Can mold and efflorescence ever look similar enough to be confused?
Thanks
Absolutely! There are several of on this board that have been tricked up by it coming up from crawlspaces. Sample it and send it to the lab for confirmation. I have been thrown off by wet termite treatment crystalizing and having it look like mold too. Don’t assume anything in this job or else it might come back to bite you in the end. Sample and send out for analysis if you are unsure. If the client doesn’t want to pay for the lab fees, they are cheap enough that the little bit of expense out of your own pocket can save a lot of money for paying for a claim later on down the line.
Usually efflorescence is water soluble and fungus is not. As Scott mentioned, the safest way to differentiate between the two is the test.