Fire is natural and inevitable in the highly flammable brush communities that Southern Californians seem to insist on living near.
With the toll in this fall's Southland fires at more than 1,200 homes, it's time to rethink what we build and how we landscape, experts say.
We're going to have to make houses and gardens more fire-resistant, increasing the likelihood that they will survive the next big wildfire.
Experts say it can be done, and the precautions presented below are aimed at those who live right next to chaparral and coastal scrub, as well as those who live nearby.
The majority of houses catch fire from fire brands or flying embers, which can easily travel up to a half-mile from the actual flames.
It's important that when they land, there is nothing to ignite and no place to lodge. A fire-resistant house is clean and tight, "buttoned up" as one fire researcher put it. No detail is unimportant; natural fiber doormats have caught houses on fire.
Houses that actually abut wildlands, or are surrounded by them, must also be prepared for a frontal assault by the flames, and landscaping becomes important as a buffer.
The general idea is to create a "defensible space" 100 to 200 feet around a building. Wind-driven flames can easily extend 100 feet on a slope and reach temperatures of 2,000 degrees.
A fire-resistant landscape is more problematic than a fire-safe house, because of a number of clashing agendas. Plants are being asked to resist catching fire, hold the soil with their roots, not use too much water, provide shade and energy-saving cooling and not threaten the natural environment with their exoticism.
And the best plants for the job are the ones already growing there, the experts now say, in a remarkable turnaround from just a few years ago.
Researchers and fire department personnel now think that managing the existing chaparral or other plant communities is a better idea than trying to replace it with exotic, non-native plants.
"Nothing's better adapted to this climate and these soils," one expert said.
Sources: --Carl Day, AIA & Associates. --Dick Chase, retired, Riverside Fire Laboratory, Fire Management Project. --Michael Theule, Fire Inspector II, Los Angeles Fire Department, Brush Clearance Unit. --Klaus Radtke, Geo Safety Inc. --Owen E. Dell, landscape architect. --Tim Paysen, Research Forester, Riverside Fire Laboratory. --Bob Perry, landscape architect. --Walter Scott Perry, architect. --Marc Fisher, Emmet L. Wemple & Associates, landscape architects. --Harry Jacobs, FAIA, architect.
Home and Yard
Shutters: Fireproof shutters can be closed when fire threatens, to protect glass and interiors in areas that abut wildlands. Removable panels are another means.
Access for firefighters: Leave access and turnaround space for firefighters and fire trucks, as approved by fire department, to get to back and sides of house. In remote areas this is extremely critical.
Eaves: Best are none at all, and no wood fascia. Boxed eaves are next best, the underside covered with fire-resistant material.
Garage door should shut tight: A house burned in one brush fire because the garage door wouldn't close all the way. Roll-down metal doors close tightly.
Vents: After the Oakland fire all vents under overhangs or eaves of roofs were banned in that city. Vents should be on rooftop (such as ridge vents) or in gables. Roof and foundation vents should be screened with one-quarter inch galvanized mesh.
Set back from slope: Fires race up hillsides, so houses should be as far back from the slope as possible, with nothing overhanging the hill.
No wood fences: They act like fuses, leading fire to the house. Masonry walls, on the other hand, even low ones, can actually deflect heat and flames (and keep rattlesnakes out).
Step-back construction: Avoid single, high-walled construction. Step tall buildings back from slope.
No "pyrophytes": Certain plants are almost explosive, especially when dry. Junipers, one of the worst, are disastrous when planted under eaves. Do not plant any conifers, including pines and cedars, dense eucalyptus, peppers, bamboo, pampas grass or palms.
Roof: It's hard to believe that any shingle or shake roof still exists in fire areas. Definitely must be non-combustible with no gaps or places for embers to lodge. Curved spanish tiles must have open ends plugged.
Siding: Non-combustible stucco or stucco over cement building panels in areas that abut wildlands.
