Odors in Encapsulated Crawl Spaces

By July 13, 2017 August 23rd, 2017 No Comments
Odors in Encapsulated Crawl Spaces: 
ATMOX to the RescueLately we have received numerous phone calls and emails from homeowners frustrated and looking for help.  They have encapsulated their crawlspace and now they have terrible odors wafting up into the house.  These homeowners have generally spent thousands of dollars to fix some type of crawlspace issue only to create a new one.The description of the odor varies somewhat, but it is often described as smelling like cat urine – yes, very unpleasant.  It isn’t easy to measure a “smell” and so many of their contractors are denying the issues or at a loss of what to do next.  Some people are also much more sensitive than others with complaints ranging from annoyance to migraine headaches.
What is causing the odor?

It could be one of several things.  You will get different theories on this, and it is likely a combination of several.  Here are the most likely culprits:

  • Soil Gas: The soil underneath the plastic is releasing gases.  These gases and smells are permeating through the plastic liner.
  • Plastic Liner:  There can be chemical off-gassing from plastic and other household items.  There is a lot of finger pointing here related to whether this is primarily in certain liners.
How to address the odor?

  • Use ventilation to get the odor out of the crawlspace.  It is really very simple, the trapped gases and odor have to be dispelled to the outside to avoid them being trapped in the crawlspace.
  • Create an ATMOX System setup for a closed crawlspace. For an encapsulated system with dehumidifier, add a FLEX or SMART Controller to control fresh outside air at the right times and control the dehumidifier as needed.  Depending on the size of the crawlspace only a few vent openings will need to be reopened or created.  The ATMOX Multi-Mount Fan can even be used with louvers to keep the crawlspace completely closed when fans aren’t running.



What are the benefits of ATMOX to the homeowner?

  • ATMOX ventilates out the smell and the air is fresher. Homeowners of ATMOX systems in closed or open crawlspaces tell us how much fresher the air seems in their homes.
  • Fresh air will improve overall air quality. Contrary to what encapsulation companies preach – you can’t improve air quality by trapping it.  There is a reason why overly tight homes are now in need of ERV systems (Energy Recovery Ventilators) for living spaces – the air is stale and may be full of pollutants.  There is a common phrase used in green building construction – Seal tight and ventilate right!
  • Reduced use of dehumidifier will lower energy consumption as an ATMOX system uses a fraction of the power.

Contact ATMOX for assistance on a Closed Space Odor Problem.

Last Spring 2016 Class:

Join us in Greenville/Spartanburg, SC.  Registration is required.  Learn more about details on the ATMOX website.

May 18, 2016 – Greenville, SC
Hampton Inn – Spartanburg, SC

Additional 2016 Classes to be scheduled and posted soon.

Contact ATMOX
Phone: 704-248-2858     Email:


If you need a Home Inspection please Call us for a Free Quote 24/7 at 727-224-0837 and Remember we service the following areas

Hudson Home Inspection, West chase Home Inspection, Tampa Home Inspection, St. Petersburg Home Inspection, Palm Harbor Home Inspection, Tarpon Springs Home Inspection,  Safety Harbor Home Inspection, Clearwater Home Inspection

Mike Potts

Mike Potts

After graduating from Michigan State University with a degree in structural engineering, Mike moved to Tampa Bay and soon discovered a need in the community for trained, professional inspectors. Using his training in the field, Mike established Affordable Inspections, Inc. in 1992 and began offering his services to the public – inspecting commercial and residential properties. Taking on not just inspections, but full-on construction projects, Mike made a name for himself as an expert in structural engineering and worked on large commercial buildings in Tampa Bay and Clearwater.