Just bought a 25 year old home that has improperly installed insulation in the crawlspace. The insulation is fiberglass rolls with a paper backing, and is installed with the paper facing down, toward the ground. When the home inspector and I explored the crawlspace, we could see green mold growing on the joists where we pulled the vapor barrier aside to peek up into the cavity.
The source of moisture seems to be a concrete pad that butts against the foundation and collects water from the shed that sits atop it. I plan to remove that shed and the concrete pad before doing work with the insulation.
I intend to replace the insulation with either the same type or a plastic vapor barrier cut to fit between the joists and un-faced insulation instead. The new insulation will be installed with the vapor barrier facing the living space.
My question is about the mold: once the old insulation is pulled out of the crawlspace, how should the joists and flooring be cleaned to inhibit further mold development? Is there a recommended time period to leave the joists exposed to dry? I will be doing this in the Fall when we are likely to have dry weather, and outside temps will be closer to inside.