Photograph of  thermal tracking or soot tracking - cool surface, moisture condenses, soot is deposited - Daniel Friedman 02-12-16How to Recognize & Diagnose Occupant Stains & Smudges on Building Walls

  • STAINS HUMAN OCCUPANT - CONTENTS: How to Recognize & Diagnose Human Occupant Stains and Smudges on Building Interior Walls. How to Recognize Wall Stains made by people. Cigarette, Cigar or Pipe Smoker Stains in Buildings. A photo-guide to common indoor ceiling and wall stains caused by human occupancy in buildings
  • POST a QUESTION or READ FAQs about identifying building stains traced to people and occupancy

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Dark indoor stain diagnosis: human or pet occupants: this article describes & diagnoses the cause of various how to recognize (and clean or prevent) stains and smudges on interior walls when these marks are caused by human occupants.

Examples of human-caused indoor stains include soiling from a person's head leaning against a light-colored wall or brown stains due to cigarette smolking. When investigating a building for a mold problem, you can save mold test costs by learning how to recognize stains that are basically harmless.

Don't waste money testing these stains. These are indoor marks and substances that you can easily learn to recognize.

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How to Recognize Wall Stains from Human Occupants

Photograph of dirt from a pet smudging a wall

Save your mold test money, and increase the accuracy of your mold contamination inspection or test for toxic or allergenic mold in buildings: review these items to learn recognize non-fungal materials or even possibly harmless cosmetic "black mold" often mistaken for "toxic fungal growth."

Black marks on interior walls such as painted drywall might be also be dark wall stains where people rested their heads in bed (as shown in this photo at left).

Look at the location of these stains and imagine a bed having been placed with its head against the wall shown in the photograph. Notice the two wall lights.

This is where a bed was almost certainly placed, and we can easily explain these black stains on the drywall. No further testing would be appropriate in normal circumstances.

We welcome more thermal tracking, soot tracking, air bypass leaks, and similar photos of indoor stains as well as text suggestions to expand this detail and would be glad to credit contributors.

Usually soot marks, thermal bridging, or thermal tracking stains appear, if at all, in the building interior locations discussed in the remaining sections of this article.

Cigarette, Cigar or Pipe Smoker Stains in Buildings

Stains run down wall (C) D FriedmanWe have inspected a number of buildings inside which we observed brown nicotine/smoke stain patterns traced to smokers.

First, brown-colored stains that appear either uniformly or in thermal-tracking streaks on walls and ceilings.

Often these cigarette smoke stains are found principally in one or two rooms of a home occupied by smokers - rooms where, obviously, people spent more time smoking such as in a living room around a couch or recliner chair, or in bedrooms.

Watch out: smoking in bed is a well-known fatal fire hazard

In these homes, the observation that brown stains are found in just these occupied spaces is an argument against other causes that would produce more uniform staining, such as heating system problems or poor building wall or ceiling insulation.

Wall stains (C) D Friedman

Our wall stain photos above and at left illustrate a second instance, we find brown stains that appear to run in rivulets down building walls. This is essentially the same cause, and these stains will appear most severe in the same locations we described above.

The difference is that there have also been occasions of very high indoor moisture or even wet conditions in the "brown rivulet streak stain" homes.

Moisture that condenses at high levels on a building wall will eventually produce droplets that run down the wall.

The dissolved nicotine and tobacco smoke stains are concentrated and redistributed by these moisture drip marks. Or conversely, we may see a tan-stained wall with clean rivulet areas where water droplets have carried stain material away.

Even when the interior wall has later been cleaned of smoke tar and nicotine marks, we may find remains of that material behind baseboard trim.

Watch out: any soiling on building walls can leave rivulet-pattern stains if the wall has been wet for any reason.

Mottled Pattern Indoor Smoker Stains

Mottled indoor wall stains (C) D FriedmanSometimes, depending on the water deposition pattern on building walls, these smoker stains may appear mottled in pattern rather than streaked.

Watch out: Mottled wall or ceiling stains may also appear not from smoking indoors but from building leaks that dissolve brown ingredients in wall, ceiling or floor cavity framing or insulating materials.

We've also found this condition in a room where someone attempted to wash a cigarette or cigar smoke stained ceiling or wall, using insufficient water or cleaner or other poor methods.

At HEAT LOSS INDICATORS we also discuss and describe brown stains found on building ceilings and walls that are traced to smokers.

That is, areas in buildings where people have spent time smoking cigarettes, pipes, or cigars.


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