Before remediation can commence the source of moisture must be identified and permanently fixed otherwise mould will most likely return.
Remediation process generally adopts the following stages:-
Stage 1 - containment
Containment is the first stage to minimise area treated and prevent cross contamination:-
- Plastic containment wall is erected around/across the affected area(s) with zip wall access.
- Items within the containment area if unaffected can be covered in order to minimise treatment and protection of contents.
- Laminated posters will be placed at the entry warning all persons of mould remediation in progress.
Stage 2 – negative air pressure /posters
In order to filter the air of any airborne mould spores during destructive work and to keep the area under negative air pressure which further reduces any chance of cross contamination, HEPA (acronym for “high efficiency particulate air/air restance” filtration system that removes 99.97% of all particulates down to 0.3 microns) rated air scrubbers will be installed and ducted outside to expel clean filtered air.
Stage 3 – Affected contents
Contents in the affected room(s) will need to be treated. All content items are inventoried, boxed, outside of box HEPA vacuumed at zip wall and moved outside. Depending upon volume and on-site facility contents can be treated on or off site.
Stage 4 – destructive work
This includes the physically removal of building structure that cannot be treated. It can include but not limited to floor-coverings, smoothedge, skirting boards, walls, ceilings, cornice, door and wall frames etc. All affected sections are bagged immediately into 150um plastic rated bags or wrapped in plastic for disposal. Timber wall frame and base plate at times require more aggressive treatment to remediate mould (e.g. use of electric sander , wire brush) and at times section of the base plate or wall frame may need to be removed if beyond restoration and/or has decayed.
Stage 5 – mould treatment / drying
Initial treatment includes HEPA vacuuming all horizontal and vertical surfaces (ceiling, walls, floors, window sills, timber wall fame/base plate etc.). Second stage is wiping all horizontal and vertical surfaces (ceiling, walls, floors etc.) with the mould cleaning solution applicable for the item being treated. Final stage is a second wipe of all affected items as per second stage.
If the building structure has elevated moisture, this will need to be dried during this process after the initial treatment. Also fogging (fine mist in the air) with anti-microbial solution may occur to treat any mould in the air.
Stage 6 - clearance sampling
Mould surface and air sampling would then be conducted in order to obtain a clearance report confirming the environment is back within normal mould ecology (report takes 4-6 working days). Occasionally, additional treatment is required which is why HEPA air scrubbers and containment walls remain in place until clearance is received. When clearance report is achieved then the repair work can commence after MCS removes equipment and containment wall.
In situations where it is not possible to perform extensive inspection and where remediation work takes place, it is possible that there will be “discovery” of hidden mould damage. Any escalation to carry out additional remediation due to the discovery of hidden mould during the remedial works will be assessed, cost estimate calculated and approval gained from the client to proceed.
Importance of clearance report
Once remediation has been completed, mould sampling is re-conducted and results analysed, compiled and returned to the client. These results are very important to a number of parties:
- To MCS as it proves the work completed has decontaminated the affected areas.
- To the client as it is evidence that their facility is safe for all staff, visitors or contractors who attend such areas. Such results will also protect the business from any unknown future liabilities/claims which may be lodged at a later date by people who think they may have been affected at a point in time.
- To staff/tenant property owner as it provides confidence that proper action has been taken and their safety has been protected.