Stainless Steel Chimney Liners: Frequently Asked Questions
- Can my fireplace be an efficient source of heat, and is it environmentally safe?
- How do I make my wood burning fireplace more heat efficient?
- What causes chimney and fireplace smells?
- Why does a chimney deteriorate?
- What is creosote and why should I be concerned about it?
- What is a chimney relining system?
- What are the benefits of a stainless steel chimney liner?
- What is the difference between rigid and flexible liner kits?
- Do I really need to insulate my chimney liner?
- Can I really install a liner and save a bundle in a weekend?
- What measurements and tools will I need to get started on relining my chimney?
- What is the difference between a pre-fab fireplace and a masonry fireplace?
- I have rust stains on the top and running down the siding of my chase. What causes this and what can be done about it?
- Why do I need a chimney cap?
- What are stove pipes, insulated double-wall and triple-wall chimney pipes?
- Can I vent two appliances into one flue?
- How can your Custom Shop help me?
Even small actions can get you on the right path to becoming a green household. By installing one of our stainless steel liners that is optimally sized for the space and purpose, you can reline a damaged flue or correct an existing chimney size to more efficiently handle the exhaust of your furnace, boiler, hot water heater or fireplace. Adding insulation to the liner takes it one step further, and by doing so you not only increase the effectiveness of your appliance, but also help reduce the pollutants entering the air by burning more efficiently. Rockford Chimney Supply offers a lifetime warranty on all our liners, and they are designed for the do-it-yourself homeowner to install and save a bundle.
If you want the ultimate in high-efficiency home heating, you might consider a new fireplace insert or a wood or pellet stove to take advantage of zone heating and reduce your overall energy costs. With zone heating, you dial down the whole-house thermostat while warming just the room or rooms you use the most with an alternate heat source. Rockford Chimney Supply offers top-of-the-line Napoleon stoves, inserts or fireplaces to supplement your heating, lower your expenses and go green. Napoleon has perfected wood-burning technology, and their appliances exceed EPA standards, boast the cleanest burn and lowest emissions, and use renewable and biodegradable fuel.
Many people don't realize that wood is a green source of heat because it comes from a sustainable source, unlike non-renewable fossil fuels. Whether starting with a small step or making a big change, going green isn't an all-or-nothing option--any step you take in a green direction is a smart one. Rockford Chimney Supply offers a huge variety of chimney liner kits, chimney components and heating appliances to help improve energy efficiency and enable greener living.
Last year, did you try using your fireplace for supplementary heat, and found it to be colder than when you started? Did you find yourselves huddled up directly in front of the fire in order to stay warm?
A wood-burning fireplace is beneficial mostly for aesthetic purposes. It looks and sounds great, and can make any room appear cozy and comforting. But the heat a fire gives is radiant heat, meaning it heats objects within its range only. The front of you gets warm from the fire, but the air blowing past you to get to the fireplace can make your back very cold.
A combustion air pipe stuck in the wall beside the fireplace to pull air in specifically for the fire keeps the fireplace from using internal house air. Without this pipe, the draft from a typical fire will pull air into the house from any and every air leak, making the whole house colder and making your home less efficient. It can actually increase the amount of heat you need to supply to the rest of the house. That's because the chimney, while the fireplace is burning, and any time the flue damper is not firmly closed, sucks air up. A standard fireplace is not a cost effective way to heat your house.
Your best bet to turn this fireplace into an efficient heat source is either to get an insert for it, or convert to a woodstove. An insert or a woodstove could heat your whole house for an evening and into the night on the same amount of wood you burn in a fireplace for a few hours, which results in lower monthly heating bills. (Make sure the flue is sized correctly to the appliance so it will draft well and you benefit from higher efficiencies. Flues that are too large cause excessive condensation and / or creosote buildup which damages flue walls and mortar joints. Make sure that a stainless steel liner is installed — older houses may not have flue liners, which are required by code. Chimney liners provide you with a new chimney with no gaps between the clay tiles, bricks, or block sections of your chimney.)
