Dear Helpdesk

I live in Kamuela, HI at an elevation of 3000 ft. It is often chilly and damp here. My house is up on post and pier 2-4 ft above ground. In Dec. and Jan. the floor gets very cold at night so I decided to put R-19 under the floor (oak flooring with 3 coats urethane varnish). After spending 4 days crrawling under my house and stapling the insulation between the floor joists, I got into an area where the light is better and I could see green mold and dark grey mold on the bottom of the flooring. I fear I have put about 800 sq. ft of insulation over mold without realizing it. Is it necessary for me now to go back and remove all the insulation and treat for the mold or will it die if I cover the insulation with Tyvek? I hope I don't have to re-do all this work because it was a horrible job to start with.
Also I was planning to skirt the bottom of the house with 1/4" Hardypanel to block off the chilly damp wind that blows under my house at night.
Thanks for your advice.

I am not sure about it, and not sure anybody else here can give a good answer. Maybe we can kick it around and figure out something. Some well understood problems have a single, definite answer. This isn't one of them.

Mold is nasty stuff. It is possible if you left the vapor barrier on the bottom, the mold may not get enough moisture to live. On the other hand, you may have made a cozy place for it to thrive. Twvek does not stop moisture, but it can keep moist air from infiltrating. Hardypanels is not a brand I am familiar with. However, once again, stopping cold damp air, has to help. You might check the mold in a month and see if it looks worse.