Dry leaves in a gutter are one of the easiest ways a wildfire gets into a house. Embers blow in ahead of the fire, land on the roof, roll into the gutter, and settle into a trough full of dry oak leaves and pine needles pressed against the wood fascia and the edge of the roof deck. It doesn’t take a flame front. A single ember in the right gutter is enough.
If you live in Porter Ranch, Topanga Canyon, Malibu, the Calabasas hills, the Tujunga foothills or anywhere else with chaparral within sight of the house, this is the guide to read before October.
Why are gutters such a problem in a wildfire?
Three things line up.
First, the gutter is the collection point for everything that dries out on the roof. By the end of summer, a gutter that hasn’t been cleaned since spring holds a season of leaves, needles, bark and seed pods that have baked at roof temperature for months. It’s tinder in a metal tray.
Second, that tray sits against the most flammable part of the exterior. The fascia board is wood. The roof sheathing behind the drip edge is wood. The eave above it is often open or vented. A fire that starts in the gutter has a direct path into the roof structure and the attic.
Third, embers are drawn to it. In a wind-driven fire, embers can travel a long way in front of the flames, sometimes a mile or more depending on the wind, and they land wherever the wind drops them. The roof is a big target. Everything that lands on the roof ends up in the gutter. Homes in wildfire areas are lost to ember ignition far more often than to direct flame contact, and gutters, vents and the ground right against the wall are the usual points of entry.
Which debris is worst?
All of it burns, but some burns easier.
Eucalyptus leaves and bark are full of oil. They ignite fast and burn hot, and the bark strips are shaped to catch wind. There’s a lot of eucalyptus in the Conejo Valley, the Santa Monica Mountains and around the older Valley neighborhoods.
Pine needles are thin, dry fast, and pack loosely with a lot of air between them, which is exactly what you want in kindling. The foothill neighborhoods in Tujunga, Sunland and Sylmar sit under pines and cedars.
Coast live oak leaves are small and waxy and they sit in the gutter for years without breaking down. On the oak lots in Calabasas, Hidden Hills, Agoura Hills and Bell Canyon, the gutters fill with a dense oak-leaf mat that dries hard in summer.
Palm fronds and the fibrous material at the base of palm trunks are among the worst for throwing embers and for catching them.
When should I clear gutters for fire season?
Before the wind, not during the warning.
Santa Ana wind season usually begins in October and runs into the winter. The most dangerous fire weather is a Santa Ana event after a long dry stretch, before the first real rain. That window, roughly October through early December, is when a red flag warning is most likely and when your gutters are at their driest and fullest.
So the cleaning should happen in late September or early October. That gets the summer buildup out ahead of the first wind event. Then, because a strong Santa Ana refills gutters with fresh debris in a day, check them again after any big wind event and before the next warning. In a bad year that can mean two or three visits in the fall.
Don’t schedule this for the day a red flag warning is issued. Everyone else calls that day too, and we won’t put a technician on a ladder in 40 mile per hour gusts. Ladder work in wind is a hard no, and we cover why in the safety guide.
The good news is that a fall gutter cleaning does double duty. It’s the same visit you need before the rainy season anyway. The pre-rain checklist covers what else to look at while you’re up there.
Do gutter guards help or hurt?
It depends entirely on the material.
Metal guards help. A stainless micro-mesh or aluminum screen guard keeps leaves, needles and fronds out of the trough. An ember that lands on a clean metal guard has nothing to ignite. The trough underneath stays mostly empty. That’s a real reduction in ember exposure at the roof edge.
Plastic and vinyl guards hurt. They’re fuel. Plastic screens, foam inserts and vinyl snap-in covers melt and burn, and a foam insert that’s been holding damp debris all winter is full of dried organic matter by fall. If your house has plastic guards and you’re in a hillside neighborhood, replacing them with metal is one of the better fire-hardening upgrades available for the money.
Any guard, metal or not, needs the surface kept clear. Debris sitting on top of a mesh guard burns just like debris in an open gutter. Guards cut the volume of fuel. They don’t remove the need for a fall visit. Our guard guide goes through the types.
What about the gutter material itself?
Aluminum and galvanized steel gutters don’t burn, but aluminum does soften and can deform in intense heat. Vinyl gutters melt and burn. If your house still has vinyl gutters and you’re in a high fire hazard area, that’s a replacement worth talking about, and the options are on our products page.
Downspouts matter too. A downspout packed with dry needles is a vertical fuse running down the side of the house. Flushing downspouts is part of every cleaning we do, and it’s especially relevant here.
How does this fit with defensible space?
Fire agencies in California talk about defensible space in zones out from the house. The zone that matters most for gutters is the one right against the structure, the first few feet out from the walls, which Cal Fire refers to as Zone 0 or the ember-resistant zone. The general guidance for that zone is that nothing in it should be able to burn: no bark mulch against the wall, no dead plants, no firewood, no debris on the roof or in the gutters, and vents screened against embers.
Gutters are inside that zone by definition. They’re attached to the house. Clearing them is the same category of task as raking the mulch away from the stucco and pulling dead branches off the roof.
Insurance companies in the region have started asking about this kind of thing, and some inspect for it. We’re not going to tell you what your insurer wants, but clean gutters, metal guards and clear roof edges are on most of the checklists we’ve seen homeowners get.
What we do on a fire-prep visit
A fall cleaning in a hillside neighborhood covers the gutters, the downspouts, the tile roof valleys, and the roof surface near the gutter line where debris collects behind chimneys and against walls. We pull fronds and branches that are lying on the roof. We check that guards are seated and clear. We flush every downspout so there’s nothing packed inside. We use a gutter vacuum wherever we can, so the dry debris goes into the vacuum instead of being scattered around the house. Then we tell you what we saw, including anything on the roof or around the eaves that looked like a problem.
If you’re in a neighborhood with ember exposure, the membership plans let you lock in a fall visit every year so it happens before the wind, not after the warning. Joining is free, and the more frequent plans cost less per visit.
To get on the calendar before the season, call (818) 913-1626 Monday through Saturday 7am to 7pm, or request an estimate. We cover the hillside neighborhoods from Bell Canyon to the Malibu coast, and you can see every area we serve.