"Hi there, I am new to this site but need help with an issue. About a year ago we had our crawlspace encapsulated due to a strong musty smell. The smell went away for about a year but has now returned even stronger. It is now coming through the floor vents of the house located above the crawlspace. The company that encapsulated the space seems to be stumped. They keep telling me they can smell it, but do not know where the smell is coming from. I am super frustrated and want the issue resolved. Our house is on the market and it is unacceptable to have this smell. Does anyone have any idea what to do?"
The encapsulation process is called Clean Space and uses a plastic liner to cover the crawl space area as well as sealing the vents!

Odors are very hard to determine where they are coming from. A musty smell suggests that u have a moisture problem.

Is the area under plastic wet? If so, u will have to find the cause of moisture. Did u get a guarantee from company doing work.

Chuck