By Matt Menke
What better to do in the hottest month of the year than think about making things warmer? After a few mild winters, it’s easy to forget about the cold snaps still in store. But now is the time to prepare for those lovely, crackling fires we’ll enjoy in the future. This is not a joke; chimney sweeps are available now but will be fully booked when everyone rediscovers wood fires at the same time. There’s time for repairs and budgeting while it’s warm outside.
A full inspection of your wood-burning system, from the fireplace up to the chimney cap, is a specialized job for a chimney sweep. A traditional home inspection, though, looks at all the elements anyone with a fireplace would be wise to get to know. So here is some basic information including a look at red-flag issues that signal it’s time to call in an expert. This list is not a substitute for a full inspection by a professional, though, as some problems can be easy to miss. And if the house is new to you, an inspection and cleaning is a must.
Creosote is the cocktail of unburned organic material that sticks inside your chimney. It may appear shiny black or as a shaggy brown layer. All it takes is an unusually hot fire or stray spark to ignite creosote buildup that’s only ⅛ inch thick, creating a hot chimney fire that endangers your home. A cell phone’s flashlight makes it easy to check for buildup; point a strong light up your chimney and find an angle that helps you take a good look up the flue. Creosote also collects at the roofline, where the chimney is exposed to cold air on all sides, and that may be where you need a professional to check. If you have more than a few fires each winter, it’s best to have the chimney cleaned every year.
The safest fire is the one that’s the same every time, consistent, with no surprises, like your morning cup of coffee. Get to know your firewood. Make sure your hardwood logs (like oak and hickory) are covered and have at least a year to dry before you use them. Dry hardwoods burn well and leave very little creosote; wet wood or softer species (like pine) burn cooler and create far more buildup. Find a reliably quick way of kindling your fire, and getting it up to temperature as quickly as possible. Smoky, slow-starting fires deposit creosote regardless of what wood you use. Learn to use the air vent to ramp up and control your fire. Wood stoves and inserts often have a thermometer and the manufacturer’s recommendation for an ideal fire temperature, while traditional masonry fireplaces have neither. The goal is to- aim for a steady, strong flame with no roaring and no smoldering.
It’s important to have sufficient distance between the hot parts of your system and anything flammable. A hearth at least 16 inches wide will protect your floors and woodwork from stray sparks, and using a fireplace cover with a spark screen can be a big help. Manufactured fireplaces will each have their own set of recommendations in the manual. As a rule of thumb, wood stoves should stand at least 36 inches from flammable surfaces, even curtains and wood walls. Installing a heat shield reduces risk, but safety measures are still critically important. Even the wood frame that held the wet mortar for your hearth is often still in place, which can leave your mortar vulnerable to cracking.
The mortar that holds your masonry together is an incredible material, but it isn’t indestructible. Freeze/thaw cycles can break the material down. You may see cracks or separated bricks at the top of the chimney, brick faces popping off partway down the chimney, gaps between tiles in the firebox or cracks in the hearth itself. Those gaps accelerate chimney damage and can allow sparks to hit the wood framing. Cracks can also allow normal combustion gasses to filter back into your home. It’s important to hire a chimney professional to evaluate and fix cracks and gaps.
If you didn’t grow up around campfires and hearths, you may have never felt the need to learn the basics of fire safety. If you’re unsure about using your system it is always best to turn to a chimney sweep to be safe. Taking the time this summer to learn a new skill may seem challenging, but it could make the warm fires in the dead of next winter all the more rewarding. While a gas fire may make a classic hearth seem outdated, nothing can replace the authenticity of an old, crackling fireplace.