Virtually any type of seasoned wood can be used in a wood stove or insert, so fuel sources are abundant and inexpensive. The newer units use catalytic burners or non-catalytic high tech design which ensures complete combustion and reduces creosote accumulation. The fire itself is confined to the enclosed chamber area, which makes the wood stove safe to use. These units are also much easier to manage and to clean than an open-hearth fireplace, and provide an alternate or emergency heating supply if the electricity or other energy sources should go out for any reason, especially during blizzards, freezing winter rains, or hail storms.
Chimney odors and fireplace smells may be attributed to a multitude of different things. Fireplace smells come from creosote deposits in your chimney, a natural byproduct of burning wood. Chimney odors are usually stronger in the summer when the humidity is high, on rainy days, and / or when the air conditioner is running. As air moves down through your chimney, it brings the inner fireplace smells and chimney odors along with it. Tight sealing, top mounted dampers may help reduce or minimize the airflow (fireplace smells) coming down your chimney.
The real question isn't why does your fireplace smell smoky: the question is why is the odor entering your house? The biggest air pathway to the outside in most houses is the fireplace chimney. A fireplace chimney can allow airflow in both directions. When in use, a fireplace chimney is a powerful evacuating force: the chimney updraft created by an open fireplace fire can move hundreds of cubic feet of air per minute out of the house, in many cases more air than the other pathways combined can supply! This is why you don't smell the smoky odor when a fire is burning in the fireplace: it is only when the fire dies down, and the updraft diminishes to the point where evacuation from other sources overcomes it, that the airflow in the fireplace flue reverses and the odor returns.
What can you do to stop your house from using the fireplace chimney for makeup air? All you need to do is create enough resistance to the flow of air down the chimney so that the other air pathways will provide less resistance to nature's tendency to equalize air pressure inside and outside the house. Here are some solutions:
- Close the fireplace damper when not in use. This will sometimes do the trick, although a damper alone may not provide sufficient flow resistance, as most fireplace dampers are pretty leaky.
- Consider installing a Top Sealing Damper at the top of your chimney. This will provide a weatherproof barrier when you're not burning a fire. The top sealing damper is opened and closed via a stainless steel cable running down the inside of the flue.
- Provide a source of outside air to your combustion appliances, so your gas furnace, oil furnace, woodstove and water heater aren't siphoning air out of the house: the demand for replacement air will be reduced.
- If you are shutting down the chimney for the season, Rockford has a very inexpensive solution called a Chimney Balloon that will keep nasty chimney smells from entering you home.
- Add a good, tight-fitting glass fire screen. This will quite often solve the problem, and will also inhibit the flow of heated air out of the chimney when there's a fire going
The main culprit in chimney breakdown is the acidic moisture that comes from condensed flue gases. This acidic moisture attacks the chimney from the inside. That is why a chimney may look good from the outside, but the inside can be a totally different story. Years of normal use with hot and cold cycles and seasonal weather conditions all can damage your chimney.
Twice the amount of water vapor is created for every cubic foot of gas burned, and when gas temperatures drop below 120 degrees in your flue, that's when condensation begins. When the water vapor condenses, all that moisture stays inside your chimney. Countless drops of acidic rain soak the flue tiles. High efficiency furnaces extract more heat from a given amount of fuel than conventional furnaces and less heat is lost up the chimney. Since less heat is sent up the chimney, the temperature in the flue is often below 120 degrees, so more condensation occurs. The acidic “rain” happens frequently, and the flue seldom has a chance to dry out. This is the side effect of having a high-efficiency furnace; excessive acidic moisture in the flue. This acidic moisture deteriorates the terra-cotta flues and masonry.
Another source of chimney deterioration is chimney fires. While chimney fires can be intense, sometimes a slowly burning chimney fire will go unnoticed by the homeowner while the heat does its damage.
Damaged and cracked flues can turn into a disaster. Toxic carbon monoxide can leak unnoticed through cracks in the flue and into your home. Even small amounts can make you and your family sick.
