Are Home-built (DIY) Wood Burners Safe?

I have built two wood burning stoves for my own use and currently heat my home with a stove that was built from scratch. I have researched different types of DIY stoves including kits, plans, and simple idea sites for wood burners. Here is the result of my work and research.

Are home built wood burning stoves safe? The great majority of plans for wood burning stoves are targeted for the outdoor or out-building heat type of stove. The stoves as designed are safe but only as safe as the builder has constructed them.

EPA Regulations

In the mid-1980s when wood-burning stoves started showing up in homes and garages, the EPA took an interest in the smoke that was coming out of chimneys all over the United States. These new-fangled stoves were designed to control the air flow into the firebox, and with that great power, could also regulate the temperature of the fire, and the temperature of the room or rooms they were heating.

As the stoves were limiting the amount of air that was feeding the fire, the smoke had an increased amount of PM or Particulate Matter rising with the smoke. The EPA decided that the manufacturers of wood burning stoves starting in 1988 had to meet requirements that reduced the amount of PM that left the stove.

Since home built stoves are not built by a registered manufacturer, they do not have to comply with the regulations. If you plan on building your own wood burning stove and would prefer to comply with the EPA, there are some plans available to add a catalytic converter to your heater.

If you do plan on building a wood burning stove that is intended for inside a home, the welding portion of the work should be completed by a trained professional. The smoke in the firebox needs to stay in the firebox and not be pulled by a blowing unit into a room where you may be working, living, or sleeping.

That could become deadly in a short amount of time. Also, even a good weld can break after years of heating and cooling cycles. After hundreds of those cycles, a poor weld, or the metal next to a bad weld could break leaving a small crack in the firebox.

Types of Home Built Wood Burning Stoves

There are many types of home built wood burning stoves. Let’s take a look at a few of the most popular.

Barrel Stove

A barrel stove is just what the name suggests. It is built from one or two 55 gallon drum barrels. You can find multiple kit versions of these, and they will usually come with four to seven parts.

The single barrel version will generally include a door, two legs, and a chimney. You must supply the barrel and a chimney. The double barrel version has the same as the single version plus two additional legs to mount the barrels together and a connector pipe.

The advantage of the two barrel system is the additional heat that is radiated from the smoke as it passes through the top barrel. Barrel stoves are generally used in garages or outbuildings.

Barrel systems are popular due to the low cost of the materials and the ease of building the completed product. The downside of a barrel wood burner is the thin wall of a 55-gallon drum. The wall thickness is only .0324 inches. The barrel will burn through at some point.

To be safe, take a flat piece of metal and tap on the barrel where the fire burns the hottest (when it is cold). Any weak spots will reveal themselves in the sound and the feel.

Propane Tank Stove

A propane tank has a much thicker wall than a 55-gallon drum, but most are pretty small in diameter. If the area you are heating is small, then it may be a great start for your stove. It will take some skilled cutting and welding to add a door, legs, and a chimney. Some of the designs are unique.

Hot Water Tank Stove

A hot water tank could make a very large wood burning stove. Again the welding and cutting skills need to be above average, and if the tank has had more than ten years of water in it, the bottom might be a little suspect to rust.

A thorough inspection of the bottom of the tank would be the first item of business. Unless you are very creative, a hot water tank stove will not be much to look at. This type of stove is an outbuilding or garage only heater.

Home Built from Scratch Stove

The wood burning stove from a pile of steel will require not only a specific set of mechanical skills but some detailed planning. From the firebox to the doors and how the air is controlled all need to be addressed before any steel is purchased. The placement of the pipe for the chimney is also dependent on where the chimney will exit the building it is placed in.

The firebox welding must be perfect in an air-tight system, especially if an air jacket (air around the stove to be used for heating) will be built into the stove. The door must also be set up to close and seal the stove off. If creosote on the walls ever catches fire, the door and air vents must be able to shut tight enough to stop all air from entering the firebox.

The thickness of the firebox walls must be determined. A wood stove firebox will be constructed of .250 inch steel or 1/4 inch. This makes wood stoves extremely heavy even before the fire brick is installed!

Chimneys

Chimneys are the most important element of the entire wood burning stove system. You regulate the fire by allowing the correct amount of air in the firebox and adding the desired amount of fuel (wood). If a fire occurs in the home as a result of the wood burning stove, it starts in the chimney.

The chimney must be able to handle the amount of smoke that will leave the wood burning stove and guide that smoke up and out of the building where the stove is located. That sounds oversimplified, and it is, but it is extremely important.

Each type of chimney is also rated for a specific amount of heat on the inside wall and the outside wall. You may not know how hot your stove will burn so pick the chimney that will work with the highest heat. A double wall chimney will be rated for up to 2300 degrees F.

Safety

The formula for the size (diameter) and height of a chimney can be found in the NFPA 211 standard. This standard will also provide additional information on safety when it comes to the size and materials that should be under and around a wood burning stove. It also specifies the setback from corners and walls.

Building a wood burning stove can be a rewarding endeavor. The heat provided may heat your home or a workshop on a frigid winter day. But, it is not worth cutting corners when it comes to the safety of you or your loved ones. Look up the regulations and follow them to keep from causing an accident that is preventable.

Additional Questions

How to size a wood burning stover for the area you are heating? Manufactures websites have charts on the BTU output of their stoves. Using the manufactures firebox size (cu. in.). Size your stove to meet the required output.

How to clean the outside surface of a wood burning stove? A simple vinegar mixture can clean the surface of a wood stove. There are a number of products on the market that can restore a wood burning stove to its original black matte finish.