It's a question that needs to be answered - do you like your fireplace flues to be creamy or chunky?
Well, you know the difference. One has no crunch and the other does.
So, understanding the difference, looking up into this fireplace flue, which is it?
Creamy or chunky?
The chunky stuff is composed of soot and creosote.
Soot and creosote are a buildup of gases and "stuff" from wood that isn't heated up enough to exit the flue.
Instead it accumulates.
As it accumulates it gets thicker.
The fire department recommends that chimney flues be swept of such buildup when it accumulates to about 1/8" in thickness. Also, once cleaned, the flue can be inspected for other issues - movement and cracking and so forth.
At 1/4" thickness it is potentially flammable, and the cause of chimney fires. At that thickness you often smell carbon as well - burned toast more or less.
Oh, the harder the wood the hotter the temperature, so the slower the accumulation of buildup.
Pine, 2x4s, those cutsie little fire logs do not burn so hot, and so they contribute soot and creosote more quickly. And, I'm told, buildup of critical mass can be reached in as few as 10 or 12 fires! Harder woods not so quickly.
NEVER BURN PRESSURE-TREATED WOOD TO GET RID OF IT. IT CONTAINS DANGEROUSLY POISONOUS CHEMICALS. THROW IT AWAY INSTEAD.
AND, be sure to burn good, dried hardwood! That is defined as wood stored under cover for a year, and stacked in a crisscross pattern so it dries well.
A cord of wood is defined as 4'x4'x8' (think solid geometry). And it should be stacked in a side-by-side pattern. If the guys with the pick-up truck selling "dried" hardwood in your neighborhood want to stack it crisscross it is NOT a cord! And it's probably not dried either...
But, BUT!, pay attention to the thickness of any buildup in your flue! Chimney fires are NEVER a good thing. Have it swept professionally. Regular inspections and cleaning are a Best Practice! There are things advertised that you can throw in the fire, said to eliminate the buildup as they burn. But, sweeping is the recommended way to go. Ask your Fire Marshall.
My recommendation: yes, it requires that you peek your head in, preferably with a big-boy flashlight, and look up and see what soot and creosote accumulation you have. Your flue will appreciate your diligence. You want creamy, not chunky. FYI, should I show up for lunch - I happen to like the extra-chunky peanut butter on my sandwiches. It's more fun to eat! Oh, and jam, not jelly.
Jay Markanich Real Estate Inspections, LLC
Based in Bristow, serving all of Northern Virginia.
Office (703) 330-6388 Cell (703) 585-7560