Burning wood at low temperatures causes incomplete combustion of the oils in the wood, which are off-gassed as volatiles in the smoke. As the smoke rises through the chimney flue it cools, causing water, soot, and volatile compounds to condense on the interior surfaces. The resulting residue that sticks to the inner walls of the chimney is referred to as “creosote”. Creosote is black or brown in appearance. It can be crusty and flaky…tar-like, drippy and sticky…or shiny and hardened. Often, all forms will occur in one chimney system. Whatever form it takes, creosote is highly combustible. If it builds up in sufficient quantities and ignites inside the chimney flue, the result will be a chimney fire.
The possibility of a chimney fire turning into a house fire is another serious risk. There are two ways that a chimney fire can ignite your home. A small crack in the flue can open up, allowing fire sparks to enter the cracks and set the house on fire. Or chimney fires can produce extreme temperatures hot enough to create a flash point that can start fires just from the heat alone. In order to properly maintain chimneys and heaters that burn wood or carbon based fuels, the creosote buildup must be removed.
We highly recommend using a quality nylon / plastic bristle poly brush to clean all types of stainless chimney liners. For your convenience, here is a link to the chimney brushes we offer.
The most popular, effective and economical way to reline your chimney is with a UL listed stainless steel liner. Most masonry chimneys are made with clay tiles that line the inside of the chimney. Over time these tiles can break down or crack. When this happens, the chimney is no longer safe and needs a new liner. A chimney liner kit is a stainless steel pipe inserted inside the existing chimney with various components and connectors. Once it is properly installed, it takes the place of the existing flue. All gases and smoke are now directed through the new liner and cannot penetrate into the home.
There are different types of chimney liner kits, including rigid and flexible flue liner kits. Depending on the design of your chimney, Rockford Chimney Supply can help determine which type of chimney liner you will need. A flexible chimney liner is the most versatile and most likely the best choice. However, in some cases you may opt for a rigid chimney liner. When properly sized and installed, a stainless steel lining system will provide better draft, resulting in less creosote buildup than a comparable clay tile flue system. The kits will include the stainless steel liner, a rain cap, top plate and an appliance connector.
Replacing your existing liner with a new stainless steel chimney liner is not only a wise choice, but offers you and your home all of these benefits:
Safety – Chimney flue tiles are often damaged from corrosive gases eroding the masonry and mortar, chimney fires cracking the clay tiles, or even a shifting foundation. This will leave gaps, allowing toxic carbon monoxide and possibly chimney fire sparks to escape through the cracks into the home, igniting fires. If you have an unlined chimney or a clay tile liner that is many decades old, it is likely that you have cracked tiles or missing mortar that could be letting noxious gases and smoke into your attic or living areas. A stainless steel chimney liner can prevent your flue from allowing heat and sparks to reach the combustible materials inside your home. It can also reduce smoky and smelly down-drafts.
Increased performance of your appliance through improved draft – A stainless steel chimney liner is required for increased performance when you are installing a new heating unit (stove or furnace) that will be vented into your masonry chimney. It also improves chimney draft since hotter gases will draw better than colder gases. Good draft improves fuel efficiency through more complete combustion.
Reduced creosote – Excessive creosote buildup may be an indication that you have an incorrect flue size. An insulated liner also allows less creosote condensation inside the flue by keeping the combustion gases hotter all the way out of the chimney. Creosote fires are estimated to result in almost 15,000 home fires a year.
Affordable – A stainless steel chimney liner can make your home safer for a relatively small investment. These liners are an affordable alternative to most traditional chimney liners. They are less costly than repairing or rebuilding your existing clay flue tiles. They are easier to install than clay tile liners, and the initial installation of stainless steel liners is less expensive. Also, you will have an easier time cleaning this type of liner thanks to the round shape. No square corners to catch deposits of creosote, which makes for a faster, more effective cleaning.
Lifetime Warranty – Because stainless steel is corrosion resistant, you can expect this liner to last a lifetime virtually problem free. And the complete seal applied to the liner keeps nasty emissions away from your masonry, allowing it to last longer and cutting down on required repairs.
Most rigid chimney liner sections are made from 304 or 316 stainless steel alloys. The 316 is more resistant to corrosion and runs a little higher in price. Rigid pipe comes in sections ranging from 6 inch to 4 foot sections and is usually round in shape. The most common wall thickness is 24-gauge or 22-gauge stainless steel.