10-foot minimum clearance: Many say this is the most important rule. No tree or tall shrub should be within 10 feet of the house. (Fire departments would prefer 30 feet.) This alone reduces the heat at the house walls by a factor of four.
Double-glazed windows: Research is proving that double-glazed windows are much less likely to burst when confronted with fire, and little radiant heat can pass through. Behind conventional windows, consider drapes of fireproof fabrics.
No nooks and crannies: There shouldn't be any place on the house where embers or fire brands can lodge or collect.
Swimming pools: If you have a pool, provide access for firefighters (so they can pump from it) and consider your own gas or diesel-powered pump, plus hose, for ember dousing.
No wood decks, maybe overheads: It's best to avoid wood decks, even at ground level or with their base completely enclosed. Decks of fire-proof materials are OK. Be sure the support beams and columns are also protected. The jury is out on patio overheads, if they are open (so firebrands can pass through), made of heavy timbers and do not touch house.
Yearly maintenance: Once a year (June is a good month), cut back weedy annual grasses and prune and clean up dead wood that accumulates in and under plantings. You cannot walk away and forget fire-resistant landscapes or they will soon grow to become woody and dangerous.
Greenbelts: One of the more interesting new ideas is that native coast live oaks might make a good greenbelt around properties or subdivisions. They resist fire and drought, have hill-holding root systems and provide habitat for a wide variety of wildlife. Are they the perfect buffer for the chaparral/urban interface?
One way of looking at a landscape in fire-prone areas: Divide the property into zones of increasing safety, as plants approach the house, decrease height and volume the closer they are.
One professional said, "It's not the plants themselves so much as the arrangement of plants," the idea being to eliminate "fire ladders" to the house. Another observed that "some trees and overhanging vegetation can be more flammable than the native vegetation." Keep things away from the house.
Zone 1 (0-30 feet from house): Irrigated garden of mostly low-growing plants and lawn. No plants under eaves (if any) and no tall plants closer than 10 feet from house. If it is irrigated regularly, and there are fire-resistant plantings further from the house, you can grow just about anything here.
Zone 2 (30-60 feet from house): A greenbelt or living firebreak of the most fire-resistant or fire-retardant plantings, such as rosea or white trailing iceplant, cape weed, snow-in-summer, ivy, geraniums, yarrow, dwarf rosemary, Myoporum parvifolium or the native Ceanothus griseus horizontalis or C. prostratus occidentalis . Several handsome, fire-resistant trees are live oak, western redbud, strawberry tree, toyon, mountain mahogany and carob.
Between Zone 2 and 3 is a good place to try to block fire with deep plantings of particularly fire-resistant plants, such as citrus, oleanders or native live oaks (but not scrub oak). Some experts believe these three have actually stopped fires in their tracks.
Zone 3 (60-100 feet from house): There's some debate over what can go here, and topography and relative fire-safeness of the house influence the choices. Some say only "knee-high" native and non-native plants that contain little fuel, such as low ceanothus, native monkey flower, bush morning glory, fuchsia-flowering gooseberry, dwarf strawberry tree, white rockrose, photinia, dwarf California coffeeberry, mixed with any of the low-growing ground covers. Try for drought tolerance because you really don't want to water all this with the price of water what it is. Others feel that Zone 3 should be like 4, and as much native vegetation should be preserved as possible.
Zone 4 (100-200 feet from house, up to 400 feet on north or east slopes): Selectively save native vegetation, while removing the most combustible. Get rid of all "soft" chaparral, especially chamisa, buckwheat and sage. Try to preserve a continuous canopy of foliage (to prevent erosion), but remove all dead material ("fine, dead, aerial fuel") from inside the plants.
Remove branches from the bottom third of plant. On steep hillsides, consult with an engineer or landscape architect or serious erosion can occur. Since properties are seldom large enough, this might have to be a community effort. Anything that grows back between or under plantings should be cut to 3 inches tall when it turns brown.