Hearth Horror Stories

Proper Installation and Maintenance is Vital

In our service business, we often run into situations that serve as cautionary tales. If a hearth appliance is not installed by a knowledgeable, licensed professional, the results can be seriously unsafe, both for you and for your home. Below we have some problems we’ve run into and the suggested solutions.


fire damageClearances to Combustibles
This is what happens when clearances to combustibles are not respected! The stone that covers combustible wall board–or tile or any other noncombustible–does NOT (contrary to popular belief) reduce clearance to combustibles with a wood, gas or pellet stove. In fact, stone is an excellent conductor of heat! Proven by what you see in this photo of the inside of a chase. What happens is a chemical process called pyrolysis which changes the chemical composition of the wood in a way that dramatically reduces the temperature required to produce combustion–from 250 degrees F to as low as 170 degrees. Temperatures on the surface of a wood stove can easily reach 300 degrees. Spontaneous combustion occurred, and here you see the result. It was very fortunate that someone was at home at the time of the fire.
horizontal pipeHeavy Creosote Buildup
This installation has an eight-foot vertical section of stovepipe which turns and enters the flue at 90 degrees. This section is the four-foot-long piece of stovepipe that made up the horizontal run. As you can see, the creosote buildup is significant. Long horizontal runs of stovepipe tend to accumulate a large quantity of creosote, due to cooling and condensation of the flue gasses.This installation will need to be swept twice a year, once in the middle of the season and once at the end, in order to keep the creosote down to safe levels and ensure the stove drafts properly.
direct connectsDirect Connect Installation
This is a common, and legal, type of installation for a woodstove or insert known as a direct connect or a positive connection. It involves pushing a short length of pipe up into the masonry chimney flue and closing off the bottom with a metal plate. This type of installation often leads to excessive creosote buildup for two reasons. First, as the hot flue gasses expand from a small six or eight inch stove pipe into the larger masonry flue (usually twelve inches by twelve inches or larger), the gasses cool, condensing and forming creosote deposits. Second, an installation like this is very difficult to sweep, and in order to clean it thoroughly it must be taken completely apart, swept, and reassembled. Often homeowners will not want to go to the extra expense, leading to heavy creosote deposits in and around the direct connect. In this case, those creosote deposits had at some point ignited, melting through the direct connect in several places.Wooden Sun does not do direct connect installations, and when we sweep them we do disassemble them completely. This installation was replaced with a full insulated stainless steel liner all the way to the top of the chimney. A full liner both drafts better and is easier to clean than a direct connect. Read more about the downside of using a direct connect.
slammer“Slammer”
Neither legal nor safe, that does not stop some folks (and unfortunately even some in the business!) from installing inserts into a fireplace without any direct connection, positive, or full liner. This type of installation ALWAYS leads to excessive creosote buildup for the reasons described above, exacerbated by the lack of any type of positive connection to the flue. This lack of positive connection means the flue gasses are floating around in the firebox and smoke chamber for long periods, cooling and bathing the walls in what becomes a thick, tar-like creosote that is extremely difficult to clean. The flue also had ample quantities of third degree creosote. Sometimes the only way to get the thick, tar-like creosote out is to burn it (leave this to the professions!).
inadequate protectionInadequate Hearth Protection
This fireplace was installed by someone who was not familiar with the building code requirements for hearth protection. The hearth was covered by a two-inch-thick slab of bluestone, which looked lovely but did not have the necessary insulating value to protect the wood subfloor. Over time the subfloor and some of the joist beneath burned through.This installation needed to be completely replaced. After rebuilding the subfloor supporting the fireplace, a new fireplace was installed with mineral fiber insulation board underneath the bluestone hearth.
chimney fireMissing Firestops
This is the second story unit in a three-story condominium building. The fireplaces were all installed poorly, and did not meet code. The third-floor unit had, at some point, suffered a chimney fire. Because the firestops that normally separate the floors were missing, chunks of charcoal and debris had fallen and lodged behind the fireplace in the second-story unit. When the debris was removed, it filled a five-gallon bucket twice over.All three apartments needed the fireplaces and chimneys completely replaced. The new fireplaces were installed up to building code standards, including firestops between each floor.
do it yourself installationDo-It-Yourself Installation
At some point, the owner of this house had installed a woodstove into the fireplace. They had pushed some stove pipe up into the chimney and closed off the bottom of the flue with this very thin sheet metal. Creosote had accumulated on the metal and ignited, melting clean through it. In fact, the homeowner had applied a second sheet of the same thin metal, which had then also melted through.We removed the entire installation and reinstalled it with a full insulated steel liner from the top of the chimney to the woodstove.
bird debrisInadequate Chimney Cap
This fireplace contained a woodburning insert that was installed many years ago. There was a chimney cap, but it did not have critter-guard mesh. When we removed the insert, we found that chimney swifts had been nesting in the chimney for some time. The insert was surrounded with debris, including fallen nests, shells, and the skeletons of dozens of baby birds. It was a substantial fire hazard. There was also a nest with five live birds that had to be relocated before we could reline the chimney.We added a chimney cap with proper mesh designed to keep the creatures in the wild and the chimney safe.