What is a Stove Pipe?
A stovepipe moves exhaust fumes and particulates from your wood-burning stove to the exterior of your home. Often called chimney connector or black pipe, stovepipes are single or double-walled metal vent pipes. They bridge the gap between your appliance and the chimney pipe system.
So, when is stovepipe needed? If you have a wood burning stove, you'll soon find that stovepipe is necessary as well. Most stoves do not come with vent pipe unless noted otherwise. You'll almost always need to buy the stovepipe separately.
Things to Consider Before You Buy
Before you purchase a stovepipe, you will need to learn which type of pipe works best for your stove and your home. There are two primary types of stovepipes - single-walled and double-walled. There are different reasons for using one over the other, and we'll go over that in this next section.
In many instances, you'll often see or hear the terms stovepipe and chimney pipe used interchangeably. But, they are different products with different uses and should never be confused as the same product.
Stovepipe is only used inside the room where the stove is located. Stovepipe is designed to be run between the stove and the ceiling or outside wall. From that point, you'll need a class-A chimney pipe system to go through that wall or ceiling.
You'll also find some venting pipes called triple-walled or insulated pipes. These terms are exclusive to chimney pipe and not related to the types of stovepipe available.
When deciding on which variety of stovepipe you need, here's one quick way to figure out the one that's right for you. Answer this question: With your stove installed, how close will your pipe be to a combustible wall? If you've got more than 18 inches of space, a single-wall stovepipe will work for you. But, if your pipe will be closer than 18 inches to combustible material and you don't plan on installing wall protection, you need a double-wall pipe. These only need 6 inches of clearance due to the air space between the stove walls.
Also, if there's a long distance from your stove to your wall or ceiling, a double-wall stovepipe will be the best option. Double-wall stovepipes have grown quite popular with the prevalence of high-efficiency stoves. These modern stoves produce lower flue gas temperatures. This is due to their effective recirculation systems.
Using a single-wall pipe for a long run with a modern stove will result in a lot of lost heat as it radiates through the pipe wall. The loss of radiant heat can lead to increased creosote buildup which is caused by lower flue gas temperatures creating condensation in the pipe. This can even lead to a total loss of stove drafting, causing the stove not to work at all. Double-wall pipes ensure your stove operates correctly and they prevent excessive heat loss.
Top 5 Brands and Manufacturers
Many manufacturers out there offer their own brands of stovepipe. So, how will you know which ones are worthy of your trust? We've got you covered! In this section, we feature some of the best brands in the industry for you.
- Heat-fab — A leading manufacturer of venting systems for more than 20 years, Heat-Fab makes most of their products in North America. Their stoves feature adjustable height constructions. They are made from 22-gauge steel with laser welded seams. All Heat-Fab products are compatible with each other and fit most decor. They also come in a variety of lengths and diameters to fit any installation.
- Imperial — Known for their single-walled, Snap-Lock stovepipe, Imperial transformed the industry. They discovered technology to "snap" the seams of pipes together. Their connection system makes every seal easy to put together without sacrificing reliability. Snap-Lock comes in several diameters to fit your installation. They also have a great supply of reducers, couplers, and other parts to make installation easier.
- Duravent — With over 50 years experience, DuraVent makes some of the most dependable and long-lasting stovepipes out there. They have two kinds - DVL and Dura-Black. DVL is their double-wall stovepipe, and Dura-Black is the single-wall version. The pipes are made from 24-gauge steel with spot-welded seams. These stovepipes come in three lengths, and the black finish goes well with nearly any system. You can also connect any DVL to other DVL products; the same goes for Dura-Black products.
- Selkirk — Selkirk understands the cost of construction and maintenance. They make products that are dependable. With 90 years under their belt, they make stovepipes and produce all the accessories you need. Most of their pipes are double-wall varieties and come in both 6-inch and 8-inch diameters.
- Security — This Canadian company has been making chimney products for more than 50 years. They offer both single or double-wall pipes. They're made from 24-gauge steel and available in 6, 7, and 8-inch diameters. Most of Security's pipes come in black to blend with any home aesthetic.
When searching through brands, you'll find different classifications of pipes. There are snap-lock or snap-seam pipes, rolled-seam pipes, and continuously-welded pipes. Let's go over what all this means.
Snap-Lock or Snap Seam — This kind of stovepipe ships in one flat sheet. The edges of the sheet are rolled together in the shape of a pipe and pushed until the pipe snaps in place. Modern snap-lock pipes work much better than older versions. They prevent all smoke leakage from the seams. This type of pipe is usually only available in painted black steel and is a 26 gauge thickness. For reference, the higher the gauge number, the thinner the metal.
Seamed Pipe — Many consider the rolled-seam pipe a step up from the snap lock. This pipe does not come in a flat sheet; instead, it comes fully assembled and ready to install. The pipe is 22 or 24-gauge steel. Its name hints to the way it's manufactured. The seam is machine-rolled to create a very tight and secure connection.
