In the Pioneer days, it was a tradition/ritual to take the stove out to the shop, disassemble it, clean everything to like new condition, replace any worn parts or hardware, reassemble everything, and apply a new coat of stove black prior to reinstalling the whole thing. Even in today's faster paced world, this is still the optimum approach. Below is a list of maintenance steps and considerations to get the most out of your wood-based heating system and keep it safe and operating properly when you go to use it next.
In addition to inspecting the stove itself, it is a very good idea to examine the entire pipe/chimney system top to bottom and inside and out. You are looking for several things:
- Soot/creosote buildup anywhere in the system. (One-eighth inch buildup or thicker anywhere in there means it's in need of cleaning. This is enough to be bad news in the event of a chimney fire.)
- Solid mechanical connections at all the joints. All smokepipe (the section between the stove and the actual chimney) joints require three screws, preferably stainless steel to avoid rust and make them easier to remove when it's time to replace pipe sections. Rusted, bent, or corroded sections must be replaced.
For metal factory-built chimneys:
- Factory pipe seams and joints need to be as new, not pulling apart or damaged. Any rusted or corroded sections should be replaced. All chimney sections of factory chimney ("triple-wall," "MetalBestos," "Class A," etc., whichever) need to be properly screwed or snapped together as specified in the original installation instructions. Loose joints are not acceptable. If in doubt, get your local chimney guru to show you what's right.
- Any flashing at roof or wall penetrations must be tight, solid, and sealed against leaks.
- The termination (cap) needs to be present and well attached. A spark screen is required by most codes and is a good idea to keep critters out of the chimney as well as keeping burning stuff in, rather than allowing it to escape and ignite your roof or the surrounding landscape. (The best spark screens are made of 3/4" expanded stainless steel mesh, as this provides proper protection and creates the least draft restriction.)
- If a factory chimney extends 5 feet or more above the roof penetration or other support, a roof brace consisting on two legs extending from the upper part of the chimney to the roof to form structural triangular support to prevent movement at the chimney top is required. Any chimney with such movement of more than about 1/2" should be supported, regardless of height above the highest support, in order to prevent degradation of the roof seal and any joints.
- In snow country, a "snow wedge" (or "snow diverter") should be installed on the roof above the penetration/roof jack to prevent snow and ice loads from damaging things.
For masonry chimneys:
- As above with respect to soot/creosote.
- Proper cap, as above.
Integrity of the masonry structure, including:
- Proper crown (concrete slab covering the top) 4" thick, and overhanging an inch or two past the vertical chimney wall. This provides a drip edge to let water fall off, rather than running down and soaking into the masonry structure, allowing opportunity for freeze/thaw action to damage the masonry.
- Solid mortar joints throughout the structure for structural integrity and to exclude water. (The best style of mortar joints are concave where the mortar meets the edges of the bricks and is tooled in a "C" shape in between. This helps to shed water.)
- All brick or block is intact, with no cracks or spalling (part of the face peeled off) and no missing sections.
- Flashing and counter-flashing present and intact. Proper flashing does not use "goop." The house and the chimney move independently, and a "goop" seal will fail every time. The best materials for flashing are stainless steel, copper, or lead because they will last longer than the rest of the house. Personally, I only like doing this stuff once per house! Search the web for "proper chimney flashing" for particulars. Jim Buckley has nice instructions here (http://www.rumford.com/chimneys/flashing.html).
- Chimneys wider than about 18 inches should have a cricket (the masonry equivalent of a snow wedge) on the high side to aid drainage and lessen buildup of assorted junk on the roof behind the chimney.
Hearth and mantel area:
- Verify proper clearances to pipe, stove, and any other combustibles, including your wood stash. A fire in the middle of your home can be a source of enjoyment and comfort for generations, and it is nothing to be afraid of. A healthy dose of respect, however, is well advised. Regardless of measurements, anything that gets hot enough that you cannot keep your bare hand on the surface comfortably at any time is too close. Wood that remains too close to heat for too long becomes "pyrolized," which means that the sap crystallizes and the ignition temperature drops to not much over 200 degrees F. Not a good idea in your living room…
- The off season is a good time to check the condition of the hearth and to repair any cracks and replace any missing pieces.
- A nice set of tools makes it easier to manage your fire and to keep things tidy. Forged ones cost a bit more, but will last for generations.
The following points will help you realize the most heat and enjoyment for your firewood investment:
- Maintain your supply at least a year or two in advance. Well-cured wood works way better than any other kind, regardless of species.
- Proper storage features a good cover and allows plenty of air circulation around all the ends of the pieces. Stacking with the bark up helps shed any water that gets into the stack. Having the stack on rails or pallets avoids rotten and soaked wood at the bottom.
- 16-inch lengths are often convenient, as 3 pieces laid end-to-end are 4 feet long – which makes it easy to calculate a 4 x 4 x 8 (128 cubic feet) standard cord – and also they will fit nicely in most stoves.
- Proper wood processing tools will save you time, money, and energy as well as making your whole experience much safer.
- Heat energy in wood is a function of weight. A pound of pine contains the same amount of heat as a pound of oak. (And also more ashes…) Wet wood still has all its heat energy, but it uses some (or a lot) to boil the water away before any gets out into the stove or the room.
- In a pinch, not-so-dry wood can be placed near the stove (careful, not too close or for very long –any that gets too hot to keep your bare hand on is too close.)
Starting, tending, and maintaining your fire:
- Tinder can be made from dryer lint, very small scraps from around your wood processing area, and many other assorted bits of stuff that can be easily gathered. (A product called "fatwood" can be lit with a match, and burns hot and long enough to start your fire easily, although it is a bit pricey.)
- Your scraps from your splitting area make excellent kindling.
- Full rounds in a small enough diameter to fit about 3 snugly in your firebox over a nice bed of coals will often help a fire hold overnight. (If your fire won't last overnight, drinking a large glass of water just before going to bed can help you remember to get up during the night and stoke the fire on your way by…)
- With stoves that have a damper in the smoke pipe, use the damper to slow the fire down to your desired temperature. If you use the air inlet, it produces a rich burn that wastes fuel and dirties the chimney faster. Newer stoves are designed to operate without this damper, and will still burn clean at low settings, although the fire may not last quite as long between loads of wood.
- Our perception of comfortable temperatures is a function of a combination of temperature, humidity, activity level, and some other stuff. A kettle of water on top of the stove, on a trivet that keeps it from overheating and boiling, will raise the humidity in the house and make it feel warmer even at a slightly lower temperature, which saves a bit of wood.
Random final thoughts…
- Cast iron stoves maintain more even heat and can last much longer than steel ones.
- Catalytic combustors in wood stoves are for the most part very expensive consumable "band-aids" to lower emissions (wasted fuel) in poorly designed stoves.
- A wood burner establishes a very nice rhythm (mantra?) in a home. The "cave person" factor is profound and powerful, in my experience…
- A log that rots in the forest gives off exactly the same emissions as one that burns in your stove. All of it is then incorporated back into the normal life cycle of the planet. The only difference is how long the process takes. (Unless, of course, you and your 50 closest neighbors are all down in a holler with your stoves damped way down in the middle of a severe inversion…)
- Those who clean and service their stove/chimney in the summer are ready to go on that first cool evening in the fall, rather than having to play catch-up or wait for the swamped chimney sweep to fit them in…so don't put it off!
~ Ed Williams
Ed Williams and his son, Eli, have been installing and caring for chimneys and their owners for over 35 and 22 years, respectively. Our service area includes most of Utah and parts of Wyoming and Idaho. Please feel free to contact us if you have any questions, observations, or interesting stories related to heating with wood.