What’s That Smell in My House?

Reader Contribution by Paula Baker-Laporte

What do you do if you sense that your household air is not up to snuff?

If you suspect that something in your home is making you sick you may need to engage the services of a professional home inspector.  A variety of parameters can be tested, some with simple instrumentation and others only through expensive laboratory procedures. There is no single magic machine that can test your home for every possible problem so doing a little safe detective work before calling an expert will save time and money and help you to reach an accurate diagnosis.

What the Nose Knows

You already own a sublimely sensitive instrument…your nose is a formidable investigative assistant with an astounding long-term memory. Have you ever re-visited a place after many years absence and noted that the familiar distinct smell of the place piques your memory? The unique smell of burning charcoal in Costa Rica, the aroma of fresh ground coffee in Paris, the acrid waft of steel wheels grinding trolley track in a city metro, these are some of the smells locked in my personal olfactory memory. Many people can smell an incredible one part per million or more. This talent, once a crucial survival tool for our hunter gatherer ancestors is now often dulled by the assaults of modern life. But it is a tool that can be cultivated to your advantage. Many, but not all, problems can be detected through their odor. Volatile organic compounds (VOC’s), some molds, some pesticides, dust and gas leaks all have distinct odors.

Using Common Scents

Upon first entering your home bring awareness to what you smell. If there is an offensive odor see if you can trace its source. For your own safety, do not linger there or start your own demolition. If you suspect a problem inside a wall, you could create a larger problem by breaking through the containment. Provide the area with plentiful fresh air until you can get an expert in.

If the first thing you smell is mothballs, potpourri, air fresheners, tobacco or scented laundry products, you may have already discovered the cause of your ill health. These substances contain a constellation of petrochemical toxins that are harmful when inhaled. They should be eliminated and you will be wasting your money if you call a consultant in while these things are present.  The house must then be well-aired and cleaned before any further nasal investigation can occur.

What the Nose Can’t Know

The nose knows a lot, but it does have its limitations as a diagnostic tool. Once you have been in a space for just a few moments you are no longer able to distinguish smells due to a phenomena called “olfactory fatigue”. Your first few whiffs, each time you enter, are all you’ve got. In addition, many serious indoor air quality problems have no odor whatsoever. These include carbon monoxide, radon, some pesticides and some molds.

Even without a serious hidden defect or blatant use of toxins household air becomes polluted through the daily activities of humans breathing, cooking, bathing and washing clothes. In the absence of mechanical ventilation, airing a home out as a part of regular cleaning routine will get rid of stale air and replace it with fresh vital air. The following chart may help you with your detective work.

Common pollutants

Common Causes



VOC’s (Volotile Organic Compounds)

New home, renovation, cleaning products, air deodorizers.

Occupant can smell and trace.

Inspector takes air samples and send to lab for analysis.

Get rid of offending substance,

Dilute with fresh air, HEPA filtration.

Seal sources that can’t be moved.


Water or moisture damage

Moldy or dank smell

Visible flooding or leaks, wet patches appearing on floors, walls or ceilings

Call a mold remediation specialist as soon as moisture or odor is detected

Combustion bi-products

Faulty gas appliances, cigarette smoke, improper ventilation.

Gas Detection Meters. Call your local gas utility if you smell or suspect a problem.

Regular appliance maintenance, quit smoking, buy a CO detector, isolate mechanical room


Leaky or poorly maintained forced air system, poor cleaning.

Visual inspection.

Duct blaster test to determine leakage of ductwork.

Have ductwork professionally cleaned without chemical cleaners,

Buy a Merv 13 filter for your furnace slot and change regularly.

Clean carpeting thoroughly and regularly with a HEPA vacuum. Dust and air your home out regularly


Use of products with pesticides in them. Professional pest application.

Do-it-yourself test kits.

Professional laboratory testing

Learn about Integrated Pest Management and use benign methods for treating pests.


Naturally occurring in some areas

Do-it-yourself test kit

Radon monitor

Hire a professional radon abatement specialist

Lead, Asbestos

Found in older homes in paint and insulation products

Professional home inspection

Do-it-yourself test kits.

Professional abatement, encapsulation

*Although do-it-yourself tests may indicate that a problem is present, consultation with a remediation specialist is often required for accurate diagnosis and safe, effective remediation.