Some manufacturers also clinch or tack-weld the seam for longevity. This is a significant advantage of the rolled-pipe system. It even has flared ends which makes for a smooth and tight connection that doesn't need sealant. This type of pipe is available in both black painted steel and stainless steel varieties.
Continuously-Welded Pipe — This vent system will give you the longest-lasting pipe but at the highest cost. It's also not very common. It's made from 22 or 24-gauge steel on a pipe that has no visible seam. The pipe is TIG welded. And, it's available in both manufacturer-specific and non-manufacturer-specific varieties. Continuously-welded pipes are most common in a stainless steel finish.
Double-Wall Stovepipe — Like the name suggests, this pipe has two walls - an inner wall and an outer wall. The inner wall of a double-wall pipe is made of 304 or 430-grade stainless steel with either a rolled or welded seam.
Insulating air space fills the gap between it and the outer wall. This type of stovepipe is larger in diameter than the single-wall type for obvious reasons. It has two pipes instead of one. Because of this, the dimensions can be misleading.
For example, single-wall stovepipes with an advertised 6 inch diameter have a true inner or outer diameter of 6 inches. But, a double-wall pipe with a 6-inch inner diameter does not include the dimensions of the outer wall. This means it will likely be 7 inches or more in diameter overall when accounting for the outer wall.
The outer wall consists of 24 or 26-gauge galvanized steel. The inner and outer walls connect with a fixed collar that is pressed and riveted to the ends. This fixed collar has evenly spaced air holes that allows for cooling air to move freely along the entire system length. Double-wall stovepipes do cost more than single-wall pipes, but with the right care, they can last a lifetime.
If you are installing a stovepipe system yourself, you'll need some essential parts to create a proper connection. It depends on the way you plan to vent the exhaust, of course. For a vertical installation, place the stove in a spot where the pipe will maintain the proper clearance to combustibles. If this is not possible, a noncombustible wall shield will be needed to make the installation safe.
Please note that modern designs of vertical stove piping systems assume the chimney is already in position. So, from here on, we'll assume you have an existing chimney.
Now, let's take a look at what components you'll need to make a functional link between the stove and chimney.
Vertical Installation Components
Vertical installations are relatively straightforward compared to horizontal installations. A marginally assembled vertical joint of a stovepipe is not likely to leak. But, this is not the case for horizontal installations.
Horizontal connections must be tight and square to prevent condensation drips. With horizontal installations, there is a greater chance of you placing the stovepipe too close to a combustible surface. To avoid a dangerous situation, be sure to measure for proper clearances carefully.
Appliance Adapter — Also known as a stove adapter, this little connector attaches to the flue collar of the stove. It has a crimped and tapered bottom that holds it in place when inserted to the stove collar. You use these adapters for pipes that are unable to connect to the stove directly due to slight diameter differences.
A good example is rolled and welded-seam stovepipes. These products do not connect directly to the stove. Because of this, you'll need an appliance adapter to compensate for the size variances.
Appliance Adapter Damper Section — It's much like the appliance adapter just mentioned, but it has a damper. A damper helps regulate the flow of the flue gases inside the pipe. This type of adapter is essential for wood stoves built prior to Tier 1 EPA standards, meaning that they use ceramic baffles or a catalytic combustor in place of a damper.
Older wood-burning stoves do not have an internal damper or baffle. Instead, they rely on an external damper to control the stove burn rate.
Piping — Rigid lengths of pipe make up the majority of the venting you will run. We recommend you get the longest length available from the manufacturer. The goal is to avoid having to make so many connections, which is time consuming and leaves more chances for smoke leaks during a downdraft of blockage.
You must secure each connection with self-tapping sheet metal screws. Most manufacturers recommend a total of 3 #12 screws at each connection. This will ensure a secure fit and a rigid pipe system.
Elbows — Elbows are angled piping components that allow you to maneuver the venting system. Some installations will require an elbow to align the pipe with the chimney system. Elbows come in handy if you have an HVAC duct or a framing member that you can't move. They also help if you need to adjust the location of your stove.
Do not use 90-degree elbows in a vertical installation. Instead, use a pair of 45-degree elbows to jog the pipe into position. You may also find that a short length of pipe can be used between the elbows to gain additional offset if needed. While they are convenient, try to avoid using an elbow if possible, as each elbow added restricts flow slightly.
Telescopic Lengths — Telescopic lengths offer an extended piece of piping needed to cover shorter distances. They operate much like the collapsible body of a portable telescope - hence the name. Put plainly, telescopic lengths consist of two pipes, one fitting inside the other.
Both pipes are rigid, but the inner pipe has a slightly smaller diameter than the outer pipe. This allows you to extend the length of a pipe without the need to cut other piping. These operate much like a telescope, extending and collapsing. The extra length helps you connect the pipes to the chimney support or chimney collar.
Telescopic lengths are only available for rolled and welded-seam pipes. Double-walled pipes rely on telescopic lengths to complete the installation. These help make the final connection between the stovepipe and the chimney pipe.
Slip Connector — A slip connector is the most common way to connect a single-wall stovepipe to a chimney system. This short section of pipe fits inside the end of the stovepipe you plan to connect to the chimney. Make sure you position the slip connector before installing the stovepipe itself.
