Black mold removal in Blair, WI for growth that has taken hold

What people mean by black mold

The phrase usually refers to Stachybotrys chartarum, a greenish black mold that grows on materials high in cellulose, such as the paper facing on drywall, ceiling tiles and wood products, when they stay wet for a long time. In everyday use, though, homeowners call almost any dark growth black mold. Several other common genera also appear dark. The CDC notes that the color of a mold does not tell you how hazardous it is, and that any visible growth indoors should be removed regardless of species. We follow that guidance in Blair, WI homes: the removal method depends on how much growth there is and what it is growing on, not on its shade.

What dark growth does tell us is something about its history. Stachybotrys generally needs sustained moisture to develop, so heavy dark colonies often point to a leak that has been active for weeks or longer, a past water loss that was never fully dried, or chronic condensation. That is why every black mold job begins with finding the water.

Why heavy growth needs a sealed work area

Disturbing established colonies releases spores and fragments into the air. Tearing out a moldy wall in an open room can move that material into bedrooms, closets and the HVAC system. Before removal begins, our technicians build a containment of polyethylene sheeting around the work zone, seal supply and return vents, and set up negative air machines that exhaust filtered air. Workers wear respirators and disposable coveralls, and materials are bagged inside the enclosure before they are carried out.

The EPA guidance on mold in homes suggests that growth covering more than about ten square feet calls for professional work, and that people with respiratory conditions or weakened immune systems should not do cleanup themselves. Heavy dark growth frequently exceeds that size once the wall cavity is opened, because what shows on the surface is often a fraction of what is behind it.

Removing growth from different materials

Drywall and insulation with growth are cut out past the visible edge and discarded, since mold roots into their porous structure. Framing lumber is usually salvageable: surface growth is removed by HEPA vacuuming, sanding or wire brushing, then the wood is damp wiped. Concrete and metal are cleaned in place. Where wood has lost strength from long term moisture, the affected member is replaced rather than cleaned.

Covering growth with paint or sealant is not removal. Encapsulating products have a role after cleaning, but applied over live growth they only hide the problem.

Closing the job properly

Before the containment is taken down, the work area is HEPA vacuumed and wiped, and moisture readings in the remaining framing must be normal. You may choose independent verification, described on our Mold Testing Inspection page. Rebuilding follows, with new insulation and board installed by our Drywall Repair crew once the cavity is dry and clean.