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Wednesday, January 20, 2021

What Mark Twain Said About Masonry Heaters

Mark Twain (Samuel L. Clemens) discovered masonry heaters while traveling through Europe and realized that America was far behind the times. In 1891, Twain devoted several pages of his book, "Europe and Elsewhere" to the masonry heater and pleaded for its introduction to America:

“Take the German stove, for instance – where can you find it outside of German countries? I am sure I have never seen it where German was not the language of the region. Yet it is by long odds the best stove and the most convenient and economical that has yet been invented.

To the uninstructed stranger it promises nothing; but he will soon find that it is a masterly performer, for all that. It has a little bit of a door which you couldn’t get your head in – a door which seems foolishly out of proportion to the rest of the edifice; yet the door is right, for it is not necessary that bulky fuel shall enter it. Small-sized fuel is used, and marvelously little of that. The door opens into a tiny cavern which would not hold more fuel than a baby could fetch in its arms. The process of firing is quick and simple. At half past seven on a cold morning the servant brings a small basketful of slender pine sticks – say a modified armful – and puts half of these in, lights them with a match, and closes the door. They burn out in ten or twelve minutes. He then puts in the rest and locks the door, and carries off the key. The work is done. He will not come again until next morning.

All day long and until past midnight all parts of the room will be delightfully warm and comfortable, and there will be no headaches and no sense of closeness or oppression. In an American room, whether heated by steam, hot water, or open fires, the neighborhood of the register or the fireplace is warmest – the heat is not equally diffused throughout the room; but in a German room one is comfortable in one part of it as in another. Nothing is gained or lost by being near the stove. Its surface is not hot; you can put your hand on it anywhere and not get burnt.

Consider these things. One firing is enough for the day; the cost is next to nothing; the heat produced is the same all day, instead of too hot and too cold by turns; one may absorb himself in his business in peace; he does not need to feel any anxieties of solicitudes about the fire; his whole day is a realized dream of bodily comfort.

America could adopt this stove, but does America do it? The American wood stove, of whatsoever breed, it is a terror. There can be no tranquility of mind where it is. It requires more attention than a baby. It has to be fed every little while, it has to be watched all the time; and for all reward you are roasted half your time and frozen the other half. It warms no part of the room but its own part; it breeds headaches and suffocation, and makes one’s skin feel dry and feverish; and when your wood bill comes in you think you have been supporting a volcano.

We have in America many and many a breed of coal stoves, also – fiendish things, everyone of them. The base burners are heady and require but little attention; but none of them, of whatsoever kind, distributes its heat uniformly through the room, or keeps it at an unvarying temperature, or fails to take the life out of the atmosphere and leave it stuffy and smothery and stupefying….”

Masonry heaters are site-built wood-fired masonry appliances that produce heat - and lots of it. They are much more efficient that any high-efficiency wood-burning stove and last for many years. Here it is more than 100 years after this article was written and few Americans have grasped the concept.

Visit for more information about masonry heaters. Visit the Masonry Heater Association of America site for a list of heater masons.


 Marge Padgitt is the author of Wood-Fired Heating and Cooking, and the president and CEO of HearthMasters, Inc. dba Padgitt Chimney & Fireplace in Kansas City, Missouri. 

Masonry Heaters are the Best Option for Heating with Wood

By Marge Padgitt

Look no further than a masonry heater to heat your home during a long cold winter. Use this appliance as a primary or supplemental source of heat, and feel good about it, too, since masonry heaters are GREEN. Masonry heaters have been around for hundreds of years in Europe and are finally catching on in North America and other parts of the world. People needed to heat their homes in an efficient manner in olden times just as today in order to save their forests. Inefficient open fireplaces took too much of their valuable resources, so another method had to be developed. No one knows who the first mason was who came up with the idea of something that would retain heat for long periods of time, then radiate it into the home while using much less wood, but whoever he was he was a genius. 

Masonry heaters have been redesigned and altered over the years by different masons in Finland, Russia, Germany, Austria, and the United States. But heaters all have the same characteristics with complex channels to slow down and trap heat from flue gasses, and a mass of masonry to retain that heat, then radiate it to the living space over a period of up to 20 hours. By the time the products of combustion get to the exit of the flue, the smoke is white or clear, and the particulate emissions are very low. One load of wood can usually provide heating for the average size home for 8-12 hours. Masonry heaters use approximately 1/3 the amount of wood as a high-efficiency wood stove to produce the same amount of heat. Compared to even the best high-efficiency wood–burning stoves on the market today, gas and oil-fired furnaces, and certainly inefficient open fireplaces, masonry heaters cannot be beat. Homeowners may wish to use a masonry heater as their sole source of heat, or in conjunction with another system.

