In recent years, I have investigated numerous com-plaints of black or gray stains in homes. These maybe geometrically shaped stains that outline exteriorwall framing, dots at drywall fasteners, or dirt stain-ing carpeting along outside walls. The stains maycreate a ghost-like outline of the framing (the skele-ton) of the home. Black particles may also occur ontelevision screens, appliances and countertops. Ihave even investigated a home in which stainsappeared on walls, white carpeting under doors anda pure white miniature poodle.

Why does staining occur in our homes? What haschanged to cause these problems?

Dark stains or “ghost stains” are difficult to investi-gate. We need to determine the source of the darkmaterial and its relationship to the pattern of staining.Usually we discover two problems: soot productionand delivery of the soot to the surface. The locationand shape of the stain can give us a few clues. Anddon’t worry—the stains usually are not mold.

Mold?

First, let’s discuss the mold question. With the scarymedia coverage of mold, any black, green or goldmark is a suspected mold growth, but most darkghost stains, carpet stains or deposits on plasticsurfaces are caused by soot or carbon, not mold.

It is possible that some dark stains in the home arerelated to condensation or moisture on surfaces thatmay result in mold or mildew. However, unless thehome shows signs of moisture damage, it is notlikely that stains within the living space are mold-related. Mold and mildew stains are possible ondamp basement walls and wet windows, but moldand mildew typically do not appear as ghost stainson drywall, carpeting or appliances.

Most experts believe you can test a dark stain formold with a bleach-and-water solution. When blot-ted with a 50 percent solution of laundry bleach andwater, a mold stain should quickly disappear orlighten dramatically. If the stain consists of soot orcarbon particles, it will smear and remain dark whenwiped with the solution.

To treat mold, we need to eliminate the moisture,clean the surface, and attempt to remove any foodsource—paper, cellulose, dirt or dust. You can findgood references for mold concerns at websites forthe EPA, the Building Science Corporation, and thestates of Minnesota and Wisconsin. Most of thesetechnical resources recommend solving the moistureproblem and cleaning the surface, so don’t go crazywith mold concerns.

Ghost stains? Soot stains

The dark stains that outline wood framing or drywallfastener heads are often called ghost stainsbecause they appear as ghostly images of the fram-ing or fasteners. Ghost stains may also appear onroom or stairway carpeting, on plastic, around pic-tures or below doors.

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6 Home Tips

Tom Feiza’s Tips For Operating Your Home

HOW TO OPERATE YOUR HOME

SSoooott,, GGhhoossttss aannddUUggllyy SSttaaiinnss

11SSoooott,, GGhhoossttss,, aanndd UUggllyy SSttaaiinnss© Tom Feiza, Mr. Fix-It Inc. This is part of the book “How To Operate Your Home” by Tom Feiza. No part of this document may

be reproduced or transmitted in any form without written permission from the author. For information, visit www.htoyh.com.

Most ghost stains are related to soot or small blackparticles that deposit on surfaces through severalmechanisms. They are difficult to remove becausethey consist of very fine dirt particles or an oilyand/or carbon-based deposit from incomplete com-bustion.

Are stains more common today?

Years ago, when homes were heated with a fire andlit with oil lamps or candles, soot was just accepted.A common chore was cleaning the soot from clearglass lamp mantels. Today we maintain very cleanhomes with many white surfaces, and even a smalldark stain is easy to identify.

Our homes are tighter and leak less air. This is greatfor comfort and energy efficiency, but a tighter homeallows less air exchange with the outdoors to dilutedirt and soot in the air of the home.

We also have forced-air heating systems andnumerous fans and combustion devices that moveair in the home. If systems aren’t perfectlyinstalled—and they are never perfect—air flow willmove particles and deposit stains in remote loca-tions. Many homes can suck air and particles fromthe outside and through carpeting, doors or evenwalls. The carpet becomes a filter that traps dirtand soot.

