Fix the water first
Mold removal without fixing the moisture source is a temporary fix. Before or during remediation, the source must be corrected: a plumbing leak repaired, a roof or window leak sealed, a crawlspace vapor barrier installed, bathroom ventilation improved, drainage corrected or humidity reduced.
What gets removed and what gets cleaned
- Porous materials with mold growth, such as drywall, ceiling tiles, insulation, carpet and pad, usually need to be removed and discarded, because mold can grow into them and they can't be reliably cleaned.
- Semi-porous materials such as wood framing can often be cleaned, sanded or treated, depending on the extent of growth, and then dried.
- Non-porous materials such as metal, glass and hard plastic can usually be cleaned.
The goal of remediation is to physically remove mold, not just kill it. Dead mold can still cause reactions in sensitive people. Painting over mold doesn't fix it.
The remediation process
1. Assessment and planning based on the inspection. 2. Containment of the work area, with negative air and HEPA filtration as needed. 3. Removal of affected porous materials, bagged inside containment. 4. Cleaning of remaining surfaces, including HEPA vacuuming and wiping with appropriate cleaners. 5. Drying of the structure, with moisture readings to confirm materials are back to normal levels. 6. Post-remediation check: visual inspection, moisture readings, and in some cases clearance testing by an independent inspector. 7. Rebuilding with new drywall, insulation and finishes once the area is dry and clean.
Chemicals and coatings
Some contractors apply antimicrobial products or coatings after cleaning. These can have a role, but they aren't a substitute for removing mold and fixing moisture. Ask what product will be used, why, and how it's applied, especially if anyone in the household is sensitive to chemicals.
Preventing regrowth
- Keep indoor humidity moderate. Many guidelines suggest keeping it below about 50 to 60 percent.
- Use bathroom and kitchen exhaust fans that vent outdoors.
- Fix leaks promptly and dry wet materials within a day or two.
- Keep gutters clean and grade soil away from the foundation.
- Insulate cold surfaces where condensation forms, such as pipes and exterior walls.
- Ventilate or condition crawlspaces and basements properly.
Questions to ask
- What moisture source will be fixed, and who will fix it?
- What materials will you remove, and what will you clean?
- How will you confirm the work is complete?
- Do you recommend independent clearance testing?
- Who handles rebuilding, and is it included?
How long remediation takes
A small, contained job may take a day or two. Larger projects involving several rooms, wall cavities, crawlspaces or HVAC systems can take longer, plus drying time and rebuilding. Ask for a schedule that separates remediation from reconstruction, so you know when each room will be usable.
Belongings
Hard items such as metal, glass and hard plastic can usually be cleaned. Clothing and fabrics can often be laundered. Porous items such as upholstered furniture, mattresses, books and papers with visible growth are harder to save. Ask the contractor which belongings they recommend cleaning and which to discard, and document anything you discard for insurance.
Insurance
Whether mold remediation is covered depends on your policy and the cause. Coverage is more likely when mold results from a sudden, covered water loss than from long-term leaks or humidity. Call your insurer early and keep records.