How to Detect Mold in Your House with Mold Sniffing Dogs

February 20, 2013 | by Ethan (email) |

Welcome back to our latest Pro-Follow update! If you’re a regular reader, you know that Fred and Kim have hired Joe Bianco to finish their basement, and one aspect of this remodel includes permanently fixing a leak created when the deck was installed. The contractor who built the deck didn’t properly flash (waterproof) it. Fred and Kim eventually discovered wet insulation, discolored wood and a dank smell around one of the windows in the basement. Needless to say, they are concerned about mold, and Fred and Kim want to be sure any mold problem is resolved before concealing everything behind drywall.

To identify any mold problems, Joe has brought in Sam — an expert in mold detection with a proven track record. Sam is a rescue dog from Florida with over 1,000 hours of training, and, along with his counterpart Barney, are two of about 50 dogs trained and certified for mold detection in the country. Sam, Barney and their handler Dave Marcelli comprise Mold Trackers, LLC. Dave and these two dogs provide a very accurate, cost-effective solution for detecting mold. They are based out of the Baltimore area. However, they can respond to mold detection needs nationwide. If you’re concerned about potential mold problems, click that link to get in touch with Dave, Sam and Barney.


Sam is trained to alert (sit) for at least 18 different families of mold, and he can detect mold behind sheetrock, lath and plaster, through plastic and more! Specifically, Sam uses his nose to identify Microbial Volatile Organic Compounds (MVOCs) which are off-gases produced by molds, and his nose is sensitive enough to pick up concentrations as low as a few parts per billion.

I asked Dave if Sam or Barney ever suffer negative effects from smelling mold all day, and he explained that dogs have a unique purging ability to rid themselves of contaminates. Also, Dave is mindful to protect Sam and Barney and maintain their health. Not only does Dave love his dogs, but each dog represents about a $13,000 investment.


Detecting Mold

Dave brought Sam into the basement and walked him around to become familiar with the space. When Dave gave the “seek” command, Sam began sniffing the entire perimeter of the basement looking for mold including the suspicious window. Sam is trained to alert (sit) whenever he finds mold, and that enables Dave to pinpoint an exact location and take a sample. Samples are sometimes sent and analyzed by IMS Laboratory in Michigan.




The average-sized basement only takes about 20 minutes to investigate, and Fred and Kim’s basement was even faster because Sam didn’t find any mold. Dave explained that moisture control is the key to eliminating mold. Since the leak was (temporarily) addressed and mold cannot live off foam insulation, he didn’t expect to find any problems.


I was fascinated by the work Dave performed, and I hope to be back on a job site with him soon. Look for another Pro-Follow with even more mold detection techniques in the near future.

30 Responses
  1. Brady says:

    Very cool. How well can Sam detect mold if it exists at the top of a wall of in ceiling framing given that his nose is a max height of about 4 feet off the ground? How close to his nose does the source of MVOCs (the mold) need to be for him to find or pinpoint the site?

  2. So cool! …. thanks for sharing Ethan. (it’ll be a good resource for me). Fred and Kim’s basement looks like it is coming along nicely as well.

  3. Eek565 says:

    Whoa, that’s really cool. I wonder what the cost difference is between something like this and another form of professional mold detection?

  4. Carol says:

    This is great! I never would have thought a dog could detect mold. Such amazing sniffers 🙂
    Great tip for those of us who have had some water issues in our basement…will have to keep this in mind when we have our issue looked at! thanks, ethan!

  5. Chris says:

    That is awesome. Now I want a dog that can smell mold. Not sure I would really have much of a use for one, but it would still be cool to have.

  6. JustME says:

    Fascinating information Ethan. I’d never heard of dogs helping in this way. I’m glad it doesn’t harm them. I did know they have pretty strong constitutions, but still was glad to hear that these harmful MVOCs didn’t affect them adversely.

  7. MissFixIt says:

    What a great Dog and special talent. Must be a nice to work with your best friend.

  8. Paul&Aundrea says:

    I want that job! Hanging out with your pets always makes for a great day. You think I could train my cats to sniff out anything? LOL I’m thinking that wouldn’t be the best business model for me to pursue. We’re getting ready to move to the VA side of DC, so when we’re house hunting we can keep this in mind. Anyone have any city or neighborhood suggestions (or warnings)?

  9. paintergal says:

    Amazing! Even though they are available nationwide, pretty sure it would be too costly to hire them for a small job halfway across.the country.

  10. debbiedoos says:

    This is a really cool thing. Who would think, makes sense though! I pinned it, and people are digging it.

  11. poiboybf says:

    That’s really cool. I’d be interested in hearing more about the training process for getting a dog to do such a task. Very impressive, mother nature, getting a nose to sensitivities like ppb!

  12. NicF says:

    This is fascinating, reallly neat to see what these dogs are capable of. Also curious as to the cost of an inspection compared to a mold detection company using other equipment.

  13. Mary Sue Paulis says:

    Very interesting! When our basement flooded the restoration company checked the moisture in the walls with an instrument, but I’m not sure they were checking for mold.

  14. trebor says:

    I found this really interesting as well! It’s fascinating what animals can be trained to do. What a great writeup on how the dogs work and even how they aren’t negatively affected by their job…man’s best friend!

  15. HANDYMAN51 says:

    I was worried that this blog’s going to the dogs, but it was a fascinating read! Do they train dogs to find lost keys? 😉

  16. supimeister says:

    no way… i had no idea that dogs could do that… makes sense – very impressive

  17. Reuben says:

    This is cool. I also had no idea people used dogs for this sort of thing. It makes sense though…

  18. Icarus says:

    So does Sam charge by the hour or the job? Does he work for scooby snacks?

  19. mom2kaelyn says:

    That is amazing! I never knew a dog could detect something like that.

  20. mom2kaelyn says:

    I just pinned this for future reference. Never know when one may need it…

  21. bigredmachine says:

    I know this is different, but the house I just bought has a small amont of mold on the back siding. The house is three sides brick and the back is regular siding, what is best way to treat it other than a god powerwashing

    • Is it mold or mildew? What kind of siding? I don’t think I would power wash it. It would just drive the spores around into the cracks. You can use TSP solution and a brush and then hose it off.

  22. katieQ says:

    That’s amazing. I’ve never heard of dogs that can detect mold.

  23. HANDYMAN51 says:

    Saw a ” Mold Testing Kit” at Home Depot for $ 9.95. The dog might have more sensitivity, but a person might want to try the kit first.

  24. That’s incredible!

    Never knew dogs could detect mold!

  25. says:

    I am really thankful to the holder of this site who has shared this enormous paragraph at at this

  26. sheila counard says:

    i need help our home was hit by a cement ruck had to be taken down new home builder walked off job, used wood with black mold on it home has several water leaks we can’t find where they are comng in and we’ve being getting seriuosly sick, feel better when away from home for periods of time thanks you sheila c.

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