We love our electronics and plastic. Electronicdevices can create a charge that attracts particles.Plastics may have an electrostatic charge that alsoattracts particles. Many electronic devices move airthrough their framework for cooling—again, movingand depositing particles.

Finally, today we are pickier homeowners. Weexpect our homes to be clean and to stay clean. Wedon’t accept stains in our homes.

Where do the dark particles come from?

There are many possible sources inside and outsideyour home. The exact source can be difficult toidentify, and often you must work from the mostobvious to the remote possibilities. Common sourceof particles are:

• Candles—the big offender. Candles that arescented or in jugs often create more soot thanstandard candles because of incomplete com-bustion. Candles with long, untrimmed wickscan also produce more soot.

• Oil lamps—these create the same problems ascandles. Just look at the glass mantle. Burningincense belongs in this group, too.

• Combustion appliances—any device that burnssolid fuel, oil or gas is a potential source.Incomplete combustion creates particles.Appliances that are not vented properly candeposit products of combustion and particles ina home; a wood-burning fireplace is an obvioussource.

• Gas fireplaces—that nice, lazy yellow flamelooks good but can also produce particles. If thecombustion were more complete, the flamewould be closer to a solid blue color, not a softyellow.

• Gas pilot lights—poor adjustment can producesoot. A pilot light that strikes or “impinges” on asurface may also produce incomplete combus-tion and soot.

HOW TO OPERATE YOUR HOME SSoooott,, GGhhoossttss,, aanndd UUggllyy SSttaaiinnss 22© Tom Feiza, Mr. Fix-It Inc. This is part of the book “How To Operate Your Home” by Tom Feiza. No part of this document may

be reproduced or transmitted in any form without written permission from the author. For information, visit www.htoyh.com.

• Smoking—a possible cause in excessive cases,but often these smoke particles are tan or yellowuntil they pick up common dirt.

• Internal combustion engines—cars, lawnmow-ers, diesel engines. If your home has poor airbalance, these particles can be sucked indoorsfrom the attached garage or from outside.

• Construction-related dirt and dust—drywall-sanding dust or concrete-cutting dust are twosources.

• Deteriorating carpet, drapes and cloth can pro-duce sooty stains.

• Dirt—from soil, pets, kids and animals.

• Cooking—what have you burned lately? Doesyour kitchen fan really exhaust cooking odorsand smoke to the outdoors or just recirculate itinside your home?

• Dust-producing activities—these include wood-working, furniture refinishing, welding, cuttingmetal with flame, and grinding.

• A vacuum cleaner—if your vacuum has a poorfiltering and capture system, it may spread dirtand soot in your home.

Why the ghost-like deposits?

Soot and carbon particles are very small and light.They move easily and can remain suspended in theair for many hours. These particles will also be dis-

tributed by your forced-air heating or cooling systemand most vacuum cleaners.

Several scientific principles describe the action ofparticles depositing on surfaces.

• Changes in air flow When air changes direc-tion, particles can drop out of the air. Where airflows beneath doors, for example, the particlesdrop into the carpet.

• Filtration When air moves through carpeting,the carpet acts as a filter and traps dirt particles.In a home that has an improperly operatingforced-air system, you may see filtration stainsat the exterior baseboard where air is beingsucked into the home. You may see stains oncarpeted stairs since air is sucked through thestairs into the return of the air handler in thebasement.

• Surface temperature changes Air has a cer-tain amount of energy that varies with tempera-ture. At a higher temperature, particles in the airmove quickly; at a lower temperature, particlemovement slows. When air that contains sootparticles moves across a cooler surface, thesoot particles slow and can be deposited on thecooler surface. This action is what causes theghost stains that outline framing and drywall fas-teners; there is less insulation at the wood studs,so the surface is cooler, and the soot depositson the cooler surface.

