Leighton Associates


The type of mold in your building will determine your course of action. Problems can range from a small patch of mold on a basement wall or in an air conditioning drip tray to the infestation of an entire room or building. On occasion, mold problems can become so severe that occupants are forced to evacuate and extensive demolition is required. Minor mold problems can usually be resolved by a conscientious building manager or homeowner. More serious problems will require professional intervention.

Small areas of mold on non-porous surfaces (e.g. hard plastic, metal and glazed tile) can be cleaned with a solution of bleach and water. Porous surfaces (e.g. fabric, wallboard and wood) which are infected with active mold, must be replaced. The individual attending to the mold should wear appropriate personal protection, make sure there is adequate ventilation, and keep others out of the work area. Scrubbing large areas of mold can release dangerous particles, risking health problems. So, for areas of mold larger than a few square feet, seek the assistance of a professional.

Significant mold problems (in terms of quantity and/or persistence) generally require a four step process to resolve them: investigate the problem, stop the cause, remove damaged materials, and restore the environment.

Investigate the Problem

The first step is to determine if mold is the problem and if it is, the source and type of mold. This is accomplished by a combination of visual inspection and scientific testing. Testing can determine or confirm the existence of mold (which may or may not be visible), and the type(s) of mold present. Results will also indicate potential health problems and the degree of safeguards and skill needed to correct the problem. The collection and analysis of samples can take a week or more, so it is important to proceed with the next two steps while awaiting test results.

Stop the Cause

Mold is almost always due to an excessive moisture problem. Therefore, it is critically important to find the water source and to stop any further water ingress. The source may not be obvious because mold does not necessarily require the presence of standing water. There are any number of possibilities including high relative humidity, heavy condensation, poor ventilation, and malfunctioning HVAC systems. Unless the moisture source is stopped, mold growth will continue even after abatement.

Remove Damaged Materials

Once the moisture problem is corrected, the contaminated materials must be removed and all affected areas must be dried thoroughly as soon as possible. As a rule, all affected porous materials (such as paper, wallboard and fabric) are discarded rather than cleaned. Affected non-porous items (such as plastics and metals) and semi-porous items (like wood) should be thoroughly and professionally cleaned.

Restore the Environment

If parts of the building or furnishings have been removed, they are now replaced and the environment is restored to its previous functionality. This phase may include tasks such as re-carpeting, replacing walls, re-painting, etc.


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