Situation

National Retailer located in a large shopping centre had insulation on concrete ceiling for part of their warehouse behind the retail shop. Due to moisture, the insulation germinated with mould where it was visible from the floor. The silver sheeting covering the insulation was deteriorating and in certain areas, it had holes in it and was coming apart in places.

The Tenant became concerned when stock was discovered covered with mould. An Environmental specialist was contacted who performed mould sampling which confirmed the insulation was contaminated. Scope of works was compiled for remediation employing methods in accordance with S520 IICRC Professional mould remediation.

Moisture Control Services (MCS) successfully won this contract by understanding the client’s needs, provided protection from cross-contamination thereby reducing work required and avoided the need to treating all offices on site while at the same time adopting S520 IICRC.

Complexities

Ceiling height of this project was 4.550 meters high where internal office section (13.4 x 3.3 metres) existed where the ceiling was 3 metres leaving a small gap to the concrete ceiling above where majority was covered with the contaminated insulation.

Large warehouse area of 110sqm approximately with racks of stock was the remaining section where the insulation existed. It was stated that the warehouse must be operational each day where it trades seven days a week.

In order to access above the office block, a network of planks was established with a fixed containment wall along the top of the offices and temporary plastic wall on the other side protecting the five open ceiling panels where ladders existed for the planks on the far side of the offices.

For the warehouse area, through a number of containment walls and custom cut 200 um plastic the racks containing stock were totally covered before remediation commenced each night.

In order to ensure trading was not affected, the total warehouse area was treated over three nights with precision placement and planning of walls where one wall was elevated off the floor with 2 metre clearance below and another small section MCS could compact against an existing rack for one day.

Containment walls and staging

Total containment walls erected and contents covered with plastic over this project measured 96 meters approximately.

Work was staged over three nights allowing for each section to be completed so that trading could take place the next day. Day 1 was the big challenge where extensive time was taken for set-up of planks over the office area. This was completed with one and half hours before opening.

Remediation

MCS used two collapsible platform ladders with wheels that allowed excellent access to remove insulation and treat concrete ceiling. Full containment was required each night so that the area was under negative air pressure. Only two small sections (2.5 metres long approximately) of containment wall needed to be moved aside and re-set the next day so trading was not disrupted. Full PPE (suites, gloves, glasses and respirator) was required when removing the insulation. This was bagged as it was removed from the ceiling thereby minimising mould spores in the air. HEPA air scrubbers were operating continuously during the night and turned off just before trading by another team member each morning. This same person also adjusted containment walls for trading because at completion of each night the affected area was extensively fogged (fine mist in the air) with an anti-microbial to treat any remaining spores in the air.

After all insulation had been bagged, the concrete ceiling plastic containment walls, covers over racking, exposed walls and floors were all HEPA vacuumed and wiped with mould cleaning solution. The only exposed wall was the back concrete wall as all side walls were covered off.

Content

This project also included treating some stock in the retail area which were HEPA vacuumed and wiped with mould cleaning solution while air scrubbers were operating nearby. Treatment of stock was performed using MCS downdraft table further minimising any form of cross contamination. At completion, total retail store and warehouse was fogged as a further pre-caution.

Clearance Testing

The Environmental specialist attended site at completion of this project to take a combination of surface and air samples to ensure the conditions were back to normal mould ecology. MCS in all cases achieved the desired outcome for air testing and 100% clearance for all surface samples taken endorsing effective treatment adopted by MCS.