Cleveland Home Inspector inspecting black stains caused by candles.
Marko Vovkexplains about Long, narrow, parallel black and gray ceiling or wall stains in buildings or homes can be due to “black stains” or “ghosting” which are soot type dark lines, or black stains appearing in patterns on building ceilings, walls and floors. This colder surface can also be seen with a Flir or a thermal Imaging camera. Thermal tracking or ghosting stains usually occur on cooler surfaces (thermal bridging) such as the locations of ceiling joists, wall studs, or areas of smaller amounts of or completely missing building insulation. Tight energy star homes also are susceptible to black stains if jar candles are being used. Additionally, as air moves through the building, typically up walls and across ceilings, debris in the air, particularly soot such as that left by a burning candle, fireplaces, candles that are scented, back drafting, gas fired appliance, poorly fired gas appliances, garage car exhaust, pellet stoves, and other incomplete combustion conditions which adhere to damp surfaces, cold surfaces, or areas of differential pressure, leaving black stain marks. In a conventionally-framed wood structure, wall and ceiling framing is typically on 16″ or 24″ centers. The wall or ceiling interior surface will be cooler where the framing is located than will be the spaces which are not touched by framing and which, perhaps, are insulated. So if you see black streaks up the building wall in a regular 16″ or 24″ pattern, particularly on cooler exterior walls but potentially anywhere, black stains at carpets or carpet corners, it may be impaction stains, plate-out stains, thermal tracking, or ghosting. Marko Vovk from http://houseinvestigations.com/and from Clevelandmold@aol.com states that 75% of home with these types of stains are usually cause by jar candles or other types of candles. As jar candles burn down, the oxygen gets used up at the bottom of the jar candle. Vovk states that the by-product of pure candle combustion is vapor, CO2 and some other combustion by-products. The carbon dioxide (CO2) is heavy and falls to the bottom of the jar candle causing further incomplete combustion. This results in carbon monoxide generation (CO) and black carbon or soot generation, Additionally, regular candles that are place in draft area, hall areas where people walk, near heat registers, near windows, near fans or anywhere where small drafts exists cause the candle wick to flicker. When the flame flickers it also has incomplete combustion. This soot is very small and can float in a home for weeks and eventually attached to the homes walls, floors, carpets.