Post-Remodel Silica & Drywall Dust: 3-Stage HEPA Decontamination
A gut kitchen and master bathroom renovation left fine respirable crystalline silica (RCS) and gypsum dust coating 3,200 sq ft of living space through an unsealed HVAC return duct.
Containment & Equipment Deployed
- • 2x Commercial Air Scrubbers (Dri-Eaz DefendAir HEPA 500 CFM)
- • Class L/M/H Certified HEPA Vacuums with soft horsehair attachments
- • Laser Particulate Meter (TSI DustTrak Airborne Particle Counter)
- • High-reach electrostatic microfiber damp poles
Chemical Formulations & Dwell Protocol
- • Deionized water + antistatic surfactant damp wipe solution
- • pH 7.0 neutral rinse for finished pre-finished hardwood
- • Citrus-based natural adhesive remover for fixture tape residue
Itemized Financial Audit & Settlement
Primary Engineering Takeaway
"Never dry sweep drywall or silica dust. RCS particulates stay suspended in household air for over 12 days and cause permanent lung fibrosis."
The Underlying Challenge
A general contractor completed a $180,000 renovation but failed to isolate the HVAC return registers. When the HVAC fired up, 20 lbs of crystalline silica and sheetrock dust were blown into every furnished bedroom, upholstery, and wardrobe.
The Scientific Remediation Protocol
Technicians established negative air containment and deployed 1,000 CFM of continuous HEPA air filtration. Dry sweeping was strictly banned under OSHA 29 CFR 1926.1153. A 3-stage protocol was executed: (1) Top-down HEPA vacuuming with soft-bristle brushes, (2) Electrostatic damp micro-wiping with deionized surfactant, and (3) Air scrubbing for 24 hours post-wiping.
Quantitative Verification & Clearance Result
Laser particulate monitoring confirmed PM2.5 air levels plummeted from 340 ug/m3 to 8 ug/m3 (clean mountain air quality). The GC's liability insurer reimbursed 100% of the decontamination invoice directly.