The situation.
An NYC-area hospital identified visible mold growth behind a wall panel on an active inpatient floor following an HVAC condensate leak. The affected wall sat between two occupied patient rooms. Vacating the wing was not an option. The facilities team needed remediation that wouldn't expose immunocompromised patients to airborne spores or move them.
The framework: ICRA Class III/IV.
Healthcare construction uses the Infection Control Risk Assessment (ICRA) framework to match controls to patient risk. For this work area, with adjacent immunocompromised patients, ICRA Class IV controls applied: full sealed enclosure, HEPA-filtered negative-air machine venting to the exterior, anteroom decontamination, and continuous pressure monitoring.
Layered over ICRA, we ran the project against NYS Article 32 and IICRC S520 — the substantive mold remediation standard.
How we sequenced the work.
Three constraints drove the schedule:
- Patient rounds and meal service couldn't be interrupted.
- Pressure relationships couldn't shift in the adjacent rooms (those rooms were on positive pressure relative to the corridor for infection-control reasons).
- The remediation itself had to be completed in a single five-day window to avoid impacting a scheduled census surge.
We staged setup, demolition and reconstruction across three after-hours sessions (7 PM–6 AM), with daytime hours reserved for moisture readings and visual progress checks behind a sealed containment.
What worked.
- Pre-job pressure mapping. Before any panel came off, we mapped airflows in and around the work zone with a thermal anemometer. The containment was sized so the HEPA negative-air machine could maintain at least −0.03 inWC relative to the corridor without disturbing the adjacent patient-room pressures.
- Continuous pressure logging. A manometer with data logging recorded containment pressure throughout the project. The PDF was attached to the post-remediation report — useful to the infection prevention team's audit.
- Daily independent walk-down. Our project manager and the hospital's IP nurse did a daily walk-down. The shared log meant no surprises on either side.
What we'd do differently.
One: more anteroom space. Our anteroom was right-sized to spec but tight for two-person decon. On the next ICRA Class IV project we'll spec a wider anteroom even if it costs a corridor lane.
Two: pre-print signage in three languages. The wing served a multilingual patient population. Standard English signage covered the protocol; bilingual signage would have made family interactions smoother.
The deliverable.
Independent post-remediation verification by a partner assessor (NYS Article 32 separation observed), pressure logs, daily photo record, and a project close-out narrative. The wing returned to full service Monday morning.