Keith is a broker associate with Compass.

In the Santa Cruz Mountains, the most dangerous part of a wildfire may arrive miles ahead of the flames. When most of us picture a wildfire destroying a home, we imagine a wall of flame roaring through the trees and crashing into the building. That can happen. But that is not how most homes ignite.

In recent California wildfires, 90 percent or more of the homes destroyed were ignited by embers. Those embers—small pieces of burning wood, bark, leaves and other material—can travel two miles or more ahead of the fire. They arrive by the thousands or millions, driven into neighborhoods by powerful winds.

I saw this firsthand during the 2020 CZU fire. My family was packing to evacuate our home as gray ash fell through a yellow-brown sky. Mixed into the ash were larger black fragments, some glowing orange inside. The flames were nearly two miles uphill, across Highway 17 and two county roads. Yet, here were dozens of burning embers dropping out of the sky.

We were lucky. Those embers landed on solid decking, leaving them pocked with dozens of black ember scars. Had they settled into dry leaves, bark mulch, or a debris-filled gutter, the outcome could have been very different.

A home ignites when heat, fuel, and oxygen come together. We cannot remove oxygen from the air or stop every ember carried by a wildfire. But we can remove the fuel an ember needs and interrupt the pathways that let a tiny ignition grow into a house fire.

Look at your home through an ember’s eyes. Can they settle in leafy debris? Can they enter your attic or crawl-space vents? Maybe wood mulch touches wood siding in a protected corner? Does a wooden fence connect directly to the house, creating a combustion pathway? Are there gaps around the garage door where fire-driven winds can blow embers inside?

Embers are only one threat. Direct flames from a burning shrub, fence, or shed can touch the home. Radiant heat from a nearby structure can break windows and heat other materials to ignition temperature. These pathways often work together: an ember ignites mulch, the mulch produces flame, and the flame climbs combustible siding under an open eave.

A stucco exterior or Class A roof does not make a home invulnerable. Neither does clearing brush while ignoring vents, gutters, decks, and roof edges. Wildfire searches for weak links. The encouraging part is that some of the most valuable work is simple: clean debris, move combustible storage, separate fuels from the house, and protect vents and other openings before fire season.

Home hardening is not about guaranteeing survival. It is about denying embers the small opportunities they need to ignite pathways into your home. Dave's book is available at amazon.com/dp/B0HGDLQKP8.