Thank you Jeannie for your question….my first reader response!

Case Study: Jeanne who lives in a small house built in 1918 writes:

“In the spring (primarily), before we open the house for the summer, there is a chemical smell that seems to be coming from the stairs. We don’t smell it on the stairs, exactly. but above them and into the upstairs hallway. 

It doesn’t smell like cleaning solutions, it isn’t mold. (. When we moved in 6 years ago, we sanded the floors throughout the house, but not the stairs or small landings going upstairs)  It smells like a shop chemical. But, we really only smell it when the weather starts to warm.  Any idea on what it might be and how to get rid of it?

Also. with the right nighttime climate in the upstairs bedrooms, we often smell the cigarette smoke from the former owners. Likely from the 60’s and the 70’s. Can we get that out?”

Jeanne has already done some good detective work. She has described the smells that are bothering her and furthermore she has already noted the conditions where and when these smells are most noticeable.

She notes that the chemical smell is most evident when the house has been closed down due to cold weather and this makes sense because smells dissipate when the indoor air is diluted with fresher outdoor air as the weather permits windows to be opened. It seems to be coming from the stairwell and she suspects that it may be from the floors their which had not been sanded and redone with a healthy finish. Air will tend to rise through a house due to stack affect and the stairwell is often the path of least resistance so it might be from the finish on the stairs and it might not. One way to make that determination would be to place a temporary air barrier over this area and see if the smells dissipate. I don’t know where this home is located or if there is a crawl space under it. For all I know Jeanne has never been in her crawl space and one of the many previous owners may have left open containers of chemicals down there! These smells could waft up into the 2nd floor and hang out there drawn by the first opened windows as the weather warms.

As for the second smell she has been able to identify it as stale cigarette smoke. Yuk! But where is it coming from and what is the “right night time climate” when it is most prominent? Perhaps  it smells most when the air is still and humid. Smells are more prominent when there is moisture in the air and, if there is no wind, the good outdoor air that would normally dilute the odor, is not getting in. Most probably, unless this smoker had a very short leash, the whole house will be permeated with smoke particles and so the goal is to get rid of as many of these particles as possible and to keep at it until one day there will be so few enough that they no longer create a bothersome odor.

Here are some of the things Jeannie can do to remove smoke-smell caused by particles that cling to the interior surfaces of her home:

  • Ozonate safely. Remove pets and humans, close up the house and let the ozone run. Open the house, don’t breath, shut off the ozinator, open windows and doors…then go outside and take a deep breath. Enter the house when it has thoroughly aired out and there is no smell of ozone.
  • Wash all hard surfaces with a mild soapy solution and vinegar, several times
  • Remove any soft surfaces that are removable and launder or clean
  • HEPA vacuum all non-removable soft surfaces, crevices etc.
  • Steam clean carpets
  • Try sprinkling baking soda on upholstery, letting it sit for a while and then vacuum
  • Steam clean ductwork
  • Some essential oils like “Thieves Oil” are known to absorb odors (not mask but actually change them).Although I have allergies to many scents….even natural essential oils, I am fine with Thieves Oil. If  Jeannie finds the oil to be well-tolerated and pleasant smelling she can use a diffuser made for essential oils to distribute it into the air.

Has the smoke permeated into the walls and insulation? Under certain conditions odors in the wall can be drawn out of openings in the wall. The next time the smell becomes strong Jeannie can determine this by sniffing one of her outlets. If she discovers that the source of the odor is within the walls then sealing them better is going to help. Replacing outlets with airtight gasketed ones and caulking behind the baseboards would be a very good start on this project.

Good luck Jeannie!

Do you suspect that your home is causing health issues? Are you doing a renovation or new home and have a health question? Please send your questions to info@econest.com and put Mother Earth News Blog in the subject. Your situation will probably be of interest to other readers too so as time permits I will answer your questions in my blog.

Bio: Paula Baker-Laporte FAIA  is an architect, healthy building consultant, instructor for the International Institute of Building Biology and Ecology and author. She is the principle of EcoNest Architecture. She is primary author of “Prescriptions for a Healthy House” and co-author with husband Robert Laporte of “Econest-Creating Sustainable Sanctuaries of Clay, Straw and Timber”.  www.EcoNestHomes.com

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