Recommended Cleaning Procedure

If your property has had extensive flooding, there are two key areas of concern that should be considered during the clean up process. Both these issues are very important during the clean up process and the future health of the property and for those who will reside in the property once the repairs have been carried out.

The two key areas are;

1. Removal of the organic matter and silt from the premises
2. Removal of visual mould growth from the premises caused by the flooding

We have broken the following information up into the two key areas as the clean up procedures vary between the two key areas.

The following information we have provided is a guide only and we highly recommend these works be carried out by a professional restoration company who have been trained in the removal of black water contamination and mould remediation.

Flooded homes: Black Water contamination Cleaning Procedures

1. Category 3 Black Water
Category 3 Water is referred to as “Black Water.” Black water contains pathogenic agents and is grossly unsanitary. Black water includes sewage and other contaminated water sources entering or affecting the indoor environment. Category 3 includes all forms of flooding from seawater, ground surface water and rising water from rivers or streams. Such water sources carry silt and organic matter into structures and create black water conditions.

2. Excessive water and contaminant removal
Before comprehensive inspection and evaluation can take place, excess water and organic matter, especially raw sewage and silt, must be physically removed.

3. Initial decontamination
Initially and before handling, decontaminate sewage and organic materials by spraying with, or immersing within, a biocide solution. This treatment will not provide full disinfection, nor is it intended to do so. The objective of the initial decontamination is to commence the reduction and mitigation of microorganisms as quickly as possible. It is important to recognize that exposure to materials treated during initial decontamination poses a health risk and may result in an adverse reaction. This process must be carried out using the correct personal protective equipment and carried out in conjunction with a risk assessment and work method statement.

4. Detailed Inspection
Following the removal of organic matter, and initial decontamination procedures a detailed inspection must be conducted that considers the extent of water migration, types of affected materials and the degree of apparent damage, in order to evaluation, analyse and determine the job scope. Professional testing equipment and the principles of psychrometry must be used to formulate a plan to dry and restore, or replace, both the structure or contents materials.

5. Structural Materials
Evaluate structural materials such as panelling, plaster and wood for physical damage and degree of contamination to determine the need for removal and disposal. Demolition of structural materials maybe required to expose pockets of contamination for cleaning and drying.

6. Floor Coverings and Sub-floor
If a category 3 penetrates underneath timber, laminate floating floor, vinyl flooring, tile, stone or other floor coverings that may otherwise be deemed salvable, remove and property dispose of those materials. Subflooring materials must be fully evaluated for restorability. Subflooring components, if salvable, must be cleaned, disinfected, dried and sealed, as necessary.

7. Flush/Cleaning
Residual organic matter in cracks and crevices of salvable materials normally can be removed by flushing with a cleaner/disinfectant solution. Recover the flushing solution with an extraction unit immediately after application to prevent further migration or absorption of contaminates into other porous materials. In some situations, using pressurized washing to adequately flush contaminates out of cracks, crevices and from under structural components.

8. Waste Disposal
Category 3 water removal of organic matter, sewage and silt must be disposed in a sanitary sewer system.

9. Detailed Cleaning & Secondary Biocide Application
After removing heavy organic soils and contaminates, thoroughly clean removing materials or components before a second application of a biocide. Cleaning helps reduce the amount of organisms present so that subsequent biocide applications are not rendered ineffective by organic soils. Lack of meticulous cleaning may render biocide applications ineffective. Thorough cleaning is required before implementation of additional procedures.

10. Structural Drying
Procedures should be implemented to increase the rate of drying. It is recommended that moisture and humidity be reduced as much as possible by introducing air movers and dehumidification to increase the rate of drying.
It is recommended that a closed or mechanical dehumidification drying system be used for the restoration of properties . An open drying system (Leaving the windows open with the use of air movers to create evaporation) can only be used when the specific humidity of the outside air is less than the specific humidity of the inside air.
It is recommended that the building materials are dried to the buildings dry standard before any re-construction works can be carried out to prevent any future mould growth.

Mould Remediation (Condition 3) Procedures

1. Condition 3 (Visual Mould Growth)
An indoor environment contaminated with the presence of visual mould growth and associated spores. Actual growth includes growth that is active or dormant, visible or hidden.

Condition 2 (Settled Spores) An indoor environment which is primarily contaminated with settled spores that were dispersed directly or indirectly from a Condition 3 area, and which may have traces of actual growth

Condition 1 (Normal Fungal Ecology) An indoor environment that may have settled spores, fungal fragments or traces of actual growth whose identity; location and quantity are reflective of a normal fungal ecology for similar indoor environment

2. Air filtration Devices
It is highly recommended that prior to the cleaning and remediation of a Condition 3 mould contamination that an Air Filtration Device is used and is located in an area where remediation activities are being conducted. It is highly recommended that the air filtration device is fitted with HEPA filters.

3. Removal of Contaminated Structural Materials
It is highly recommended that porous building materials with mould growth penetrating the surface (classified as Condition 3) be removed and discarded appropriately. Mould growth on framing members can usually be removed by using HEPA vacuuming or damp wiping followed by sanding and wire brushing. It is important to recognize that exposure to materials contaminated with mould poses a significant health risk and may result in an adverse reaction. This process must be carried out using the correct personal protective equipment in conjunction with a risk assessment and work method statement.

Spraying, wetting or misting of mouldy building materials in preparation for removal, is not recommended because spores may be released or dispersed by the spray and the added moisture presents potential problems for mould amplification.

4. Detailed Structural Cleaning
To achieve Condition 1 status in the work area after demolition has been completed, it is important to thoroughly remove all visual mould, dust and debris from all surfaces, internal wall frame etc. It is highly recommended that periodic HEPA vacuuming or wet wiping of all surfaces in the remediation areas be performed to remove settled dust and spores. It is also important to recognize that exposure to materials contaminated with mould poses a significant health risk and may result in an adverse reaction. This process must be carried out using the correct personal protective equipment in conjunction with a risk assessment and work method statement.

One of the goals of mould remediation is to leave surfaces clean and dry. Source removal of contaminated porous materials is the preferred method for mould remediation.

The use of treatments such as ozone or ultraviolet (UV) light as a substitute for the removal of mould is generally not recommended

5. Wet Wiping & Treating Contaminated Surfaces
The product that we recommend for the final treatment of contaminated surfaces be carried out to kill and inhibits the growth of mould and odours, when used as directed.

Remediation Steps
1. Install air filtration device (air scrubber fitted with HEPA filters) and locate closely to the area being remediated.

2. HEPA vacuum all surfaces of the wall frame or any surface that is deemed to be a Condition 3 contamination.

3. Treat all surfaces (including wall cavities) affected by a category 3 black water contamination and a Condition 3 contamination with an effective anti-fungal product.

4. Cleaning of all affected surfaces is to be carried out via scrubbing, agitation, brushing, sanding of the affected surfaces for the removal of contaminates.

5. Pressure cleaning of the bottom plate, crevices and cracks may also be required for the final removal of contaminates.

6. On completion of the cleaning a further application of anti-fungal solution to be applied to mitigate and reduce the levels of bacteria and mould.

7. Once the cleaning has been meticulously completed, drying of the buildings structure is to occur by using mechanical drying methods, such as introducing air movers, heat drying and dehumidification to the premises.

8. It is recommended that the building materials are dried to the buildings dry standard before any re-construction works can be carried out to prevent any future mould growth.

References: IICRC (International Inspection Cleaning & Restoration Certification) S500 & S520 Standards and guidelines.
Australian Mould Guideline AMG-2005-1
For further information refer to www.juvenaire.com


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