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(s) of Assessment: September 12 and 23, 2022
The picture frames noted were impacted by mold growth on the back and within the frames. They had been moved into the main office prior to the assessment.
No odors or visible mold growth was observed on surfaces within the office (walls, furniture, etc.).
Areas above the drop ceiling were assessed. No moisture sources were identified above the drop ceiling.
The carpet was probed with a moisture meter. No elevated moisture was detected.
The wall the pictures were leaning against was probed with a moisture meter. Moisture readings were not significantly elevated, however they were slightly above what would be considered baseline. This prompted further assessment in association with the wall cavity.
The cove base was removed from the back wall (exterior wall) of Office 36. Brown/Black staining was observed on the bottom one inch of the cove base. The staining was sampled (tape lift) confirming the presence of mold.
An inspection hole was cut into the drywall to observe the wall cavity. The cavity contained fiberglass insulation. The exterior wall (viewed from inside the building) was observed to be constructed of plywood. No mold growth was observed on the plywood, insulation, or the backside of the drywall. Elevated moisture was not detected in the plywood.
A historical review (construction documents/historic aerial photographs) was completed. It was found that the office in question as well as two other offices (38 and 39) were part of an addition to the school in 2004-2005.
- The addition included three student services offices (slab-on-grade) which are interconnected with the original school building.
- The construction documents as well as onsite observations indicate that the offices have a stucco panel exterior siding adhered to plywood.
The Office of the Environment and Building Maintenance reviewed the exterior of the addition (includes all three offices). The following deficiencies were identified:
- Nail pops were observed indicating the exterior paneling was not fully adhered.
- Gaps were observed in-between exterior paneling.
- The trench drain around the exterior of the addition needed to be reset as it had shifted over time.
- The grading could be improved to better drain water away from the building.
The walls were later probed with a moisture meter (on a less humid day) and no elevated moisture was detected in the wall.
Based on the moisture content in the drywall shifting (up/down) with exterior humidity, the Office of the Environment believes that the building envelope was poorly sealed. This allowed humidity to rise within the wall cavity via diffusion during times of high humidity outside (typically Summer). Because drywall does not necessarily touch the floor when installed, a small gap allowed wall cavity air (hot/humid during Spring/Summer) to escape and contact the cove base. Because the cove base was located in a conditioned space within the building (cooler), condensation likely formed on the backside of the cove base, causing subsequent mold growth.
The humid conditions associated with the wall cavity likely transferred condensation/humidity into the areas surrounding the picture frames as they were reported to have been leaned against the wall over the summer.
It should also be noted that the wall adjoining the main hallway (to modular classroom section) is constructed of block (identified during drywall removal, see corrective actions). A crack was observed in the block wall.
As part of this assessment the additional two offices and common hallway in the addition were assessed:
- No elevated moisture was detected in the drywall or carpet.
- The cove base was assumed to be impacted by the same condition noted above. The cove base was not removed for assessment as not to disturb/create an exposure pathway.
- An inspection hole (already present, not installed during this assessment) was assessed in Office 39. A draft was noted within the drywall cavity. This draft was found to be associated with a hole in the block wall outside of the office. Additionally, "daylight" was observed where the exterior paneling should connect to the framing.
- Areas above the drop ceiling were assessed. Suspect mold growth was observed on the backsides of the supply diffusers within the Guidance Area (excludes Office 36). This can occur due to high summer time humidity or over cooling which causes condensation on the metal diffusers. Because the mold growth impacted the backside of the diffuser (not within the air stream), the plenum area being under negative pressure (smoke tested), and due to the limited amount, this condition was not expected to significantly impact indoor air quality.
Building Maintenance (HVAC) removed and replaced the impacted supply diffusers.
Building Maintenance utilized a contractor to perform the following exterior repairs to the Student Services addition:
- Re-adhered the exterior siding with screws instead of nails.
- Caulked the joints where each panel meets.
- Installed a z-channel on the horizontal joint to divert rain water into the trench drain below.
- Installed a drip edge at the bottom of the paneling to divert rain water into the trench drain below.
- Re-set the trench drain with paver base to limit future movement.
- Sealed the hole in the mortar outside of Room 39.
- Sealed a crack in the block wall in office where the picture frames were identified.
- Sealed the "daylight" observed around the perimeter of the addition from the inside.
The above work began on September 30, 2022 and was completed on October 24, 2022.
Additionally, Building Maintenance will be re-grading areas outside of the addition to facilitate better drainage. This work is planned to occur in the next few weeks.