Mold removal is a three-step process. First, it includes the mold assessment phase to document the problem through an inspection as well as mold testing to assess the degree of mold contamination; second. the mold remediation phase to fix the problem; and, finally the post-remediation phase which insures that the mold remediation has been performed properly and the air quality is within the normal range.
Mold Assessment Phase
The mold inspector tests the walls in problematic area with a moisture meter to determine the level of moisture, he notes the relative humidity (RH) of the air, documents the problem, and takes pictures. After completing his mold inspection, the inspector makes recommendations regarding mold samples.
Based on the problem, he will recommend collecting various mold samples which he will be sent to an independent accredited laboratory. Samples can include:
- Air samples to test the ambient air for mold spores with one outside as a control.
- Wall or ceiling cavity sample(s) if walls or ceiling are suspected of having mold growth.
- Surface samples to collect mold-like substances.
- Carpet samples.
- Bulk samples – a piece of drywall, carpet strip, etc.
The Mold Assessment Report should include as a minimum:
- A description of the mold contaminated location, and pictures.
- The relative humidity of the air.
- The moisture content in walls if higher than normal.
- The laboratory results as well as the mold inspector’s interpretation of the results.
- The source of water intrusion/leaks/moisture if known. If the mold inspector is unable to find the origin of the problem, the inspector will recommend hiring an expert, such as a building engineer, a roofing company, or any other expert. He will stress that repairs be made prior to mold remediation.
- Recommendations – a detailed mold remediation protocol that describes the scope of the work to be performed, and how to remove the contaminated area safely.
NOTE – The mold remediation protocol may be included in the assessment report or may not, depending on the extent and complexity of the problem. It can be a single page or twenty pages, or more.
The Mold Remediation Phase
Mold remediation, also called mold mitigation or abatement, involves the physical removal of the infested medium in a safe manner for the workers and occupants.
During this process mold will be disturbed and millions of spores will become airborne. It is thus essential that proper precautions be taken beforehand to protect the workers and the occupants, as well as setting up containment to prevent the mold spores contaminating adjacent areas.
Containment is the process of isolating a mold-contaminated area with polyethylene sheeting to prevent spores from spreading to the rest of the home or building. The containment area is kept under “negative pressure” so that the mold spores floating in the air will be drawn into the work area and be picked up and removed by the air scrubber. There can be full containment involving the entire room, or partial containment involving part of a room. The size and extent of mold contamination will dictate the type of containment.
The mold remediation includes removing the contaminated sheetrock, sanding the contaminated wood or replacing it, or soda or dry ice blasting large contaminated areas to remove any embedded mold and hyphae, and disposing of the infested materials safely.
Post Remediation Testing
Post-remediation testing, also known as a clearance test, insures that the mold remediation has been performed properly, as evidenced by laboratory results. This testing is performed after the remediation is completed, but before the containment is removed and before any reconstruction takes place, such as installing new drywall.
The testing is carried out inside the containment area while the containment is still intact, and at least one air sample, preferably two are collected to be compared to one outside sample. It is best that the clearance test be performed by the same company that performed the original testing. This will ensure that the same methodology is followed – the same volume of air collected, the same brand of spore traps employed, and the services of the same laboratory utilized. This will provide greater accuracy when comparing the levels of mold spores before and after remediation.
Once the mold inspector receives the laboratory results indicating that the air quality inside the containment is normal compared to the outside sample, the mold inspector issues “air clearance,” which means that the remediation was performed properly. In the event the laboratory results still shows a problem, the inspector recommends that additional remediation is performed.
NOTE OF CAUTION – The process of mold removal involves two separate professional companies. The mold assessment and post-remediation should be performed by a mold assessment company, while the mold remediation should be perform by a mold remediation company. This is to avoid a potential conflict of interest.