null Chimney Pipe and Stove Pipe FAQs - Northline Express


Chimney Pipe and Stove Pipe FAQs

Mar 1st 2012

Class A Chimney Pipe

NLE iconI want to install my own chimney pipe but don't know where to start.

The easiest way to start is to go to our Chimney Pipe Installation Planning Guide. We'll answer several questions here though.

  • Start first by determining what type of chimney your appliance requires. This information is in the instruction manual of your appliance and there are several types of chimney. For instance; Class A chimney is for wood, coal, and most fuels however, it may not be required for your gas appliance or pellet appliance. Pellet vent is for pellet burning appliances or corn burners. B-Vent is for certain gas appliances but not all. Direct-vent chimney is for a direct-vent gas appliance. Bottom Line - Read your instruction manual to see what type of chimney is required for your appliance.
  • Next,determine the size of the chimney pipe needed. Never go smaller than what is required or you risk having smoke or gasses backing up or a poor draft in other words.
  • There are different requirements for the US or Canada in some cases which we point out based on the type of chimney.
  • Once you determine the above 4 requirements you will need to choose a manufacturer and brand of chimney (many manufacturers offer several brands within a type) . Although several brands are available, we recommend Dura-Vent DuraTech for most new installations due to their reputation, warranty, product offering, availability, and price. Visit our Class-A Chimney Pipe section for further recommendations.

  • Also see our article on Proper Venting.

NLE iconShould I install my chimney vertically or horizontally through the wall and then up?

A: A Thru-The Wall installation is more likely to have drafting issues because of running cooler and because of elbows etc. Also, they are more challenging to clean and more expensive to install. Always run straight up if you can.

NLE iconWhich manufacturer or type should I go with?

We recommend Dura-Vent chimney pipe for new installations. Their reputation, warranty, product offering, availability, and price are hard to beat. Also see our article Which Chimney Pipe is Best For Me?

NLE iconWithin the Dura-Vent product line, which brand should I choose?

A: The most popular Class A Chimney Pipe we sell by far is the DuraTech brand by Dura-Vent. DuraTech is a double-wall chimney system which has a larger selection of components than most others, it is priced well, preferred by professional installers, and is widely available.

NLE iconWhat if I get stuck and can't figure it all out after I buy the chimney? Can I return it?

If you get stuck please give us a call. We have several trained customer service representatives that are eager to help you. If you decide to return all or part of your purchase…no problem. Our philosophy is to help people get what they want or need or to take it back if it isn't working out. There are no re-stocking fees but you'll be responsible for shipping costs. We're here to help you succeed in your chimney pipe installation.

NLE iconHow do I figure out my roof pitch so I know what chimney pipe flashing to buy?

See our article How Do I Measure Roof Pitch.

NLE iconI have seen people use black pipe for the entire wood stove chimney installation. I'd like to save money but is this safe?

Absolutely not! Black pipe is not chimney pipe and should only be used up to the point of penetrating the ceiling or wall. From that point on class A chimney pipe is required. Black single wall stove pipe has a clearance to combustibles of 18” (double-wall black pipe has a clearance of 6") whereas class A chimney pipe is generally 2”. Black pipe used outside will run way cooler flue temperatures than class A chimney and will potentially build up creosote quite rapidly increasing the chance of a chimney fire. There a no safe way to use black stove pipe for the entire chimney system so ask yourself…Is saving some money worth me or my family's life and home worth the risk?

NLE iconI have a round metal class A chimney in my home already but the diameter is 6" and the wood stove I am installing has an 8" flue. Can I use a reducer and use my 6" chimney?

Typically you should never reduce the size of the chimney smaller than the outlet of the wood stove flue since doing so will usually cause smoking out the front or less than desirable draft up the chimney. However, with that said and assuming the chimney you have is in good condition, why not give it a try? I have seen installations with a chimney smaller than required that have a very strong draft that work just fine. Just buy a reducer and try it, if it smokes badly then you'll need to replace the chimney with the proper size.

NLE iconI have a chimney that is the proper size but my woodstove/fireplace smokes badly out the front. What can I do?

