www.pineandlakes.com
The entire area has changed big time. Unrecognizable in many respects.
Indeed. Several years ago I had a run-in with wet maple. The stacks had gotten wet in places due to a leaky tarp. It was all we had to burn. This wood gunked up our flue system in 3 weeks. Fortunately, I caught it early enough to avoid a chimney fire, but this is the dirtiest our flue has ever been. Now, if the wood is not ready, we won't burn. We now have a proper wood shed and this has not happened again.
I first thought "Well, they look pretty smiley about the whole thing." Next thought was "Or maybe somebody just said 'Hey, chief, when was the last time you swept your chimney?' " 😏 To which he replied "I never sweep, I just burn it out." 😆The guys may not let him live this one down for a while.
I know just what you are saying about "overbuilt". Ours is a 6'x3' chimney with only one flue, which is offset towards the outer chimney wall. Physics says no way can there be a problem with clearance to combustibles causing a fire, but code is code so I insulated it.
Almost all the house fires I've been to that have started from chimney's have been from the exposure catching fire from radiant heat from the chimney, either cracked masonry, class a pipe failure (old pipe that has become compromised, then fails)
That’s the thing, fire can start on the outside of a house, go unnoticed, hit the soffit and enter the attic still unnoticed and then self vent through the roof grabbing everyone’s attention between the bright flames, heavy smoke, crackling noises and sounds of light weight trusses failing and hitting the ceiling below.
This makes sense, but it's easy for me to picture how expanding creosote and embers shooting out the stack like a volcano can burn thru asphalt roofing and start a roof fire as a primary cause, but I'm no expert. From what you posted earlier, it sounds like most house fires are not due to chimney fires, but more likely from compromised liners during a normal burn.
so your assumption of the liner failure as the initial point of origin I understand but…. A chimney fire is the point of origin. If pyrolysis has occurred is lowers the combustion temperature of the affected combustibles. Through repeated high temperature exposures. The could happen with a liner that is still functionally intact but missing insulation awhile being run within design limits. Thick 1000 degree liner touching masonry that is touching combustibles.
Physics and real life experience says say most fires from chimneys are due to lack of clearance to combustibles. Usually at the wall passthrough but it absolutely happens at the chimney
Absolutely not. The temps are typically not high enough to cause ignition through the masonry under normal operating temps.
Most class a failures aren't from both wals of stainless rusting or burning through. They are from compromised insulation or failed connections. I just cleaned one last week where the inner wall and insulation was almost all gone from the tee and first section of pipe. The customer said oh yeah pieces came out a couple years ago but it was still working fine🤦♂️🤦♂️
Ok so bottom line , Chimney fires cause extreme excess heat radiated from an intact liner, and the insulation protects the combustible structure from the short term excess heat. Long term, the insulation prevents pyrolysis so when a chimney fire does occur, the wood has a higher ignition temperature to start with. I'm surprised sparks,embers aren't a big problem.
Where the crock passes through a combustible wall to get to the chimney. They are almost never done properly
