Musty Odors           Odors are red flags that something is wrong. Musty odors mean there is either a mold or moisture problem that has caused bacteria and possibly mold and other microorganisms to flourish. Often this is from a plumbing leak, excess moisture in the crawlspace, or water that has penetrated into the walls or ceiling. The problem may be new or old. It may be simply an odor at the present time but grow into something bigger if there is an active water problem not taken care of.           An odor may persist long after things have dried out. A pair of well-worn socks may still smell from bacteria after they seem to be dry. Humidity plays a factor. Odors increase with increasing levels of humidity.           Nuisance or Health Threat?           Some of the chemicals produced by mold include acetone, ethanol, hexane, and isopropanol1. These are irritants and can affect the central nervous system causing headache, attention deficit, inability to concentrate, dizziness, respiratory problems, allergies and asthma.           Mold is not the only organism that produces musty odors.  All sorts of microorganisms produce chemicals as part of their normal metabolic processes that cause odors, including bacteria and soil microorganisms. Like many hazards, the dose may determine the poison. Is the odor overwhelming or is it barely noticeable and only after the building has been closed up for some time? Either way, you don’t have to live with an odor problem. It is a nuisance and your body’s way of telling you that something is wrong that needs to be corrected.           Where Odors Come From           The first thing to consider if there is a musty odor is that there is the potential for mold growth. You should have a mold inspection done that includes the crawlspace and basement. If mold growth is not found it may be hidden. Consider testing for mold and having the walls checked in places with obvious sources of moisture such as bathrooms and kitchens.           Sources of Musty Odors           Crawlspaces. Odors may peculate up through cracks in flooring Wall cavities. The odor may find it’s way through the electrical outlet in to the room Painted block walls in basements. Mold grows behind paint on damp walls Sewer gas. Water damaged carpet Under kitchen sinks Air conditioning and heating duct work Swamp coolers           Rule out the potential for odors that can come from sewer gas. If a sink, shower or bathtub has not been used in a long time, the pluming trap might have dried out allowing sewer gas to come out. This can be avoided by turning on the water periodically. Sewer gas can also enter a home when the pluming vents are clogged with leaves on the roof or the septic tank is full.           A simple way to tell if the odor is coming from a wall cavity is to sniff an electrical outlet. Electrical outlets are basically holes in the wall. If there is an odor coming from the outlet you may want to consider having the wall tested for mold. Sometimes mold is not detected but there is still an odor. The odor may be coming from spaces that simply have a musty, earthy smell from soil or because they were wet at one time even though they are now dry.           Eliminating Odors           Crawlspaces may produce an odor, even when they appear to be dry and well-ventilated. For permanent solutions for remediating odors caused by crawlspace please go to the chapter Crawlspaces and Basements in the first section of this book that deals with mold. If there is a musty odor under the kitchen or bathroom sink and you have a crawlspace there is a chance the odor is coming up from the crawlspace. The odor can permeate up around gaps around the plumbing and water supply pipes. When the house was built, holes were cut into the walls behind the cabinet and into the floor for plumbing. These holes are drilled slightly larger than the pipes and air can pass around them.           To reduce odors, seal around the pipes and plumbing. It may be helpful to use a spray can of insulating foam. Seal around the plumbing inside the cabinet then go into the crawlspace (put on protective equipment), locate the plumbing under the floor and seal it there. If you don’t have a crawlspace the odor may still be coming from around plumbing. There is often a hole left in the concrete slab where the plumbing goes into ground. The soil around it may be causing the odor. If sealing around the plumbing does not do the trick, the cabinet may need to come out to investigate further.           The ultimate way to remediate odors coming from walls that do not have mold growth is to treat the wall as if mold were present and remove and rebuild it. You may consider just containing the odor. This can be done by taking the cover plate off the outlet and sealing around the wiring inside the box with foam. Do not attempt to do this yourself. Hire a licensed electrician. The simplest and immediate way to get relief if you notice the odor is coming from an outlet is to cover the outlet with tape.           Often in commercial buildings the odor is coming from the air conditioning or heating system. There may not be any mold spores associated with the odor. The odor is present because the wall or ceiling cavities are being used as duct work. The system is pulling air from the walls or ceilings. Walls and ceiling leak or may just have an “old house smell”. You don’t know where the air being supplied is actually coming from. The best way to remediate this is to install duct work that connects the return vent to the air handler instead of using the wall or ceiling spaces.               Back to top                            Copyright © 2014-2017 Healthy Living Spaces LLC.  All rights reserved.   877-992-9904 Revised: July 05, 2017. Information in this document is subject to change without notice. Other products and companies referred to herein are trademarks or registered trademarks of their respective companies or trademark holders.