There are several things you need to check;

  • Have you cleaned your chimney or had it checked for obstructions like a birds nest, excessive creosote build-up, etc? If not then get a powerful flashlight, pop the chimney cap off and take a look (or look up from the bottom of a fireplace). Clean your chimney if necessary. We carry a huge selection of chimney cleaning products in our Chimney Brush category, our Chimney Cleaning Accessories category, and our Chimney Maintenance category.
  • If your wood stove or fireplace smokes out the front only at first but drafts fine after a fire is started then most likely the cause is due to a cold chimney that has what is called a downdraft where the outside air is coming down the chimney into the home. This is more common on an exterior chimney like many fireplace chimneys. There isn't an easy cure for this situation but one solution would be to roll up a newspaper, light it, and hold it up inside the chimney to get the draft reversed then light your fire. Another option is to install a draft inducer in the chimney or on top of the chimney. A draft inducer is a fan that either pushes up the smoke or pulls it up and out. Draft inducers work very well and generally solve the problem but are somewhat expensive. Draft inducers are available in our Chimney Draft Inducers category.
  • If your wood stove or fireplace only smokes when the wind is blowing from a certain direction you can try a special cap called a Vac-U-Stack or a draft inducer which will generally solve the problem. For a smoking masonry fireplace a common problem is the chimney flue either too small in relation to the opening or the chimney is not high enough. A quick and easy test is to take a piece of aluminum foil, pull out enough to span the width of your fireplace, fold it to a 4” high x however wide your fireplace is, and tape it up to the opening of your fireplace. In effect you have reduced the size of your fireplace opening. If this simple test works then go to our Smoke Guards category and buy a Smoke Guard for a permanent installation.
  • In other cases your chimney just isn't high enough. An easy and inexpensive way to test if that's the case is to buy some inexpensive black pipe (for round chimneys) or get some furnace duct work made to size (for masonry chimney flues) and temporarily add this section to the top of your chimney. If the poor draft is cured using this method then either buy enough class A chimney pipe to extend the height (round chimneys) or for a masonry chimney contact a mason to extend it or buy a Flue Stretcher.

NLE iconI need more class A chimney pipe brand XYZ. Can I use any other brand of chimney pipe instead?

No. Every manufacturer of class A chimney pipe uses their own methods to secure the pipe together so one brand most likely will not connect together correctly with another brand of pipe and could be dangerous due to a poor fit as it could come apart or leak creosote, smoke, or gasses.

NLE iconCan I just run single wall black pipe all the way up?

No, you must transition to Class A chimney pipe at the ceiling or wall.

NLE iconCan I run the Class A chimney pipe all the way to the stove?

You could but why would you want to? Black stove pipe radiates extra heat into the room and is considerably less expensive than class A chimney pipe.

NLE iconI have a free standing wood stove and need pipe, what do I need?

Go to our Chimney pipe Installation Planning Guide for additional information and help.

NLE iconCan I mix MetalBest chimney pipe with DuraTech or DuraPlus chimney pipe?

No, you can't intermingle different pipe manufactures. They have their own locking mechanisms and are brand specific.

NLE iconDo you have a special adapter to use DuraTech with MetalBest?

No, you can't intermingle different pipe manufactures. They have their own locking mechanisms and are brand specific.

NLE iconQ: I have a 7" outlet on my stove. Should I run 7" or up it to 8"?

7" pipe will work fine but if you ever decide to put in an 8" appliance you would need to upgrade the pipe to 8". Same situation would apply if you were using a 6" appliance. Years ago most wood stoves were using an 8" flue but over the last several years the manufacturers have made smaller more efficient wood stoves and most stoves these days use a 6" flue. 6" and 8" chimney pipe are easier to find than 7" and many times you'll find more options in the 6" and 8" sizes.

NLE iconWhat's the difference between DuraTech and DuraPlus chimney pipe?

