Identify deficiencies that may impact IEQ and/or sources of odor concerns. Typically includes the following depending on the nature of concern, but not limited to:
- interview/questionnaire of concern individual(s)
- inspection above drop ceiling (condition of roof deck, pipe insulation, return air plenum)
- inspection of ventilation system (operation of variable air volume box and outdoor air dampers, check controls, measurements of carbon dioxide, temperature and relative humidity, sources near outdoor air intake, measure return and supply air volume, cleanliness of coils, liner and condensate pan)
- inspection of exterior
- inspection below drop ceiling (housekeeping, sink and floor drain traps, signs of past and present moisture concern via visual and/or moisture meter, mold growth, ensure connection of current and capping of abandoned sanitary vents, odorizers, excessive plants and fabric items, identify potential pathways, and measure volatile organic compounds, carbon monoxide, and lighting)
Date of Assessment(s): July 7, 9, 16, 20, 29, August 3, 11, and 31, 2020
A strong odor indicative of wood was identified within the portable.
A strong musty/mold odor was identified in one room of the portable (2nd Door on Right when viewing portable with school behind you).
Visible mold growth was not identified during the initial visit.
Elevated humidity (72.3%) was identified in the portable.
The HVAC systems were operational originally and were not supposed to be, per the Summer HVAC Policy. The Office of the Environment requested that the portable's HVAC systems be turned-off per the policy to determine if the HVAC system was contributing to the elevated humidity levels.
Elevated moisture was not detected in the carpet or drywall.
Data loggers were placed in the portable to monitor temperature and relative humidity, to further investigate the odor and elevated relative humidity.
The remaining portables at the school were assessed. No odors, humidity, or mold concerns were identified.
After reviewing the trends from July 9-16 it was determined that the operation of the HVAC system prior to July 7, was likely not causing the humidity concerns within the portable. On the 16th, the Office of the Environment requested that Building Maintenance (HVAC) close the outside air dampers of the portable's units and operate the system to help reduce humidity levels during the assessment phase of the project.
Building Maintenance (HVAC) completed the above referenced work.
Further investigation identified extremely elevated humidity (100%) between the fiberglass insulation (above the drop ceiling) and the roof deck (plywood). The fiberglass insulation is directly up against the roof limiting visual assessment and moisture content readings. The elevated humidity between the fiberglass insulation and roof deck indicated a possible roofing issue.
Building Maintenance (Roofing) was contacted to assess the roof. Minor pinhole leaks were identified and sealed. These small leaks were not thought to be the source of the elevated humidity within the portable.
Additionally, while assessing above the drop-ceiling suspect dust/debris was observed uniformly distributed across the wood framing of the portable (above the ceiling), throughout the portable. This observation was believed to be mold growth. A tape-lift sample was collected for confirmation. The sample indicated elevated fungal spore counts, confirming the presence of mold growth.
A board-approved contractor then removed the fiberglass insulation for further assessment, as it would need to be removed anyway as part of the cleaning process.
Black staining and elevated moisture was identified in association with the plywood roof deck, again indicating a possible roofing issue.
Building Maintenance worked with a Building Envelope Specialist to assess the portable after the fiberglass insulation had been removed. The Building Envelope Specialist determined that the most likely cause of the elevated humidity within the portable was that the EPDM roof, which was applied directly to the plywood roof deck, condensation on the underside of the EPDM then migrated through the plywood deck and then was heated (summer), elevating the humidity within the portable, particularly above the drop ceiling, subsequently causing mold growth.
A board-approved restoration contractor removed the existing fiberglass insulation above the drop-ceiling and discarded it. The wood framing above the drop-ceiling was cleaned. The plywood decking was then dried before moving to the next phase of the project, which included encapsulation of the wood framing. After work was complete, surfaces (desks, chairs, tables, etc.) were cleaned as a precaution. Work began on August 7, 2020 and was completed on August 28, 2020.
A new roof with additional insulation is currently being designed to prevent the current EPDM roof from forming condensation. The new roof is to be installed as soon as possible. Ideally, the new roof should have been installed prior to the cleanup to prevent further growth and the need for re-cleaning. The Office of the Environment will monitor the portables humidity levels for the month of September (hotter weather). Dehumidifiers may be needed to prevent the condition from occurring in the mean-time.