The Fundamentals of Mould Remediation
In all situations concerning mould growth indoors that requires remediation, the underlying cause of moisture that is supporting the growth must be repaired or fungal growth will recur. There should be an emphasis in the remediation works for the cause of moisture damage to be permanently repaired so that water damage does not recur.
It should be kept in mind that the goal for mould remediation is not to sterilize surfaces, but to return surfaces to their normal state before mould contamination. In addition, the containment, PPE, hazard contamination, and cleaning guidelines in this document are not definitive. Each remediation job needs to be assessed on its own merits and the people performing the remediation work should ensure that adequate protection measures are taken.
The 11 Fundamentals of mould remediation can be categorized into 3 stages.
- Stage One; Assess, Inspect, Define and then Notify
- Stage Two; Fix, Remove, Dry, and then Clean
- Stage Three; Clear, Return and then Hand Over
In essence every mould remediation project should follow this basic process:
- Assess the level of mould damage (PPE)
- Inspect to find the cause of the mould damage
- Define and agree on the scope of works (SOW)
- Notify all tenants and occupants of the SOW
- Fix the original problem with a permanent solution
- Remove contents and remove contaminated materials
- Dry the structure to equilibrium
- Clean all affected air and surfaces
- Clear the area for reuse with air and surface testing
- Return all restorable and decontaminated contents.
- Hand over the property to the client.
Fix the Problem – Permanently
The underlying cause of mould growth must be permanently fixed. Failure to do this may result in recurrence of mould growth and subsequent failure of clearance testing. When assessing the underlying cause, consideration must be given to the two main sources of moisture causing mould growth in a building, which are:
- Moisture created within envelope (such as condensation, HVAC settings, low dew point temperatures, poor insulation, un-flued gas heaters, humidifiers, etc).
- Ingress from outside building envelope (including flooding, broken pipes, overflowing gutters, showers, dishwasher, fridge ice makers, garden sprinklers, etc).
Discovery of Hidden Damage During Remediation
There are often multiple sources of moisture. Discovery of other sources often odours during remediation. All discoveries of sources of moisture must be and will be communicated to the client immediately.
Clearance testing should be performed on larger jobs before occupants and tenants are allow to reuse the area being remediated. The testing should be undertaken by an independent mould testing and analysis laboratory, if no one is available then testing by the remediation company is recommended to ensure the cleaning has passed.
Failed clearance testing;
- Re-clean if necessary
- The onus is on the remediator to do the extra cleaning
- Search for hidden mould sources
- No warranty for non-disclosed events by the client.
Returning Contents after Clearance
Contents should only be returned to a cleared area after they have been cleaned and have passed their own clearance testing. Only return contents that were held under your control. Contents that were not originally there or were removed by the owner, should not be returned until after the area has been handed back to the client.
Hand Over to the Client
- All remediation as per SOW
- Site is left in a clean and tidy state
- Walk through inspection of contents that were cleaned
- All equipment is removed from site
- Laboratory clearance testing report.