often backed up by a lifetime warranty.
There are also a number of ways to secure a chimney cap, including legs that slide into the flue and brackets that attach to the chimney’s crown. When choosing a chimney cap, measure the length and width of your flue to find a model that will fit perfectly. If you have multiple flues, be sure to get a multi-flue chimney cap that can cover all of them.