DuraPlus is a triple-wall chimney system with a layer of insulation between the innermost wall and the middle wall whereas DuraTech is a double-wall chimney system with a layer if insulation between the two metal walls. Both DuraTech and DuraPlus are tested to the same temperature, 2100 degrees and clearance to combustibles on both brands is 2”. DuraTech is the most popular choice in most cases and is our top selling brand of pipe. DuraTech has a wider selection of pipe lengths and finishes, has a wider selection of fittings and components, is the most popular choice among professional installers, and is widely carried across the USA. DuraPlus is the only choice for mobile home installations and DuraPlus HTC is the only choice for Canadian wood stove installations.

NLE iconCan I mix DuraTech with DuraPlus, or DuraBlack with DVL, or DuraTech with Selkirk, etc?

NO, NO, NO! They will not fit well together or at all and will pose a safety issue. Stick with one brand of chimney pipe and one brand of stove pipe.

NLE iconWhat is the difference between stove pipe and chimney pipe?

Many confuse the terms. Stove pipe is usually painted black and is used in the interior on the home until you transition through a wall or ceiling then class A chimney pipe is used thereon. Stove pipe, black pipe, single wall pipe all refer to the same thing. Chimney pipe, class A pipe, triple-wall pipe, insulated pipe all refer to class A chimney pipe. Double-wall pipe could be associated with either double-wall black pipe like DVL or double-wall chimney pipe like DuraTech.

NLE iconWhat is the offset and rise for both black pipe and chimney pipe.

We have this information available in the installation instructions for each brand of pipe. Additionally you can find the DuraVent Pipe Offsets here.

NLE iconHow high do I need to run my class A chimney pipe?

The National Fire Protection Association Standard #211 states: “Chimneys shall extend at least three feet above the highest point where it passes through the roof of a building, and at least two feet higher than any portion of a building within ten feet.”

NLE iconWhy should I buy from

We're experts when it comes to chimney installation and we have a full staff eager to help you solve your chimney system challenges. We have a large stock of chimney products from pipe to brushes to cleaners and everything imaginable for your fireplace, wood stove and pellet stove. Unlike many internet retailers who carry little or no inventory, we have a 23,000 sq. ft. warehouse stocked with product. The big advantage there is we can generally process your order faster, provide better tracking information about your order and we understand the products since we see, feel, and handle them. NorthlineExpress has an A rating with the BBB and we have a policy to keep the customer happy even if we lose money, it just makes life easier. When you call our company you'll talk to an individual who is always looking out for your best interest. Also see Why Buy From and our Welcome pages.

NLE iconCan I use DuraTech chimney in Canada?

For wood stoves and most fireplaces being installed in Canada DuraPlus HTC is the only choice from Dura-Vent. The reason is that the HTC pipe has 2" thick insulation to pass the 2 hours burn/temp test required in Canada. The DuraTech has a 1" blanket of insulation and will not pass the Canadian test but passes the USA test. DuraTech's only listing for use with a wood burning appliance in Canada are a few Zero Clearance fireplaces listed for use in Canada. Other than that, DuraTech is only listed for oil and gas in Canada. Always read your appliance instruction manual for proper chimney recommendations. DuraPlus HTC is listed for Canada use to ULC S629 (143-P-03-2).

NLE iconHow do I maintain my fireplace, wood stove, or pellet stove chimney?

It isn't difficult but there are various types of chimneys from masonry fireplaces, pre-fabricated chimney pipe, pellet vent pipe and more. We answer all those questions in the following articles;

Black Stove Pipe

NLE iconShould I buy single wall or double wall stove pipe?

It depends on your clearance to combustibles. Single wall black stove pipe needs to be at least 18" from combustibles, will radiate more heat than double wall black stove pipe (desirable in most cases), costs way less, and can be cut to length if needed. Double wall black stove pipe has a 6" from combustibles and isn't very hot to the touch. Clearances to combustibles can also be reduced with various items such as Pipe Heat Shields. Mobile home installations require double wall black stove pipe for added safety.

NLE iconCan I go through my wall with single wall or double wall black stove pipe?

No, you must use factory built class A chimney pipe such as DuraTech or DuraPlus once you transition through a wall or ceiling.

NLE iconWhat is the biggest difference between brands of single-wall black stove pipe?

