In a high fire severity zone the roof needs a Class A assembly and ember resistant vents.
At a glance
- Class A is the top fire rating and most modern roofs reach it.
- Embers, not flames, start most house fires in a wildfire.
- Vents and gutters are the weak points, not the roof field.
- Chapter 7A products are the standard in the fire zones.
What the ratings mean
Class A resists severe fire exposure. Class B is moderate and Class C is light. The rating belongs to the whole assembly, not just the top layer, so a covering can earn Class A only when it sits on the tested underlayment and deck.
Tile, metal, most modern shingles and single ply systems reach Class A. Untreated wood shake does not.
Where embers get in
Wind carried embers land in gutters full of leaves, blow into open eave vents, and pile in the gap under the first course of tile. Any one of those can start a fire while the flame front is still a mile away.
Ember resistant vents with fine mesh, bird stops at the eave course of tile, and clean gutters take away most of that risk.
The Los Angeles County picture
Large parts of the county sit in a Very High Fire Hazard Severity Zone. That includes the hills above Altadena, the Verdugos, the Santa Monica Mountains, Malibu, Topanga, the Santa Clarita hills and much of the Angeles foothills.
Homes in those zones fall under the state Chapter 7A rules for exterior materials, and insurers have their own lists on top of that.
What to do this season
Clear the gutters and the roof valleys of needles. Check that every vent has intact metal mesh. Trim branches back from the roof edge. Fill the gap under the first tile course with a proper bird stop rather than mortar crumbs.
None of that is expensive and all of it is what post fire reviews keep finding.
Common questions
Do I have to reroof if I live in a fire zone
Not because of the zone alone. New work has to meet the rules, and insurers may ask about the material.
Is tile fireproof
Tile does not burn, but embers can enter the open ends. Bird stops close that path.
Will a Class A roof lower my insurance
It can help, and in some fire zones it is a condition of getting covered at all.