The seam running down the length of each liner section has factory smooth laser welded seams. Individual liner sections are joined together with the male end facing down. Stainless steel pop rivets and / or stainless steel screws secure the joints. Pop rivets are recommended since screws may work themselves loose from the expansion and contraction of the liner. A storm collar over the support clamp at the top plate, above the chimney, prevents moisture from entering the chimney along the outside of the liner.
A smooth wall rigid liner offers the most efficient venting due to decreased turbulence, and is simple to clean. You can shape it to take full advantage of every cubic inch and offer maximum draft. It can be shaped into rectangular, square or oval. The rigid liner can become heavy when trying to install, and while attaching additional sections. Rigid liner can only be used when there are no bends or offsets in the system.
Flexible liners, unlike the rigid pipe, are one-piece liners. Flexible liners should be used if your chimney is less than perfectly straight with jogs or offsets, and are flexible enough to form to the shape of the flue. The flexible 316Ti is a stainless steel alloy with a small amount of titanium added. Its make-up allows it to resist acids and the stresses of hot and cold cycles. It can be used with solid fuels (wood, coal and pellet), gas and oil. It can withstand temperatures up to 2100 degrees. Flexible liner can also be shaped into rectangular, square or oval cross section.
Flexible liners are available in three thicknesses ranging from .005 for better flexibility, .006 (the long time standard) and the new .013 Double Wall Smooth Wall liner. The smooth wall interior cuts down on creosote buildup which can cause devastating chimney fires and untold loss. It also increases chimney draft by 20% and makes cleaning a breeze.
Even though flexible liners have a corrugated surface, they tend to collect less creosote when used to vent wood fireplaces and stoves, because they flex as they expand and contract with temperature fluctuations, causing buildups to loosen and fall away. The ease of installing flexible liner far outweighs any difference between the rigid and flexible liners.
It is strongly recommended that you do insulate when installing your chimney liner, with either a blanket wrap kit or a pour down insulation mixture of vermiculite and water for liners with little clearance. When you install your liner with the proper insulation, your reline job achieves the UL listing of 1777 Standard, which your insurance company will appreciate.
Our insulation kits include all the necessary components to help your reline job pay for itself in efficiency and minimized creosote buildup and stay cleaner longer. A properly insulated chimney will provide warmer flue temperatures. This ability to maintain warm flue gas temperatures will also have a positive effect on draft. The warmer the chimney, the warmer the gas; the warmer the air (gas), the faster it rises, thus creating a much improved draft and maximizing the efficiency of the appliance. By utilizing the increased draft, there is less likelihood of having a back draft or a smelly chimney odor.
Customers are continually shocked at the cost of relining a chimney. Chimney liner cost can be surprising. There are a variety of factors that play into how much a chimney reline with installation costs, including your area of the country, but on average the cost to have your chimney professionally relined runs anywhere from $2,500 to $5,000. Let's explore the option of purchasing a chimney liner kit and installing it yourself. That's right: if you follow our step-by-step installation, any "do-it-yourself-er" can handle it.
The first thing you should know about our liners is that they have a Lifetime Warranty, which means exactly that — it does not expire. This warranty is the best in the business because it is transferable to the next homeowner, whether it is installed by a professional or yourself.
You can choose to use either a rigid or flexible stainless steel liner kit. Basically there are four components to a flexible liner kit (the liner, a top plate, a rain cap and the connector to attach everything to the stove or insert) and three connections (two right on top of the chimney and one at the stove/insert). Take a look at our chimney liner installation instructions to see how to start and finish your relining project.
Our website, RockfordChimneySupply.com has several DIY videos. Take a look at our easy-to-follow installation instructions and I'm sure you will agree you are the right person for this. If you are not sure what you need to do the job, call us toll free at 1-866-708-2446 and we can assist you with your chimney repairs and insure you that you are getting the items required to complete the relining project. Don't just take our word for it; we encourage you to visit our testimonials page to see what others have said.
