Mould remediation

Level 3: extensive outbreak

This level applies to an extensive outbreak or to any case when a serious enough property threat is deemed to exist to warrant the best remediation affordable/obtainable.

This category of remediation would always involve a team approach. The team would include:

  • remediation coordinator/project manager;
  • professional damage management contractor;
  • tenant/occupier liaison;
  • services engineer;
  • architect/building surveyor;
  • mycologist/indoor air consultant;
  • building contractor/subcontractors; and
  • leak detection specialist.

A legal consultant may also be required for very large, complex or sensitive projects.

There are only a few agencies in the UK that can offer this level of mould remediation, which includes all of the elements of remediation contained in the first 2 remediation levels, but in addition a holistic approach to mould remediation.

A much greater emphasis would be placed on:

  • scientific appraisal of the colonisation;
  • monitoring of building condition leading up to the site remediation and during the remediation; and
  • post-site works to appraise the remedies and systems applied to maintain good air quality and satisfactory building condition.

Decontamination chambers are probably only used in the most severe and extensive mould colonisation or where there is a considerable threat to health from it. We are now moving into the kind of extremely rigorous approach we might associate with asbestos removal contracts (when even 3-chamber decontamination chambers are used). It is worth consulting the mould standard IICRC S520 here, should you wish to know in detail the kind of careful approach that may be necessary to remediate the most serious mould colonisations. Even the air scrubbers and air movers are encapsulated in plastic wrapping before their removal from site at the end of the cleaning operation.

We may rarely become involved in the kind of remediation described in the mould standard, but still need to be aware of the general principles of remediation contained within it, which could still apply to the less serious mould clean-ups.

Level 3: checklist for cleaning extensive mould

Depending on the circumstances, a team leader or project manager may or may not be required.

Measures in addition to level 1 trivial mould advice.

  • Organise decanting of tenants or occupiers to either a separate building or a mould-free zone.
  • Organise a mould remediation team.
  • Fully investigate cause of moisture imbalance, including full survey investigation using leak detection specialists, dampness investigation consultant or building ventilation and heating specialist.
  • Remediate obvious cause of water damage.
  • Design improved indoor air environment by devising and installing lifestyle or other environmental change and improvement.
  • Pre-mould remediation survey (usually destructive) to include opening up, material testing and/or air sampling.
  • Operatives should wear suitable PPE.
  • Erect necessary compartmentation screening between contaminated and uncontaminated zones.
  • Erect source and local area containment.
  • Prepare 2- or 3-chamber decontamination facility, if needed.
  • Create negative pressure chamber to limit release of spores/fungal fragments outside the treatment zone.
  • Clean the mould using HEPA filter vacuum equipment, or other equipment as needed.
  • Remove contaminated materials encapsulated in plastic sheeting or in plastic bags.
  • Undertake necessary post-remediation restoration works.
  • Ensure treated area is mould-free and ready for reoccupation.
  • Check treated building zone is mould-free on completion of mould remediation, conduct post-remediation monitoring of building air and fabric.
  • Monitor health of building occupants post remediation.
  • Evaluate mould remediation exercise and further develop techniques for future contracts.