Fire & Water - Cleanup & Restoration

Mold Cleaning and Remediation is a Job for Professionals

5/12/2016 (Permalink)

Mold Remediation Mold Cleaning and Remediation is a Job for Professionals A leaking pipe that went undetected for an extended time period allowed extensive mold growth that was concealed by furniture.

Visible mold growing inside your home or business may pose serious health risks for some people, and it should be properly removed as soon as possible.

Mold spores in Columbus or elsewhere, which are similar to the seeds of a plant, are microscopic in size and ever-present in the air and on surfaces, both inside and outside of buildings. All that is necessary for mold spore to take root and grow is a growth medium, sufficient moisture, and time.  A bit of dust, or soil, or food residue on any surface (even concrete or tile) is enough to serve as a growth medium for mold or other microbes.  Porous materials such as carpet or drywall can be an excellent growth medium.  Humid conditions combined with warmer temperatures can accelerate the growth of some types of mold.  When moisture remains in a suitable growth medium for more than a day or so, mold and other microbial growth is possible and likely, which is why keeping surfaces of indoor environments clean and dry is important.

Once mold in Columbus becomes visible to the naked eye, it is usually active and growing. The expression "Black Mold" is often used when it is visible.  When this occurs in the built environment, it may be cause for concern, and you should contact a mold remediation professional, to perform an inspection.

The restoration technician will begin by checking for wet conditions in the building.  Since moisture plays a key role in the growth of microbes, the amount of moisture present in the air, the building contents, and the building materials must all be taken into consideration. The technician will attempt to determine the source of the excess moisture.  Any leaks or other sources of excess moisture must be addressed.

 The technician may employ any of several methods and devices to measure the moisture in each of the areas above.  The tool used most commonly by technicians for measuring moisture in the air is a thermo-hygrometer (sometimes called a psychrometer), which is essentially an electronic psychrometric calculator.  The primary readings use by the technician are temperature and relative humidity.  The readings from the psychrometer may also be inserted into a psychrometric chart. From this, the technician can see the relationship between relative humidity, temperature, dew point, and the humidity ratio.  Relative humidity is the percentage of moisture in the air compared to how much moisture the air is capable of holding at a given temperature.  Dew point is the temperature at which water will begin to condense from the air onto surfaces.  The humidity ratio is the actual amount of water vapor in one pound of dry air, usually expressed as a ratio of grains of water vapor per pound of air (GPP). 

 There are several tools used to determine the moisture content of the materials in the building.  A non-penetrating moisture meter will measure to a depth of approximately 3/4 of an inch.  Most have separate settings for wood, drywall, or masonry.  Wood moisture content is measured as a percentage, while other materials use a points scale.

 A pin-type penetrating moisture meter is employed to check for moisture deeper than 3/4 nch, or if there are wet materials behind a wall or under a floor.  It has probes that must be driven into or even completely through one material to check for moisture in another, such as insulation behind drywall, or subfloor materials beneath a vinyl rug. 

Another method for finding wet materials that may not be visible to the naked eye is with an infrared camera.  Infrared cameras are extremely sensitive, with the ability to detect temperature differences to as little as .05 degree Fahrenheit. They can enable the technician to locate wetness in buildings that cannot be found using conventional moisture meters.

The moisture levels in most materials must be measured against a 'dry standard', which will vary with local environmental conditions.  The dry standard for materials in a building along the Gulf of Mexico will usually allow for a higher normal moisture content than for materials found in a building in the Desert Southwest for example.  The technician will take readings from an area of the structure, or a neighboring structure, that has not been affected by the water damage event to set a 'drying goal' for each type of material, which will approximate the dry standard.

When a building incurs a water loss, the level of wetness is classified, and the level of contamination is categorized according to standards established in the S500, a manual by the Institute for Inspection, Cleaning and Restoration Certification and Training (IICRC).  Water damages are divided into 4 Classes.

- Class 1 water damage is the least amount of wetness, confined mainly to the floor with only part of a room or area affected and little or no wet carpet or carpet pad. 

- Class 2 is a large amount of water, with very wet flooring materials in at least an entire room and moisture wicking up the walls no more than 24 inches. 

- A Class 3 water loss is the greatest amount of water, with entire rooms saturated from ceiling to floor, where water may have leaked down from above. 

- Class 4 is a Specialty Drying situation, with hard to dry materials such as concrete, plaster or masonry, and deep pockets of saturation, which may require very low humidity or heat to dry. 

Water contamination is broken into three categories:

- Category 1 water is water from a clean or sanitary source, which may be from a broken supply line, or toilet tank or bowl. Category 1 water can degrade over time to Category 2 or 3 with exposure to higher temperatures or contaminants, such as animal feces or animal carcasses. 