Black stove pipe is available from NorthlineExpress in 3 brands of single wall and at least two brands of double wall pipe. Single wall black stove pipe is offered in three grades; Snap-Lock, DuraBlack, and HeatFab. Snap-Lock pipe is the least expensive but not necessarily the best choice. It snaps together hence its name, has thinner gauge metal than DuraBlack and doesn't fit together as nicely as other brands of black stove pipe. DuraBlack is our most popular choice of black stove pipe as it is less expensive than HeatFab, is 24 gauge thick, fits together nicely with Dura-Vent chimney systems, and has a lot of fittings available. HeatFab is the thickest black pipe at 22 gauge, has many fittings, fits well together and is a good choice for those looking for the highest quality and longest lasting stove pipe.

NLE iconShould I screw the sections of single-wall black pipe together?

Yes. Screwing sections of black stove pipe together adds an extra margin of safety and is generally required by most building codes. Double wall black stove pipe like DVL can be screwed together but don't penetrate the inner wall. We sell specialBlack Stove Pipe Screws for that purpose.

NLE iconDoes the crimped end of my black stove pipe go up or down?

The crimped end of the stove pipe goes down. Many people think the crimped end goes up to keep the smoke in the pipe but that is incorrect. First of all the smoke is not just going up on its own, it is being drawn up the chimney by the natural draft. Secondly the crimped end must go down so that if condensation or creosote runs down the stove pipe it will remain inside the pipe or wood stove/fireplace.

NLE iconQ: I have an oval opening on my wood stove. Do you sell oval to round adapters?

Yes, we do. However they are sometimes very hard to match up. You may need to find a sheet metal shop and have a custom one made up. Search our Stove Pipe section to see if we have a size available that matches your stove.

Pellet Vent Pipe

NLE iconI want to install my own pellet vent chimney system but don't know where to start.

See our section on How to Install Pellet Vent Pro Chimney Systems and Pellet Vent Pro Installation Instructions.

  • Start first by determining what size of chimney your pellet stove requires, pellet vent pipe is available in 3" and 4" diameters. This information is in the instruction manual of your pellet stove. Never go smaller than what is required or you risk having smoke or gasses backing up or a poor draft in other words.

  • Determine the layout or installation type that is applicable for your home. For pellet vent the most popular installation is thru-the-wall terminating outside versus a straight up installation and is relatively inexpensive.

  • Once you determine the above requirements you will need to choose a manufacturer and brand of chimney (many manufacturers offer several brands within a type).

NLE iconQ: Which manufacturer or brand should I go with?

There are several brands available, we recommend Dura-Vent PelletVent Pro for new installations due to their reputation, warranty, product offering, availability, and price. Our Website displays “customers choice” manufacturers & brands for Pellet Vent Pipe.

NLE iconQ: What is the difference between PelletVent and PelletVent Pro?

Dura-Vent PelletVent is less expensive than PelletVent Pro, however, we recommend Dura-Vent PelletVent Pro. PelletVent Pro is available in galvalume or black (galvalume only in PelletVent), has a wider selection of components available and has a 1” clearance to combustibles versus 3” clearance on PelletVent and many other brands of pellet vent pipe. PelletVent Pro is preferred by professional installers and is our top selling pellet vent pipe. Additional information is available in our Pellet Vent Pipe section.

NLE iconQ: Can I reduce a 4" pellet stove to a 3" pellet vent pipe?

No. If you already have a 3" pellet vent pipe system installed and you now have a 4" pellet vent stove you will need to replace the 3" pipe with 4" pellet vent pipe otherwise the pellet stove will most likely not draft properly. You can always increase a 3" pellet stove for use with a 4" system but you should never reduce the size. Optimum performance usually is achieved when the pellet vent diameter is the same as the appliance. It is possible to have too much draft, however it is generally not an issue. Too little of a draft is a much bigger problem since the stove may not burn properly or gasses can back up in the home. For a 3" to 4" pellet vent increaser use item 5SP-3PVP-X4AD or 5SP-3PVP-X4ADB.

NLE iconQ: Is there a fresh air intake available for my pellet vent stove?

Yes. See item code 5SP-3PVP-AIK for Dura-Vent PelletVent Pro systems and can usually be installed with other pellet vent pipe as well.