Safety precautions for wood stoves in tiny spaces
Since launching Tiny Wood Stove, I’ve spent a lot of time talking to folks in the tiny living community. My family and I live in a tiny space ourselves, and I love to see what other folks have done with their spaces. I’ve seen hundreds of tiny houses on wheels, skoolie conversions, off-grid cabins, yurts, modern and vintage RVs, and vans set up for full time living. I’ve seen some amazing builds incorporating wood stoves, and a few that made me nervous.
Just because others are showing off pictures of stove installs online does not mean they are safe, or that they work well. I did a lot of research before doing my own DIY stove install, and I still managed to make mistakes of my own.
CHOOSING THE RIGHT SIZE STOVE
Our original wood stove was a bit too big for our Airstream, but some of the stoves I see in small spaces are massively oversized. If your stove is too big for your space, you’ll either have to choke it way down to keep it from overheating your space, or open all the windows. Opening the windows in the Winter wastes fuel and somewhat defeats the purpose of heating. Choking a stove down too far can cause it to burn inefficiently, which wastes fuel, pollutes the air, and can cause dangerous amounts of creosote to accumulate in your flue system. It’s best to choose the smallest stove that can adequately heat your space, so you can burn hot and clean fires every time you use your stove without making your living space uncomfortably warm.
DESIGNING A GOOD FLUE SYSTEM
Poor flue design or improper materials are pretty common to see in DIY installs. When I first bought our wood stove, it didn’t come with any flue pipe or instructions. The company I bought the stove from suggested I source flue pipe locally, but as it turns out, solid fuel rated stovepipe wasn’t available in North America in sizes any smaller than 5”. At first, I made the mistake of using pellet pipe (as suggested by the distributor!) instead of solid fuel rated stovepipe. It gave off an awful chemical smell every time we used the stove. I soon learned that pellet pipe can gas off its zinc coating at around 570 degrees, and I was measuring flue temperatures as high as 800 degrees F. The resulting search for proper solid fuel rated stovepipe was the catalyst for starting Tiny Wood Stove. Once I installed the correct pipe, the chemical smell was gone, and I could feel good about using our stove in our small space with my wife and young children. To this day, there are companies that sell small wood stoves in North America with no plan whatsoever for providing the flue parts needed to install them. Fortunately, most of their customers can now find the correct parts from Tiny Wood Stove.
OBSERVING PROPER CLEARANCES
The other mistake I see frequently is clearance violations. On my most recent trip to a tiny house festival, I toured a beautifully constructed tiny house on wheels with a small antique stove installed in the kitchen. Antique stoves don’t tend to come with installation instructions, so clearance violations were no surprise on this DIY install. There was no hearth under the stove, and the back of the stove was about an inch from a combustible wall with no heat shielding. I suspect the stove was never actually used, but if it were, it was only a matter of time before it caused a fire. A spark is not necessary to start a fire, only fuel, air, and sufficient heat. Combustibles that violate stove clearances will deteriorate over time as they’re exposed to excessive heat, and their ignition temperatures will slowly drop. At some point, possibly after years trouble-free use, a fire can start without warning. Clearances need to be respected to avoid catastrophe.
PROVIDING A FRESH AIR SUPPLY
Natural draft stoves use quite a bit of fresh air to feed combustion. If there isn’t enough air leakage into the space through cracks around doors and windows, the stove won’t be able to burn efficiently.
Having insufficient ventilation with a wood stove is somewhat less dangerous than with a catalytic heater, since a wood stove exhausts outside and can’t deplete the oxygen in the room without also filling the room with smoke. Smoke in the living area is potentially dangerous, but it’s much easier to notice than oxygen depletion that could occur with a non-vented propane appliance. Difficulty lighting or maintaining a fire is usually the first sign of a poor air supply. If smoke is spilling out of the stove, you’re likely to see and smell it, and your smoke and CO detectors are also likely to detect it.
If your small space is relatively airtight, you might need to add a fresh air supply for the stove. Some stoves have optional direct air kits, which allow you duct outside air to the stove’s air intake. Using a direct air kit not only ensures the stove will have enough air to burn efficiently, but can minimize cold drafts at doors and windows caused by your stove pulling your warm air out of the living space.
Stoves get HOT while in operation. To keep from burning yourself, you should have a hot mitt, a set of stove tools, or a pair of welding gloves to use while stoking the stove. If you’ll have very young children in your home, it’s a good idea to think through how you might keep them away from the stove so that you don’t have to play goalie whenever they’re toddling around. By 5 or 6, most children have the reasoning skills to know not to touch the stove, and the balance to avoid it without a barricade, but you should always supervise young children around a hot stove.
Whether you have a wood stove or not, you should always have at least one functioning smoke detector, carbon monoxide detector, and fire extinguisher in your space. Smoke tends to rise, so mount the smoke detector on or near the ceiling. Carbon monoxide tends to mix evenly with the air in the room, so mount it close to eye level, so you can see the screen. Fire extinguishers should be installed near an exit away from a potential source of fire, so you don’t have to move toward the fire to reach the extinguisher, and you can continue to retreat out of the building if necessary.
By buying the right stove for your space, installing it on a fireproof hearth with proper clearances, and using solid fuel rated stovepipe, you can have peace of mind and years of safe, efficient heat for your family to enjoy.