Steel Liners for Masonry Chimneys

Traditionally, chimney have been made out of brick and mortar or cement block and mortar with clay tile flues. These chimneys are referred to as masonry chimneys, and the clay liners are installed when the chimney is being built. While durable, over time (usually over 20-30 years) the clay liners in the masonry chimneys will crack and degrade, and when they do, the chimney is no longer a code-compliant chimney. If the cracks are accessible, they can be repaired, but if not, then the chimney needs to be relined with steel liner. If the tile liner in the masonry chimney is not code compliant, then it must be removed and the steel liner must be insulated. It is possible to purchase a pre-insulated liner or to glue an insulation blanket around the liner and wrap it with a steel mesh. The insulation keeps the heat off of the interior of the chimney in the same manner as a tile liner ensuring better draft and protecting the chimney from the combustible material around it. In the state of Maine, wood stoves and fireplaces inserts must have a minimum cross-sectional diameter of at least 6". Mazzeo's sells steel liners and liner kits from a variety of different manufacturers at very affordable rates. If you need more information regarding how to line your masonry chimney, email:

Class-A Chimney Systems - The First Choice for New Chimneys!

Class-A chimneys are pre-fabricated, stainless steel chimneys and are usually made of insulated, double-wall stainless steel.  If you are considering having a new chimney put into your home, your first choice should be a modern, Class-A chimney rather than a traditional masonry chimney! Here's why:  

  1. In our experience, they burn more cleanly! Since the flue is made of a slick, stainless steel that does not absorb water and trap the cold like clay liners do, Class-A chimneys warm up quickly and draft far better than traditional masonry chimneys. This not only makes for fewer chimney cleanings, but it also reduces the risk of a hazardous chimney fire!
  2. They are easier to access for cleaning, making it easier for the consumer to clean his or her own chimney, saving thousands over the years.
  3. They can be put up in hours as opposed to days, saving you hundreds, if not thousands in labor costs. 
  4. They can be installed in places where masonry chimneys simply cannot be.  Since they do not need to be anchored in the basement, your class-A chimney can start right under the roof of a cathedral ceiling, or they can start right at the ceiling of the first floor. Moreover, they can be offset to go around joists and rafters as needed. While they can run up the exterior wall of the house like a masonry chimney, any chimney will draft better and stay cleaner when it is inside the house. Plus, you receive the benefit of the heat off the interior chimney!

Mazzeo's stocks a premium grade of Class-A chimney made by Canadian manufacturer ICC Excel because it is made of more durable, corrosion-resistant material than hardware store brand class-A chimney, and it is listed to higher safety standard than products listed under the American safety standard. EXCEL is tested and listed to the ULC S-629 chimney standard. The ULC standard is generally considered the toughest residential chimney standard in the world and can withstand chimney fires three times longer than the American standard.  In addition:

EXCEL is the only 1 inch wall insulated chimney to pass the ULC standard.

EXCEL’s unique thermoplus insulation has an extremely high insulating value that helps to keep flue gasses hot. Creosote won’t condense in a hot flue.

EXCEL is the lightest weight insulated chimney of its kind on the market. This low thermal mass enables it to heat up quickly, reducing creosote formation. And EXCEL’s light weight helps make it the easiest chimney to install.

EXCEL incorporates continuous blanket insulation into a design which eliminates couplings between lengths, eliminating hot spots on the outside, or cool spots on the inside.

Your appliance manual or installation planning guide is your best source of information regarding the of your new appliance using a Class A Chimney System.

Mazzeo's stocks professional grade ICC Excel Chimney Class A chimney systems suitable for use on appliances that burn:

  • Wood
  • Oil
  • Coal
  • Gas
  • Charcoal

It is specifically engineered for wood burning stoves, fireplaces and residential furnaces.

Wood Stove Single Wall Stove Pipe

Your wood stove manual and installation guide is your best guide for selecting connector venting (stove pipe) and chimney requirements for your stove model. Connector pipe can only be used to connect the stove to the chimney, whether it be a Class-A chimney or a masonry chimney. It cannot be used to pass through floors, walls or the roof of your home.