Natural stone masonry heater
by Gene Padgitt

Another benefit masonry heaters offer is that they do not require electricity, gas, or ductwork to distribute the heat. In a properly designed home with an open floor plan and the heater in the center of the home, the heat will radiate evenly throughout. Ideally, heaters are built in new home construction, but they can be added to existing homes as well. If planned in a passive solar home, the masonry mass of the heater will also absorb and radiate heat from the sun. Heaters require a suitable foundation to support the massive masonry, which weighs three to six tons by the time all of the firebrick, block, cast iron doors, dampers, and exterior masonry facing is installed. 


Heaters can be enhanced with heated benches to sit on, mantels, wood storage bins, and even bake ovens. Pizza and bread from a wood-fired bake oven has an incredible and unique taste that is not to be missed, and entire meals can be cooked in the oven if desired. An experienced heater mason can not only design and build the right size and type of heater for a home but make it beautiful to look at as well. An exterior finish of soapstone, tile, natural stone, stucco, or brick can make a dramatic statement. Heater masons will work with the homeowner to come up with a custom design that suits the home or use one of many masonry heater kits that are available from several manufacturers (usually incorporating soapstone) in a variety of designs.  

Use of natural non-toxic materials and the renewable resource of wood make masonry heaters the perfect solution for a green home. 

The trade is very specialized, with only a few professional heater masons scattered across the world. Fortunately, most of these masons will travel to do installations. Often several heater masons will help each other out since these are big projects. In days of old, the heater masons kept their trade secret, even to the point of not leaving the room until the heater was finished so no one else could see how the interior was built. At that time, the livelihood of the masons was dependent on this secrecy. The trade is so skilled that the only way to learn is to do hands-on assistance with an experienced heater mason, and that is part of the reason the Masonry Heater Association was formed. The older masons do not want this to become a lost art, so they help train others. The Certified Heater Mason program was developed by the experienced MHA members in order to assure that the knowledge is not lost. 

In the U.S. most people are not yet aware of masonry heaters, so it is a challenge for a heater mason to make a living out of just building heaters. Most heater masons also build other types of projects such as fireplaces, chimneys and outdoor bake ovens. Some are timber frame or log home builders or own brickyards. Most are very aware of the green building trend and are interested in sustainable living. Many heater masons will travel to build a heater because they love doing it, and because they love the satisfaction they get out of building something that is very specialized.

Pricing for heaters is what most would consider being on the high end, and a long-term investment. The average cost a homeowner may expect to pay is from $25,000 to $60,000, with price depending on the complexity of the heater, material costs, and labor.  The expected time to get a return on your money is approximately 10 years. The time to build a completed heater may be more than four weeks, depending on how many skilled craftspeople are working. Many homeowners will elect to be an assistant on the job in order to lower their costs. In some cases, if a heater mason is traveling the homeowner will put him and his assistants up at their house or a local hotel. When traveling the masons usually work long hours in order to get the project done as quickly as possible.

Find out more about masonry heaters, including technical specifications and testing results, photos of heaters, manufacturers, and a list of heater masons, contact the Masonry Heater Association of North America through their website at or call the executive director, Richard Smith at 520-883-0191.


Marge Padgitt served on the board of directors for the MHA and the National Chimney Sweep Guild. She is the author of “Wood-Fired Heating and Cooking.” Marge is president and CEO of HearthMasters, Inc. dba Padgitt Chimney & Fireplace in Kansas City, Missouri. Her husband, Gene Padgitt, is a Certified Heater Mason. Contact her at,, or 816-461-3665.  



Friday, January 8, 2021

What is a Flue Liner and Why do You Need One?

Flue liners are an important part of any furnace, water heater, boiler, or fireplace system. Liners have been required by code since 1927, but have been in use since the 1870’s. In a nutshell, the purpose of a flue liner is to keep toxic flue gasses such as Carbon Monoxide, other aldehydes, and tar vapors inside the flue and allow them to exit the house. It was found early on that with masonry chimneys, the mortar joints tend to deteriorate over time and develop cracks and gaps that allow gasses to leak through them. So, liners were invented. Vitreous clay tile flue liners were created to line the interior chimney so that flue gasses could not escape the flue. This is extremely important for the health and safety of the occupants of a home.

