Trask Research, Inc. - Mold Problem Solving

Mold Remediation on Floor Joists

By: Rob Stark, Sr. Mold Remediation Specialist

CONTAIN - the mold from spreading into uncontaminated areas;

KILL - the mold;

REMOVE - the dead mold and materials used for remediation; and

PROTECT - the cleaned out area against future mold infestations.

Basements an d c rawl spaces are one of the top 3 areas that have mol d c ontamination on floor joists. This is generally due to the lack of a dehumidifier or from flooding, water damage, or a leak. Allowed to go undetected or ignore d c an cause up to a total loss of a home or office, an d c reates a health hazard for families and employees.

You may also want to refer to mold remediation of basements and crawl spaces for further information on removal of mold from floor joists.

Before entering an area infested with mold, be sure to have the proper protective equipment: P100 respirator, gloves, goggles and protective clothing (Tyvek suit or at least long pants, and long sleeves with a hood. Always keep your exposure to mold and mold spores to a minimum.

1.) Locate and fix all sources of mold-causing water intrusion such as water damage/flooding, recurring flooding, plumbing leaks, poor drainage, blocked air-conditioning condensation drain lines, high humidity in your basement/crawl space, and high indoor humidity [e.g., above 50%]. The infested joists need to be dried out in their entirety, and the moisture that caused the mold growth needs to be eliminated as soon as possible or mold will begin growing again.

2.) Inspect and test for mold indoors. Outside testing should be done as a baseline. Find and locate all toxic mold infestations (visible and hidden) in the entire home or building by thorough, all-around mold inspection and mold testing (with mold laboratory analysis and mold species identification of collected mold samples).

° Conduct a mold control test using a do-it-yourself mold test kit outside your home or building with the test kit being at least five feet out from any roof or porch overhang. You need this outdoor control test for comparison of results from your indoor mold testing as a baseline to your indoor tests.

3.) Test the outward airflow from each heating/cooling duct register for elevated levels of airborne mold spores. If there is a serious toxic mold infestation anywhere in a building, airborne mold spores from such mold locations will usually enter an d c ontaminate the heating/cooling equipment and ducts, as well as the rest of the building. Use our EZ Mold Test Kits to collect possible mold spores in the outward air flow from each register with the system running on fan ventilation.

4.) If any residents or workers are experiencing any possible toxic mold health symptoms, or if there is a strong smell of mold, or if there are visible signs of major mold growth anywhere in the basement, or if the basement tests positive for elevated levels of airborne mold spores, the occupants should move temporarily to a mold-safe place until after successful mold remediation an d c learance testing.

5.) Occupants moving out should not take any clothing, personal possessions, furnishings, furniture, or equipment until after such items have been effectively mold decontaminated outdoors [or in a clean room built from plastic sheeting] to avoid mol d c ross contamination of the temporary living or working quarters.

6.) Do not paint over mold problems. Mold uses paint as food. Don’t expect to kill mold successfully by using paint containing a mildicide [it is too weak to kill existing toxic mold infestation] or with a paint primer sold to hide water damage stains. Do not rely on Kilz to kill mold; it’s not a fungicide, does not kill mold, and is NOT EPA-registered. However, Kilz is an excellent product to hide or camouflage defects like water damage stains prior to painting over problem areas.

7.) Before beginning to work in the mold-afflicted areas, contain the moldy work area (and thus contain the toxic mold spores that will be released into the air by opening up mold-contaminated areas) by using wall-to-wall, floor-to-ceiling plastic sheeting as containment walls. Use 6 mill thick, clear plastic sheeting that you can buy at a hardware store or home improvement center.

8.) While working inside the mol d c ontainment area, always wear effective protective gear. All of the following items are available on our web site:

Tyvek protective coveralls, or long sleeve shirt and pants.
Gloves: either disposable latex, Nitrile or good work gloves. Avoid touching mold or moldy items with your bare hands," recommends the U.S. Environmental Protection Agency.
Avoid breathing in mold or mold spores. Wear a P100 respirator mask using organic vapor cartridge filtration.
Wear goggles. Wear eye goggles with no holes if you are not wearing the P100 one piece, full face breathing respirator. "Goggles that do not have ventilation holes are recommended. Avoid getting mold or mold spores in your eyes," advises the U.S. Environmental Protection Agency.
Pump spray or fog the areas that have visible mold growth with Oxy Mold MX-501™ two times letting it naturally dry in-between sprayings.

9.) Do not use chlorine bleach [sodium hypochlorite] to kill mold or disinfect moldy areas. Bleach is not an effective or lasting killer of toxic mold growth and mold spores on and inside porous, cellulose building materials such as wood timbers, drywall, plasterboard, particleboard, plywood, plywood substitutes, ceiling tiles, an d c arpeting/padding. Read the Forest Products Research Study on Why Bleach Does Not Kill Mold. Bleach also destroys the wood that holds your home together.

10.) After the killing of all visible surface mold, the next step is to remove and to clean off as much surface mold growth, mold stains, and mold odors as possible. "Dead mold may still cause allergic reactions in some people, so it is not enough to simply kill the mold, it must also be removed," recommends the U.S. Environmental Protection Agency. Persons cleaning mold should be free of mold symptoms and allergies. Gloves should be worn during cleaning. A good first step is to use a HEPA vacuum cleaner to remove loose [invisible to the eye] airborne mold spores and mold growths deposited on all surfaces such as ceilings, walls, floors, and upholstered furniture. Vacuum at least twice; go in a different movement direction each time you do the vacuuming; horizontally the first time and vertically the second time.

11.) Except for wood support timbers (studs, rafters, floor joists) and building materials to be saved, remove and safely discard all other mold-contaminated building materials (such as particle board, drywall, plaster, plasterboard, ceiling tiles, paper-backed insulation, mold-laden insulation, plywood, plywood substitutes, an d c arpeting/padding) in doubled up construction trash bags (double bagging) with a 6 mil thickness.

12.) Remove all mold growth from the mold-infested wood surfaces an d c ontaminated insulation. All wood beams, wall timbers, floor joists, plywood surfaces, and other lumber to be saved need to be totally cleaned of mold growth by using power tools such as a planer, grinder with wire brush attachment, and sander, or replace the moldy timbers. Mol d c annot eat polystyrene insulating board such as green board but mol d c an grow on organic dust which lands on the insulating board and insulation.

13.) Re-spray the cleaned out area twice with an EPA registered mold killing fungicide.

14.) Mold has strong pigments and actually stains wood materials like floor joists and wall studs. If you want to remove the stains you will have to either sand or wire brush the stains out of the wood. HEPA vacuuming is another solution to this, and can greatly aid the cleaning process after sanding or brushing. Regular vacuums are unable to remove microscopic particles like mold spores.

16.) After the mold remediation is completed, mold test (clearance testing) all of the remediated surfaces plus the air of each room in the area, and the outward air flow from each heating/cooling duct register to find out if those areas are now mold safe prior to rebuilding the cleaned out areas with new building materials.

Provided that all moisture problems have been fixed and the area is dry and well ventilated, mold should not be able to start growing again.