Wildfire embers and security screens, honestly

Wildfire is the one subject where we most want to out-boring the industry. You will find security screen vendors implying their mesh fireproofs a house. This page does the opposite: it lays out what is verified, cites where each fact comes from, and says plainly where our product does not belong in your fire planning.

What changed in the 2025 maps

CAL FIRE's updated Fire Hazard Severity Zone maps for Orange County, released March 24, 2025, are the first comprehensive revision in years, and they reach further into town than the old ones. Five cities appear in the mapping for the first time: Buena Park, Costa Mesa, Huntington Beach, Laguna Hills, and Placentia. Laguna Beach now counts about 87% of its land area in the Very High zone. Yorba Linda has more than 4,700 acres in Very High, its first full revision since 2007. Anaheim added roughly 300 acres at its eastern edge, in the Anaheim Hills area. The county adopted the unincorporated-area maps in August 2025.

None of this is a reason to panic, and we are not going to use it as one. It is a reason to know your own address's zone - the CAL FIRE zone viewer answers that in about a minute - because the zone determines which building rules apply to your home.

What the code actually requires

California's wildfire construction rules live in Chapter 7A of the Building Code, mirrored for houses as Residential Code section R337. As of July 2026, here is where ember protection is actually mandated, opening by opening:

Read the table twice and one fact stands out: screen doors and window screens appear nowhere in it. The chapter's full text is public on UpCodes if you want the primary source, and your building department has the final word for your parcel.

What fine metal mesh genuinely does

Outside the code, home-hardening research does give metal screens real, modest credit. Fire Safe Marin notes that fine mesh of at least 1/16 inch helps resist the entry of embers, that screens improved the performance of window glass exposed to radiant heat in testing, and - the honest other half - that windblown embers can still pass through screening, arriving with minimal energy, and that screens add no protection from direct flame contact. CAL FIRE's hardening guidance recommends metal mesh on operable windows and warns against fiberglass and plastic mesh, which can melt. The IBHS Wildfire Prepared Home standard, updated for 2025, mandates fine ember mesh at vents and under decks and gives screen doors no credit at all. That is the entire honest picture, and we are comfortable inside it.

Smoke is a different problem than embers

The two words travel together in every fire-season conversation, and conflating them is the most common mistake we hear at the door. An ember is a physical burning particle, often large enough that fine metal mesh obstructs it, which is the entire basis of the vent rule above. Smoke is gas and microscopic particulate. It moves through woven mesh exactly as air moves through it, because that is what woven mesh is for. No security screen filters smoke, ours included, and any screen sold on that basis is being sold dishonestly.

The practical consequence is a seasonal one worth planning around rather than worrying about. On a smoky day the answer has nothing to do with your doors: close the house up, run indoor filtration, and go by your local air quality reading rather than by how the sky looks, because the sky is a poor instrument. On the far more common clear night, the door does the job it was bought for. Treating those as two different modes of the same house is the honest version: open when the air is good, shut when it is not, and never confusing the screen for a filter in either direction. The cooling side of that rhythm, marine layer and all, is in our Orange County night-cooling guide.

Where that leaves our doors

A Daylight Steel door is a security product. The mesh is woven 316 stainless steel - noncombustible metal that does not melt away like fiberglass insect screen - and that is a genuinely better material to have standing at an opening. It carries no fire rating, no WUI listing, and no ember certification, so we make no fire promises. If your address sits in a mapped zone, spend your hardening money in the order CAL FIRE's own low-cost retrofit list suggests: ember-resistant vents, a chimney spark arrestor, cleared gutters, defensible space. Then buy a security screen door for what it is actually for - the open-door evenings, the locked mesh between your family and the street, and bedroom windows that still open for escape, which matters in every emergency, fire included.