However, over time, rainwater, moisture, and acidic flue gasses eat away at mortar joints between the liner sections. Clay tile flue liners are made in two-foot sections and installed ahead of the exterior masonry chase. They have a bed of mortar between each section. When these mortar joints erode, they create gaps between the liner sections – and we are back to square one with toxic gasses leaking into the house. 

A liner has been removed and one remains

When rehabbing a house, a contractor may find that there is no liner installed in a masonry chimney. This is more common in older homes with utility flues serving heating appliances and water heaters, but occasionally is found with fireplaces as well. It is extremely common, however, to find a flue liner with missing mortar joints. This can be remedied in most cases with a method using a ceramic joint filler, which is applied using a heavy-duty vibrating bell sponge while pouring the mix from above the flue liner. It involves special equipment and trained professionals to do the job. In cases with large gaps between liners this method cannot be used, and relining is necessary.

A second common issue with flue liners is incorrect sizing. If a liner is not correctly sized to the appliance, smoking or backup of toxic gasses can result. This often occurs when a high efficiency furnace is installed, leaving a water heater to vent on its own, which it cannot do in an oversized flue. A liner for the water heater will be necessary unless a replacement water heater that vents out the side is used instead. An incorrectly sized flue liner serving a fireplace will cause backup of smoke and toxic gasses into the home.

Stainless steel liner with a single flue tile on top
The third common issue with clay tile flue liners is damage from a chimney fire. As fireplace inspectors we see this on a daily basis, and in most instances, the homeowner had no idea that they had a chimney fire unless they caught it at the time, or a neighbor knocked on their door after they saw flames shooting out of the chimney. Most chimney fires are of short duration because as flammable creosote burns it expands to ten times its size and snuffs out the fire. But even a short duration chimney fire can cause a lot of damage to flue liners, usually leaving vertical and sometimes horizontal breaks behind. These breaks open to as much as ¾” when the appliance is used, once again allowing gasses to escape. The only solution is to reline the flue. Fortunately, homeowner’s insurance covers chimney fire damage since it is considered a “hostile” fire. If a home was purchased within 12 months prior to finding the damage the new owner may have recourse with the seller, who can file a claim on their insurance. Chimney repair can be expensive, and the last thing a new homeowner wants is a huge un-budgeted-for expense after a home is purchased. This is why an inspection of all flues in a home is so important prior to purchase. 99% of Home inspectors do not inspect chimneys, only a chimney sweep with the proper equipment can, and should, do a chimney inspection using a chimney camera system. If timing does not allow for an inspection, figure in extra cost in your rehab estimate based on the size of the chimney.

Clay tile flue liners being installed as masonry is built up
Relining involves removal of the cement cap and extraction of the clay tile flue liner, installation of a replacement stainless steel liner with insulation, and rebuilding the cement cap. Other demolition such as removal of a damper casing, firebrick, or a wall may be necessary. Smoke chambers are often in poor condition and need to be parge coated with insulating mortar.  It is important to use a liner with the same I.D. dimensions as the previous liner, or in some cases, larger, and the only way to do that is to take the old liner out first. In rare cases, the flue is oversized so installation of a new liner may be possible without extracting the old liner.

Codes must be followed with flue liners – Chapters 10 and 18 in the International Residential Code cover most of this information, and the National Fire Protection 211 Standard for Chimneys, Fireplaces, Vents, and Solid Fuel Appliances also applies since it is the industry standard. We also follow the NFPA 54 National Fuel Gas Code.

A stainless steel flue liner being prepped   

A professional chimney contractor should do this type of work since they are familiar with the codes and standards and have the equipment and expertise to do the job. In the greater Kansas City area and other jurisdictions across the U.S., a Class DM Master Mechanical (HVAC) Contractor License is needed in order to reline flues, and a permit is required for the work, with an inspection by the building codes inspector.


The cost to reline a flue can very greatly and is determined by the type, size, and length of liner needed and difficulty level of the job.


Marge Padgitt is a 35-year chimney industry veteran. She trains professional chimney technicians across the U.S. and is the author of The Chimney and Hearth Pro’s Resource Book, and Wood-Fired Heating and Cooking, along with many training DVDS and presentations. Contact her at, 816-461-3665, or