The cylinder-shaped adapter or connector on the pipe "slips" upward and over a seam. Secure it in place to the seam using screws before connecting it to a ceiling support or chimney adapter. You cannot use slip connectors with double-walled stovepipes.
Size Adapters — Some manufacturers offer size adapters that allow you to alter the size of your stovepipe system. A good example of when you would need one of these is if your new stove has a 6-inch flue collar but needs to connect to an 8-inch chimney system. We recommend you use size adapters as a last resort because they can reduce the efficiency of the stove.
Modern stoves function best with chimney systems that match their flue collar diameter. So, if you resize your system you'll need to install an adapter as close to the end of the stovepipe run as possible.
Chimney Adapters — These adapters are only needed for double-wall stovepipe systems. This component makes the final connection between the last section of stovepipe and the chimney support box or collar.
Chimney adapters come with a sizing ring. This piece connects to a beauty ring attached to the chimney support box. This makes the connection more aesthetically appealing.
Horizontal Installation Components
Elbows — You'll recall how 90-degree elbows aren't allowed for vertical installations. Yet, they are essential in horizontal installations. Most stoves feature a top-mounted flue collar. You will need a 90-degree elbow to redirect the vertical run of your stovepipe toward a wall.
Here's another point worth noting. Unless stated by the manufacturer, make sure you clear at least 12 inches of vertical piping from the stove before installing an elbow. This length allows the stove to establish draft before being restricted by the elbow.
Tees — These are specially designed fittings that look like the letter "T." Their shape facilitates the connection to a rear-venting stove or appliance. You can also use tees in place of a 90-degree elbow for installs that have a horizontal flue collar that then directs to a vertical stovepipe run. The base of the tee will feature a removable cover called a clean out. The clean out allows access to the stove pipe for soot removal with a chimney brush system.
Wall and Chimney Thimbles — For those looking to run your horizontal stovepipe through a wall or into a masonry chimney, you'll need a wall or chimney thimble. A chimney thimble is a sleeve and trim collar that passes the stovepipe into a clay chimney thimble, which then connects to a vertical flue within the masonry chimney.
Check with your local code enforcement agency beforehand if you need to pass a stovepipe through a combustible wall. Not all areas allow such a practice. However, if there's a combustible wall built over a masonry chimney, an insulated stovepipe thimble is usually allowed to pass the stovepipe into the masonry chimney.
Helpful Installation Guidelines to Follow
As you install your stovepipe, you'll need to follow some basic rules. While some installations are specific to a brand or a particular kind of run, there are some general guidelines worthy of you remembering.
- Be sure you always use furnace cement when attaching an appliance adapter to the stove. This cement keeps gases from leaking around the flue collar. If the stove allows for it, use screws to secure the adapter.
- Do not cut the stovepipe sections unless the manufacturer guidelines allow it. Sometime ago, it was common to cut stovepipe, but it is not common practice anymore. Welded-seam and rolled-seam systems have slip connectors sections to accommodate odd lengths. If you were to cut the pipe, you would remove the specially designed flared ends and create an unsafe installation. The only stovepipe systems acceptable to cut are snap-lock and snap-seam. Even for these, the cut ends have to be re-crimped for proper fitting.
- Install snap-lock and snap-seam pipes with the male end down. By doing this, you can funnel all the creosote and condensation into the stove to be burned off. Installing either pipe system male end up will cause fluid leaks that will stain the outside of the pipe. Welded and rolled-seam systems should be installed the same way. Some double-wall stovepipe systems follow different configurations. However, most systems have labels with the proper orientation.
- Use self-tapping screws at each junction. It's recommended to use three screws spaced evenly around the perimeter of the joint. You can hide the screws with high-temperature black paint or use stainless steel fasteners with stainless steel pipes.
Maximizing the life of your stovepipe will take some work, as with anything, but we are here to give you some tips.
If possible, burn well-seasoned, mid to high-density wood only. Hot, controlled fires produce less creosote buildup, which means less of it will stick to the inner walls of your pipes.
Check the inside of your stovepipe at least once a month during the burn season. You can do this by collapsing the slip connector or telescopic section of the stovepipe and inspecting it with a flashlight.
If you can, do a top-down inspection from the chimney termination. This check will help you catch any debris that might have built up over time. When doing this, you can clean the system by removing the chimney cap. Make sure you have the right size poly brush. If you have any tee caps, stove catalysts, or baffles, remove them to keep cleanup simple.
Do not burn trash in your wood stove. Junk mail and plastic release dangerous chemicals and can coat your stove pipe with gunk.
Do not burn painted or chemically-treated wood. The fumes they release can be harmful and sometimes even deadly.
Use a chimney-cleaning log, especially if you haven't inspected the inside of your stove pipe. These logs make cleaning the pipe out a little easier.
When in doubt, hire a professional chimney sweep. If you're unsure of your abilities or don't have the time to clean your pipes properly, don't do it. But, the last thing you should do is let your pipes go a season without inspection. Hire a chimney sweep and give yourself peace of mind.