- Category 2 water is mildly contaminated, and may cause illness or discomfort if ingested.  Sources of Category 2 water may include a washing machine or dishwasher overflow, toilet overflow with no feces or a small amount of urine.  Category 2 water can degrade to Category 3.

- Category 3 is grossly contaminated water which would likely cause serious illness or death if ingested.  Examples include sewage, intruding water from flooding rivers or streams, toilet back-ups that include feces, or water that has been sitting long enough to support microbial growth.  Water associated with a significant mold loss is generally considered to be Category 3. 

If mold is discovered or suspected, samples must be taken from surfaces inside the building, and from the air both outside and inside of the building.  The process of taking samples may require somewhat intrusive measures, such as moving furniture, lifting carpeting, opening air condition ducting, or even removing sections of drywall or flooring.  The samples are taken to a laboratory and examined under a microscope by to identify the type and quantity of any microbes present.  The results for the interior and exterior samples are compared against each other.  The quantity of mold spore for a given volume of air should be somewhat less indoors than outside.  The type and quantity of microbes normally present in the local environment are also taken into consideration.  It is not uncommon in cases of serious interior mold infestations that the quantity of mold spores discovered in the interior air samples is significantly higher than the outdoor sample.  Another indicator of an interior mold problem is the presence of a significant quantity of spores from the indoor air sample that are of a different type than the majority of spores present in the outdoor air sample.

When the results of the laboratory analysis are positive for mold, a remediation protocol is developed.  This protocol must be followed by the mold remediation professional. 

Before the remediation can begin, any standing water must be removed from the environment. Air scrubbers may also be installed inside the building.  Air scrubbers are high-efficiency particulate arresting (HEPA) air filters, which remove 99.97% of particles from the air, down to a size of .03 microns.  This filtration level is fine enough to capture mold spore, which can help reduce the amount of it in the air, and the likelihood that the mold will spread. 

Technicians must don the proper personal protective equipment (PPE) before beginning the remediation.  This usually includes impermeable gloves and suit, a respirator and eye protection.  The remediation technicians will construct a containment barrier around the affected area, to close-off unaffected areas from the remediation process. Slight negative air pressure should be maintained within the containment, with any air exiting the chamber also filtered through an air scrubber, to reduce the likelihood of cross-contamination of unaffected areas.

Any wet and contaminated, porous materials, such as carpet or upholstered furniture, must usually be discarded.  Materials to be discarded must be sealed in a container (such as a trash bag) while still within the containment area.  Once removed from the building, it can be tossed out with normal construction waste. 

Standing water must be extracted. Extraction is normally accomplished using a powerful portable unit that is capable of pulling a strong vacuum.  Truck mounted extraction is less common in the presence of mold. 

Once standing water has been removed, any remaining residual moisture must be removed from materials to be saved through dehumidification.  Commercial dehumidifiers are usually employed to achieve low relative humidity levels.  Low grain refrigerant (LGR) dehumidifiers are used with larger losses and higher moisture levels, as they are capable of discharging air at even lower humidity levels.  However, refrigerant dehumidifiers must operate within a relatively narrow temperature range to achieve maximum effectiveness.  Desiccant dehumidifiers are capable of achieving extremely low humidity levels in a wide range of temperatures, but they require a method to discharge moist air from the environment, which may not always be feasible, especially in the presence of mold. 

When materials such as concrete or plaster become saturated with moisture, they can be difficult to dry, and will usually take much longer than materials such as wood, drywall or carpet.   Heat may be added to the drying process in this case.  However, heating the materials or the drying environment can also stimulate mold growth, and should not be employed on a mold job until humidity levels have been reduced below 50%. Air movement may also be applied to aid in moisture removal, although this too is often curtailed in the presence of mold, to prevent spreading and cross-contamination.

It is not uncommon for the subfloor and structural members of a building to be contaminated with mold as well.  Solid wood flooring or structural wood can be sanded or otherwise abraded to remove mold.  HEPA vacuum equipment is employed to capture all of the dust and debris created by this process. The depth of material that must be removed will be specified in the protocol.  Since the integrity of some structural members can be compromised by sanding or grinding, it may be necessary to consult with an engineer to determine how much material can be safely removed before having to be replaced. 

The goal of a mold remediation is to remove the mold from all surfaces, or remove and discard material where the mold cannot be remediated.  In some cases, it is extremely difficult or impossible to remove material or remediate the mold from it.  In those cases, the mold may be sealed off using an approved an encapsulant.

Once the remediation is complete, the containment barrier can be disassembled, and any reconstruction can begin.