Vertical black stripe stains on walls are most likely thermal tracking or ghosting (C) InspectApedia Indoor Wall or Ceiling Ghosting Stains & Building IAQ
Building Air Quality or Unsafe Heating Equipment Indicated by Indoor Stains

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Indoor air quality or unsafe heating systems may be indicated by ceiling or wall stains or ghosting lines:

If the stains in your building are caused by deposits of airborne soot from an oil or gas fired heating system, that system is dangerously unsafe, as this article explains. Fireplaces with poor draft may also result in indoor wall & ceiling stains both uniform near the fireplace or as lines or spots shown at the page top photo.

This article series describes & diagnoses the cause of various interior wall and ceiling stains and explains how to recognize thermal tracking, (also called ghosting or ghosting stains or thermal bridging stains), building air leaks, and building insulation defects. Often these stains are mistaken for toxic indoor mold.

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How to Use Indoor Stains Like Thermal Tracking to Diagnose Building Air Leaks, Insulation Defects, and Indoor Air Quality Problems

Black mold on drywall (C) Daniel Friedman

[Click to enlarge any image]

Significance of Other Indoor Stains and Marks for Building Framing Location or Defects in Heating & Cooling System Operation

Since thermal tracking, or soot marking, or "thermal bridging" always tell us about missing or openings in building insulation or about air leaks, we can learn other facts about a building such as those listed here:

More Indoor Stains Identified as Ghosting or Bridging

A careful examination of the location of indoor stains permits the observer to use thermal tracking or soot marks on building walls or ceilings as an indicator of possible excessive (seasonal) interior moisture or other potential indoor air quality concerns.

Dark stains on building interior walls may appear in other patterns and could be from other causes - we provide photographs, description, diagnosis, and advice for many of these indoor stains in this article series. Let's start with another example of THERMAL TRACKING BRIDGING GHOSTING so that we an distinguish these stains from others listed below.

Reader Question: pictures from our living room.

... these stains are getting worse ... my husband does notice that insulation seems to need work.... Everyone keeps saying it cant be healthy ... I'm worried - K.C. 4/4/2014

Reply: how to recognize thermal tracking or ghosting stains in buildings

Thermal tracking or ghosting stains on building ceilings (C) InspectApedia KC

There is no doubt that we are looking at thermal tracking or "ghosting" - deposits of dust and soot on cooler, more humid areas of ceilings in your home.

These are not themselves a particular health concern but the conditions that cause thermal tracking, if they involve high indoor moisture levels, particularly if that moisture comes from a damp or wet basement or crawl space, could be a subtle clue that there is a hidden mold problem in the building.

Watch out: if the building soot source that is providing material for the black ghosting stains in your photos were an improperly-operating heating system or gas fired appliance dangerous conditions could be present such as carbon monoxide.

In our separate article on recognizing indoor stain types IAQ DIAGNOSIS via THERMAL TRACKING STAINS I discuss all of your photos in more detail.

We explain this phenomenon beginning at the start of this article and we offer some remedies

Safety Warnings about Black Stains Indoors

Sooty barometric damper © Daniel Friedman

Watch out: Ghosting or thermal tracking stains are usually house-dust or soot deposition on walls, ceilings, and perhaps floors.

But if that dust or soot are coming from an abnormal source such as gas-fired heating equipment (or in some cases oil fired heating equipment) the equipment could be unsafe: the same conditions that produce indoor soot from an oil or gas fired appliance can be producing dangerous, potentially fatal carbon monoxide gas.

Oil fired heating equipment does not produce carbon monoxide gas as easily as an improperly functioning gas fired system, and conventional oil fired equipment often runs (normally) producing a little internal soot or "smoke".

But if your oil heating equipment is producing visible soot indoors or if it's making strange and horrible noises, it's probably not working properly, and it too could be unsafe, risking a "puffback" explosion that can blow soot throughout a building and in severe cases can risk a fire.

Sooty gas burner © Daniel Friedman

A gas fired heater normally burns quite clean, but if there is a combustion air problem or a flue gas venting problem the gas fired equipment can very quickly shift to producing soot and / or dangerous carbon monoxide gas (CO).

If you see soot coming out of a gas fired heater you should turn it off and call an expert service technician right away.

See Chimney Inspection Checklist and see COMBUSTION AIR for TIGHT BUILDINGS.

Make sure that your home has working carbon monoxide detectors and smoke detectors installed in the proper locations before moving on to less urgent concerns with indoor stains or thermal tracking.

Harmful indoor mold may also appear as regular stains indoors

Black mold on drywall (C) Daniel Friedman

Usually indoor mold growth patterns depend on the wetting-pattern of building surfaces and modl growth tends to be rather uniform across its area of contamination. But I have found mold growth on a wall stopping at a rather regular horizontal or vertical line that mapped exactly the joint in drywall. A common cause of such regularity in mold growth patterns is mold growth up wet drywall from flooding or from a wet floor; water and dampness originating at floor level rise in the wall but may be interrupted by a drywall joint.

In the photo above you see severe black mold growth on lower drywall along the wall, stopping as water stopped at a drywall joint.



Continue reading at IAQ DIAGNOSIS via THERMAL TRACKING STAINS or select a topic from closely-related articles below, or see our complete INDEX to RELATED ARTICLES below.


Or see WALL THERMAL TRACKING STAINS - diagnosing ghosting stains on walls

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