Protecting Buildings from Wildfire Smoke: A Guide for Owners and Facility Managers

Wildfire smoke keeps showing up far from the actual fires, and the tiny particles it carries (called PM 2.5, particles 2.5 microns or smaller) can travel hundreds of miles and slip into homes no matter how sealed they are. Along with smoke particles, wildfires release volatile organic compounds (VOCs) and gases like formaldehyde and carbon monoxide, plus ash, which can affect outdoor air quality in a region for up to two years.

If your home has actual fire or water damage, mold can start growing within 24 hours, so wet materials like drywall and flooring often need to be dried quickly or replaced, since drywall can hold moisture and grow mold on the hidden side even when it looks dry. When rebuilding, choosing low-VOC materials helps keep indoor air cleaner afterward, and getting your HVAC system checked and its filters changed before, during, and after cleanup matters too. Lingering smoke odor is stubborn and may need fresh paint, new flooring, deep cleaning, or HEPA vacuuming to fully clear.

For homes that just sit under a smoky sky without direct damage, checking a site like airnow.gov during air quality alerts tells you when outdoor conditions turn unhealthy. On those days, keeping windows and outdoor air intakes closed helps, and changing your HVAC filter often — upgrading to a MERV 13 rating if your system can handle it — improves filtering. An indoor air quality monitor that tracks particles and VOCs can also flag when your home's air needs attention.