You will need to know:
- The inside dimension of the flue you want to line
- The length of the run from 8" above the chimney to either the top of the appliance you are connecting to, or, if you are exiting the chimney horizontally, the thimble or hole in the wall that you want to go through
- The outside measurement of the clay tile or masonry chimney to get the proper fitting top plate
- The exhaust measurement of the appliance you are hooking up to (this is what dictates the diameter of the liner in most cases)
Keep in mind that all flexible liners measure 1/4" larger on the outside. For example, the outside diameter of a 6" liner is 6.25".
Relining a chimney doesn't require many tools. All you will need are gloves, screwdriver, silicone sealant, tape measure and hack saw, and maybe a crimping tool. A pulling cone might also be needed to attach to the liner to help guide it through the chimney; this is available from Rockford Chimney Supply.
The quickest way to tell is by the chimney outside. A chase (for a pre-fab fireplace) is wood-constructed and has a decorative surrounding typically covered with vinyl, aluminum or wood siding, or sometimes simulated stone.
Pre-fab fireplaces are installed on site from UL listed components made in a factory. A pre-fab chimney has a multi-wall insulated metal flue to vent smoke out of house, with a metal cap to prevent water and debris intrusion. A pre-fab fireplace can be removed if damaged and replaced with a new unit for less cost than masonry.
A masonry / brick fireplace and chimney is constructed on site by brick masons using brick and terra cotta tile for the liner, and is more expensive to build and maintain. Many masonry chimneys do not have chimney caps installed, allowing water and animals to get inside the structure and sometimes inside your house.
Pre-fab fireplaces are not any more or less safe than masonry fireplaces.
I have rust stains on the top and running down the siding of my chase. What causes this and what can be done about it?
Pre-fab fireplaces have a metal covering (chase top) to prevent water from entering the interior of the chimney structure. The original chase top is usually made of a cheap galvanized sheet metal, some 1-piece and some several pieces (never acceptable). When you get leaves and/or pine needles blowing around some are bound to get stuck on the water that has collected during rain, snow, and ice storms. Most tops have a low spot that holds water as well. Pine needles and many types of leaves are very acidic when they are decomposing, especially when sitting in water.
The acids break down the galvanized coating and you soon get bare metal. After a while the metal starts to rust, and when water runs off the top during a rain, it carries the rust with it down the side of your beautiful siding, causing a stain that gets bigger over time. You may even hear water dripping on the inside of the chase after a rain if the rust has penetrated the metal, allowing water to seep through. Then you know you have a problem. The rust stains on the outside of a chimney are the first clue, as it can take several months for the metal to pit enough for water to get in. The time to act is when you first notice rust stains, not when you hear water dripping.
The way to fix the problem is to replace the old rusted chase top with a new stainless steel chase cover. Our 304 stainless steel 24 gauge chase cover includes creases on the top to prevent standing water and increase strength, choice of collar height and side skirts, and drip edges that flick the water away from the chase siding. We use and recommend stainless steel for its strength and ability to resist rust. Galvanized metal is not long lasting, and the cost difference is minimal compared to stainless steel. Also, our stainless steel chase cover has a lifetime warranty against rust, corrosion and manufacturer's defects. The galvanized cap only comes with a 12 month warranty.
Chimney caps are crucial to the safe functioning of your fireplace or heating appliance. A properly installed chimney cap will keep sparks and embers from flying out of your chimney which could ignite or start a fire. A chimney cap will also keep rain, snow, sleet, etc. from entering your chimney. Water that mixes with chimney residue can create acid slurry that will weaken the interior of your chimney. Also, chimney caps keep out birds, animals, and debris such as leaves and twigs which could cause blockage in the flue. Last but not least, they help in eliminating downdrafts caused by wind.
RockfordChimneySupply.com is your source for the highest quality chimney caps. We have a complete line of stainless or copper chimney caps, chase covers, top dampers and single- or multi-flue caps to fit any chimney or vent outlet. For added value, all flue cap or fireplace chimney cap orders ship free! If you need help choosing or sizing the optimal chimney cap for your needs, contact our customer service technicians who will be happy to assist you.
Single-wall stovepipes can be installed from a stove to within 18" of any combustible material. Double-wall stovepipe has the same application but with clearances down to 6" from wall combustibles and 8" from ceiling combustibles. Neither single nor double-wall stovepipe can be used to penetrate ceilings, walls or roofs.
