To protect remediators and residents from exposure during mold removal and to ensure that mold spores won’t be spread a strategy for mold containment is necessary.
A heavy infestation of black mold in a limited area could have the potential hazard of spreading more spores than mold covering larger area so the strategy for containment may be judgment call but we suggest referring to our Guidelines for Mold Remediation.
Full Mold Containment
Professional remediators should isolate the area using plastic sheeting (treated with flame retardant). This should include any doors or air vents within the containment area. Professional remediators set up a negative pressure mold containment area to make sure spore contaminated air does not spread from room to room. This is accomplished by pushing the air with an exhaust fan through a duct to the outside. There are HEPA-filtered units for this that are the safest and most proficient solution.
An airlock or decontamination room need s to be made of tape and plastic sheeting immediately outside cleanup area. Remediators are to use this space to change into their protective suits, (including booties, gloves and respirators). The airlock should also house plastic waste bags that need to be completely sealed and wiped down with a damp rag before removal.
As an additional precaution, you may wish to hang plastic sheets over doorways between the containment area and other rooms in the house. It also makes sense to remove area rugs, particularly where workers will be walking back and forth, and to tape nonslip protective coverings over these paths. Smoke testing may be used to ascertain whether air is flowing from the containment area into other rooms.
In order to provide proper containment, air must be continuously blown out of the contained work area (and provisions made for air from the rest of the building to infiltrate the work area). Unless the exhausted air is HEPA-filtered, mold spores may move with wind into indoor environments close by.
Keep in mind that most moldy construction materials are considered rubbish, and there are no requirements for secured disposal, as there are for lead paint and asbestos. Of course, everything that gets thrown out is eventually attacked by microorganisms but that doesn’t mean you shouldn’t be cautious in the interest of protecting your neighbors. Tossing moldy materials into an unprotected dumpster can aerosolize contaminants. Moldy materials should therefore be sealed in heavy-duty plastic bags before removal from the containment area and disposal.
The EPA has additional information on Mold Containment and Personal Protective Equipment.
Mold Containment for Smaller Jobs
While it isn’t always possible for homeowners to create the containment conditions that professional remediators create, it’s important to to isolate the work area as much as possible. Enclose the mold containment area with polyethylene sheeting. For the entrance, tack or tape two pieces of plastic sheeting to the top of the wood trim over entrances to the room to cover any open doorways. Each piece should cover approximately two-thirds of the opening.
Attach one piece to the top and right side of the doorway, and the other piece to the top and left side of the doorway. The section in the middle where the two pieces overlap will function as a partial air seal while also allowing you to enter and exit.
Alternatively, you can create a “booth” around your work area by arranging four spring-loaded rods vertically between the floor and ceiling and attaching horizontal pipes to the rods with hose clamps or duct tape. Then you can tape plastic sheets to the pipes to enclose the space. Again, leave an overlap between two of the pieces of plastic so you can enter and exit. In designing any kind of containment-like conditions, be sure that one wall of the isolated area has a window to the exterior, so a box fan can be used on exhaust. This will remove many of the spores that may become aerosolized when the mold is disturbed.
In most cases, after the mold growth has been eliminated, and with the fan still operating on exhaust, other room surfaces can be cleaned with a HEPA (high-efficiency particulate arrestance) vacuum to eliminate contaminated dust; nonporous surfaces can be damp-wiped and allowed to dry.