Our stove pipe is made in Maine, and it is made of a thicker 22 gauge black steel than the typical 24 gauge steel stove pipe purchased at hardware stores or big box stores. 6" stove pipe is the most common size, and Mazzeo's stocks single wall pipe in various lenths and elbows.

Wood Stove Double Wall Stove Pipe

Double wall stove pipe is typically used to reduce the distance to combustible materials or when your stoves makes a rise of greater than 6' to the chimney by helping to ensure better draft. Mazzeo's stocks ICC's UltraBlack double-wall (type E) stove pipe in a variety of lengths and elbows.

There are four primary advantages to ULTRABlack over single wall connector pipes:

It offers reduced clearance to combustible materials.

It is designed to last the lifetime of the stove and/or chimney system.

It offers reduced creosote formation.

It is certified for use with mobile home stoves.

Mazzeos stocks 6" and 8" Ultra Black venting.

Direct Vent Gas Stoves & Gas Fireplace Venting

Direct vent gas venting is co-axial, meaning that it is a pipe inside of a pipe. The interior pipe is used to exhaust flue gases while the space between the inner pipe and the outer pipe is used to pull combustion air into the gas stove or fireplace. For this reason, direct vent gas stoves and fireplaces do not use combustion air from within the home. Unlike wood stove pipe and chimney, gas venting is used both as chimney and connector pipe, and is commonly referred to as "DV pipe". As with chimneys, components such as insulated wall thimbles, must be used in accordance to the manufacturers instructions. Gas stoves and fireplaces are always listed and approved to specified venting systems by type and by manufacturer, and components from various vent manufacturers should not be mixed. Mazzeo's sells direct vent gas venting from a variety of different manufacturers, and stocks ICC ExcelDirect Vent.

Co-Linear Aluminum Liners for Direct Vent Gas Fireplace Inserts

If you are venting a direct vent gas fireplace insert into an existing masonry chimney, you will not use co-axial direct vent pipe, rather you will use two aluminum liners, one for exhaust and one for combustion air intake. Aluminum liners tend to be less expensive than co-axial direct vent pipe, and Mazzeo's offers very affordable pricing on aluminum liner kits.

B-Vent Liners for B-Vent Gas Stoves 

If you would like to purchase a gas stove and vent it into an existing chimney, the state of Maine does not permit using the air space inside the chimney to draw combustion air.  Therefore, if you're considering venting a direct vent gas stove into a chimney, be prepared for additional venting costs as you will need to convert the venting system from co-axial direct vent to co-linear liners and back to co-linear at the chimney top.  Such conversions add hundreds to the cost of the installation, which is why we recommend that you consider venting a B-Vent gas stove into your chimney.  B-Vent gas stoves exhaust into your chimney via a single 4" aluminum liner, which is affordable and easy to install. Unlike direct vent gas stoves, B-vent stoves draw combustion air from within the room, thus the installation space must have adequate air volume.  B-Vent gas stoves, such as the Jotul GF 300 BV Allagash   and the Jotul GF 400 BV Sebago   are very popular here in Maine as many people do have chimneys and would like to make use of their existing hearth for a gas stove instead of a wood stove.  In this situation, a B-Vent gas is a great option. In addition, if the clay liner in the chimney is defective, lining it with 4" aluminum liner is much less expensive than relining it with an insulated, 6" steel liner. 

Pellet Vent

Pellet vent is used to vent pellet stoves and is used as both connector pipe and chimney. Mazzeo’s stocks EXCELPellet   by ICC, which:

  • Has a laser-welded stainless steel flue, which resists corrosion from all agricultural products, such as corn.
  • Has a laser-welded galvalume steel outer casing, which is much more corrosion-resistant than galvanized, and is designed to be painted.
  • Has a lifetime warranted, pure silicone gasket, which is 100% leak proof, eliminating the need for field application of silicone or cement.
  • Has a smooth, clean exterior finish that looks like single wall pipe.
  • Is very easy to paint in the field.