In a vertical chimney pipe installation, stovepipe runs from the stove to a ceiling box designed for a flat or cathedral ceiling. Insulated pipe goes through the box, through an attic or second floor if applicable, through the roof and up to a rain cap. In a horizontal installation, a wall box is used and the insulated vent pipe goes through the wall and up the exterior of the building to a rain cap.
The function of the insulated double- and triple-wall chimney pipe is to protect adjacent building structures from the high temperatures created by high-output appliances. To do this requires that the pipe remain cool on the outside by having an internal design that creates a fire-safe venting system. Manufacturers use different techniques to achieve this. Chimney pipe may be air cooled, have insulation packed in the gap(s) between the pipes, or have a ceramic insulating blanket in conjunction with the gap(s). The goal is to minimize the outside diameter of the pipe and the allowable distance from combustibles. This can be 2" for double-wall pipe and 1.5" for triple-wall pipe. The outer wall of chimney pipe is stainless steel or galvanized steel. The inner wall is stainless steel. In three-wall pipe the intermediate wall is aluminized steel.
Double-wall insulated pipe is listed as Class A vent pipe and must meet certain UL standards. Double-wall requires pipe capable of safely operating with an internal temperature up to 1,200 degrees Fahrenheit and withstanding a maximum temperature of 1,700 degrees Fahrenheit. Triple-wall insulated pipe has the same application as the insulated double-wall, but with different temperatures and clearances. Triple-wall requires pipe capable of safely operating with an internal temperature up to 1,700 degrees Fahrenheit and withstanding a maximum temperature of 2,100 degrees Fahrenheit
Venting two appliances into the same flue saves a homeowner from investing money in a second chimney and can speed up the installation of appliances, but there are restrictions.
A wood-burning stove or fireplace is always required to have its own, unshared flue. This is largely because there is no practical way to connect another wood, gas or oil appliance to that flue without causing air infiltration into the flue. Air infiltration slows the rate of exhaust travel up the flue while simultaneously cooling the wood exhaust gases, causing excessive creosote condensation and an increased incidence of chimney fires. The codebook is quite clear on this point: every wood-burning appliance must have its own flue. The only way you can safely vent an oil-burner and a wood-burner into the same chimney is if you install two stainless steel chimney liners, one for each appliance.
When dealing with oil exhaust intrusion into a chimney venting wood exhaust, other factors come into play. The acids contained in oil exhaust blend with a colorless, volatile liquid compound found in wood exhaust to create an extremely corrosive mixture inside the flue. This mixture attacks both the bonding agent in the mortar and the actual chimney structure itself, drastically reducing the usable lifetime of the chimney.
Finally, the combination of oil soot and wood creosote in the flue presents the most dangerous of chimney fire hazards. Oil soot ignites at extremely low temperatures, and wood creosote burns at extremely high temperatures. When ignited, this mixture "spits" burning balls of oily creosote out the top of the chimney in every direction. Thus, a chimney flue that is coated with a combination of oil exhaust and wood exhaust deposits is much more likely to experience repeated chimney fires, and those fires are much more likely to destroy the chimney and / or burn down the neighborhood.
Review local building and fire codes to determine any local limitations on gas and oil burning appliances together into the same flue. Replace the chimney liner with a liner large enough to meet the venting requirements of the two appliances if the current liner is not adequate. Attach a wye (pronounced "y") connector to the chimney liner, or a double snouted tee with two take offs, which is designed to allow you to connect two appliances to one chimney liner. Some codes require that the appliance with the lowest BTU input should be attached in a position higher than the appliance with the greatest BTU input.
We know that as DIY homeowners, you need specific products made in a timely manner and at reasonable prices. In our Custom Shop we have filled hundreds of these product orders made from stainless steel and copper, including chase covers and multi-flue caps. Because we have these capabilities, you can benefit from Rockford's ability to deliver custom chimney liner components as well as typical standard parts required to get the job done right the first time every time.
We pride ourselves in delivering quality custom parts and shipping them with a quick turnaround. Here at Rockford we constantly get compliments for offering this service to our customers. Remember, if you can dream it, we can deliver it.