Wildfire smoke cleanup in Mountain Shadows

The Waldo Canyon Fire started on June 23, 2012, in the national forest west of the city. Three days later, erratic winds drove it over the ridges into Mountain Shadows, Peregrine and Oak Valley Ranch. Houses burned from embers and from each other rather than from a single wall of flame. By the time the fire was contained, it had burned 18,247 acres and destroyed 346 homes, and more than 32,000 people had been evacuated.

For every house that burned, many more were exposed. Smoke and ash drifted into attics through vents, into living spaces through gaps around doors and windows, and into ductwork through furnace intakes. Gas was shut off to about 4,200 undamaged homes. When residents returned, the work was mostly cleaning: filters, ducts, fabrics, attics and garages. That is the core of wildfire smoke damage cleanup.

The EPA's guidance comes down to one rule: capture ash, do not move it. That means no dry sweeping, no leaf blowers and no ordinary vacuums, which blow fine particles out of the exhaust. Use a HEPA vacuum indoors, mist decks and patios lightly before sweeping, and damp-wipe hard surfaces with a mild cleaner, changing the water often. Wear a fitted N95 respirator, gloves and long sleeves, and keep children and pets away from the work.

Fabrics usually hold most of the smell. Wash curtains, bedding and clothing in batches and send delicate items to a specialist cleaner. If ash reached the blower or returns, have the ducts cleaned before you rely on the furnace. Attic insulation with a visible layer of ash is usually removed and replaced.

Fuel has been building again on the slopes above Mountain Shadows since 2012. The city's wildfire mitigation unit and risk map are the place to start for your address. Fine metal mesh over attic and crawlspace vents keeps out embers and much of the ash; good weatherstripping and a closed fireplace damper help too. Keep spare high-efficiency furnace filters and a portable HEPA cleaner for a bedroom you can use as a clean room. NIST's work on wildland-urban interface fires found embers to be a major way houses ignite, so clearing debris from gutters, decks and the ground near the house also matters.

In 2012, many homes that survived stood beside lots where houses had burned to the foundation. Those survivors usually had more than smoke damage: heat-cracked windows, melted vinyl and vent covers, scorched siding and fences on the side facing the fire, and heavy ash from the burned structure, which can contain residues from building materials and contents rather than just vegetation. That calls for more caution during cleanup and more exterior repair afterward.

Photograph the fire-facing side of the house carefully, keep children and pets away from ash from burned buildings, and leave heavy deposits to a crew with protective equipment.

Fine particles from wildfire smoke and ash can aggravate asthma, COPD and heart disease, and children breathe more air for their size. While ash is being cleaned up, it is sensible for sensitive family members to stay with friends or relatives, or at least to stay in a closed bedroom with a portable HEPA cleaner running.