HOW TO OPERATE YOUR HOME SSoooott,, GGhhoossttss,, aanndd UUggllyy SSttaaiinnss 33© Tom Feiza, Mr. Fix-It Inc. This is part of the book “How To Operate Your Home” by Tom Feiza. No part of this document may

be reproduced or transmitted in any form without written permission from the author. For information, visit www.htoyh.com.

• Increased air flow Warmer air rises, andforced-air systems push, pull and move air. Theair flow can cause visible deposits on and aboveheating grills, above radiation equipment, andabove light bulbs adjacent to walls. Some of thedeposits are also caused by the convective flowof dirty air in the room.

• Electrostatic charge Electronic air filters andsmoke filters use electrostatic charges to filterair. The same electronic-charge principles attractparticles to the TV screen, some plastics, elec-tronic equipment and appliances. Movement ofair through the ductwork in your home can alsocharge particles in the air and make them stickto surfaces.

HOW TO OPERATE YOUR HOME SSoooott,, GGhhoossttss,, aanndd UUggllyy SSttaaiinnss 44© Tom Feiza, Mr. Fix-It Inc. This is part of the book “How To Operate Your Home” by Tom Feiza. No part of this document may

be reproduced or transmitted in any form without written permission from the author. For information, visit www.htoyh.com.

• Gravity Eventually, particles and debris will dropout of the air. They often create deposits on flatsurfaces such as countertops.

What can a homeowner do?

Start by understanding the sources of soot and dirtparticles. Consider the process that may be deposit-ing the soot on surfaces in your home. Then elimi-nate the obvious sources and watch for futurestains. Be particularly wary of scented candles, can-dles in jugs, oil lamps and gas fireplaces.

If you must use candles, use high quality candlesand burn them in an open area – not in a partiallyclosed container. Keep the candlewick trimmed to _inch or less for better combustion and a cleanerburn with less soot.

Have all your combustion appliances serviced byprofessionals on a routine basis—a good practicewith or without soot problems. Specifically ask thecontractor to check the combustion gas venting andtest for backdrafting of combustion gas. Whenbackdrafting occurs, signs of it may be visible atvent connections. If the contractor can’t knowledge-ably discuss venting, air balance and backdrafting,look for a contractor with more experience.

Unfortunately, there are few resources and a limitednumber of experienced consultants who understand

the soot and ghost stain problem. If your home hasa particularly bad problem, with strange depositsoutlining walls or strange patterns in carpeting, it’sprobably due to an air imbalance in your home com-bined with a soot production problem. This type ofair flow problem could be investigated by a consult-ant who specializes in home performance and hastraining in measuring air flow and pressure differen-tials. Your home should be evaluated as a compli-cated set of interrelated systems moving air andcreating differential pressures.

HOW TO OPERATE YOUR HOME SSoooott,, GGhhoossttss,, aanndd UUggllyy SSttaaiinnss 55© Tom Feiza, Mr. Fix-It Inc. This is part of the book “How To Operate Your Home” by Tom Feiza. No part of this document may

be reproduced or transmitted in any form without written permission from the author. For information, visit www.htoyh.com.

It appears that most ghosting problems are notdirectly related to construction. Problems are oftenrelated to increased production of soot, more light-colored surfaces in our homes, and higher expecta-tions of homeowners. Increased use of candles cer-tainly has had a big impact on increasing the sootand ghosting stain problem.

HOW TO OPERATE YOUR HOME SSoooott,, GGhhoossttss,, aanndd UUggllyy SSttaaiinnss 66

HOME TIPS Written by Tom FeizaThe book is available at

www.amazon.com or through Tom at: www.howtooperateyourhome.com

or www.htoyh.com 262-786-7878.

See Tom’s book How To Operate Your Home(ISBN 0-9674759-3-7) for great information on “operating” a home.

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© Tom Feiza, Mr. Fix-It Inc. This is part of the book “How To Operate Your Home” by Tom Feiza. No part of this document maybe reproduced or transmitted in any form without written permission from the author. For information, visit www.htoyh.com.