Wildfire Preparedness: Defensible Space, Smoke, and Evacuation

Most households affected by a wildfire never see one. They see a week of hazardous air, a school closure, a relative with asthma who can't go outside, and a grocery run that gets complicated. Smoke routinely travels hundreds of miles from a burn perimeter, which means the number of households that need a wildfire plan is far larger than the number in a fire's path.

That is worth saying plainly because it changes what preparing means. If you live in a high-risk county, defensible space and evacuation come first. If you don't, masks and air filtration cover most of your realistic exposure — and that is a much smaller job than the wildfire conversation usually implies.

562 of 3,135 US counties carry wildfire among their leading FEMA hazards. You can check where your county ranks.

If you are in a high-risk area, this is the single highest-impact thing you can do, and it is the one insurers increasingly ask about. The principle is simple: fire needs fuel, and you are removing fuel from the ground immediately around your structures.

• 0–5 feet: nothing flammable. No bark mulch, no firewood stacks, no shrubs against siding, no doormat you'd miss. Gravel or bare soil.
• 5–30 feet: mown grass, well-spaced plants, no “ladder fuel” that lets a ground fire climb into tree canopy. Prune branches up to 6–10 feet.
• Gutters and roof valleys: clear them before dry season. Wind-carried embers landing in dry leaf litter start more house fires than an advancing flame front does.
• Vents: 1/8-inch metal mesh over attic and crawlspace vents. Embers get in through openings you never think about.

The most common evacuation failure is a household that knows exactly one way out. Fire closes roads unpredictably, and it closes them in the direction the wind is going — which is often the direction you planned to drive.

Identify a second route, ideally heading a different compass direction, and drive it once so it is familiar in the dark. Note which roads flood or close seasonally. If you have livestock or animals that need transport, the second route needs to work for a trailer too.

Leave early rather than correctly. Evacuation orders are issued with the assumption that everyone leaves at once, and the roads are sized for ordinary traffic.

• N95 or P100 masks — fitted, per person. Cloth and surgical masks do nothing for fine particulate. Children need child-sized ones; adult masks do not seal on a small face.
• One clean room — pick the room with fewest windows, run a HEPA purifier sized for it, keep the door shut. You do not need to filter the whole house.
• A DIY box-fan filter — a MERV-13 furnace filter taped to a box fan is a legitimate substitute and costs a fraction of a purifier.
• Close the fresh-air intake on HVAC systems and switch to recirculate.

Photograph every room, including inside closets and cupboards, and store it somewhere that is not your house. Claims are settled on what you can document, and nobody makes a home inventory during an evacuation warning.

Check two things in your policy before fire season: whether wildfire is covered at all, and what the deductible is. In high-risk counties both have been changing, and finding out at claim time is the expensive way to learn.

Ordered by how much risk each removes. Do them in this order and stop whenever you run out of time — the first three cover most of it.

1. Clear gutters and the 5 feet immediately around your walls
2. Buy fitted N95s for everyone in the household
3. Drive your second evacuation route once
4. Photograph your home's contents
5. Pack go-bags and leave them packed through the season