How quickly a chimney gets dirty has less to do with the chimney than with what is burned in it and how. AM Chimney Sweep cleans, inspects and repairs chimneys in Bernardsville. For households that use their fireplaces often, the habits on this page will do more to keep a flue safe between sweepings than anything we can do on the day.
A borough of houses with fireplaces
Census Bureau estimates show that close to nine in ten Bernardsville homes are detached single-family houses, and about a quarter were built before 1940. Older and larger houses often have more than one fireplace. About one home in ten here also heats with oil, which has its own flue to look after.
Source: U.S. Census Bureau, American Community Survey 2020–2024 five-year estimates.
Firewood: the 20 percent rule
The U.S. Environmental Protection Agency’s Burn Wise program puts it simply: wood burns best at a moisture content below 20 percent, and it should be seasoned for at least six months. Freshly cut wood can be half water by weight. Burning it spends the fire’s heat on boiling that water off, and the cool, steamy smoke that results is what coats a flue.
- Split it. Wood dries from the cut faces, not through the bark. Split logs season far faster than rounds.
- Stack it off the ground, in a single row if possible, where wind and sun can reach it.
- Cover the top only. A tarp over the whole pile traps moisture.
- Give dense hardwoods longer. Oak in particular often needs well over one season.
- Test it. An inexpensive moisture meter pushed into a freshly split face gives a reading. Dry wood is also lighter, has cracked ends and rings when two pieces are knocked together.
Source: U.S. EPA Burn Wise, “Best Wood-Burning Practices.”
What not to burn
EPA’s list includes household trash, plastics, treated or painted wood, plywood and wet or moldy wood. These can release harmful chemicals and leave heavy deposits. Cardboard and wrapping paper are best kept out too, since they send burning fragments up the flue.
How you build the fire matters
- Burn hot and bright. A lively fire with visible flame sends hot smoke up quickly. A dull, smoldering one produces the most creosote.
- Do not overload the firebox to make a fire last. Add a log or two at a time.
- Avoid damping a fire down to hold it overnight. Let it burn out.
- Look at the chimney top from outside. Once the fire is going, there should be little visible smoke. Thick smoke means wet wood or too little air.
Large fireplaces, large flues
The generous fireplaces found in many older houses have correspondingly large flues. A big flue stays cool unless the fire below it is substantial, so modest fires in a large fireplace can deposit more than you would expect. It is one reason these chimneys are worth checking every year even with moderate use.
Ashes
- Leave an inch or so of ash on the firebox floor during the season. It insulates the coals and helps the next fire.
- Coals can stay hot for days. Put removed ash in a metal container with a tight lid.
- Store that container outdoors, on a non-combustible surface, away from the house, the deck and the woodpile.
- Clean the firebox out completely at the end of the season. Ash draws moisture in summer and is hard on the firebrick and the damper.
Keep track of which fireplaces you use
In a house with several fireplaces, each has its own flue and its own history. Note which ones were used and roughly how much. It lets us tell you which need sweeping and which only need inspecting, and the unused ones still need a cap to stay dry.
When to have it swept
Yearly inspection is the standard. Sweeping is due when deposits reach about one-eighth of an inch, or sooner if there is any shiny glaze. If you burn most days in winter, plan on a cleaning every year and ask us to look partway through the season.
Beyond cleaning
Heavy use shows up first in the smoke chamber, the damper and the flue tiles. We check all three on every visit and photograph anything that needs attention.
Schedule service in Bernardsville
Call (862) 225-6529 or send a request online. Completed projects are shown in Our Work, and we serve the surrounding towns throughout North Jersey.