Pro dealer Augie Venezia, president of California-based Fairfax Lumber & Hardware, says the days of waltzing into a building permit department and expecting to get quick approval on your plans are gone, at least in California. That all changed on Jan. 1, 2008, when California implemented requirements for building materials used in the exterior design and construction of buildings within Wildland-Urban Interface (WUI) fire areas.
Under Chapter 7A of the California Building Code, lumber products used as siding, decking or soffits in exteriors must pass state-mandated fire tests. Much of California falls within the WUI, and disaster awareness is spurring a careful examination of building practices, ranging from landscaping guidelines to the performance of building components when subjected to exterior fires.
“Substantial changes to the building code will eliminate the weak spots in typical home construction that allow fire, heat and embers into a building,” said Kate Dargan, the State Fire Marshal. “Buildings that are protected against embers can better withstand a wildland fire.”
What that means to manufacturers and builders is more scrutiny. What that means to dealers is still uncertain, but there is opportunity to upsell profitable products like tempered windows and fire-resistant decks and siding.
The new standards cover windows, roofing and siding, gutters and eaves, and the materials used in the assembly and construction of these products. “The fire marshal will want to see some real detailed plans before giving any go-ahead,” Venezia said.
Since January, 25 companies have received certification for their products. Despite some early logjams in the certification approval process, companies contacted who have received approval said the process went smoothly. Approved wood products include those made from Western Red Cedar, Port Orford Cedar, Incense Cedar, Alaska Yellow Cedar, Redwood, Ponderosa Pine, Douglas Fir, White Fir and Western Spruce.
“There is opportunity for those who go through their standards testing and get on the list of approved products. That will set them apart from competitors,” said Ken Dunham, executive director of the Lumber Association of California and Nevada, which represents 275 dealers.
From a profit standpoint, Venezia said he hasn’t seen any meaningful change yet. However, the new building standards affect a vast majority of the state, in terms of both methods of construction and types of materials. “It’s just a new way of thinking,” Venezia said. “We’ve always had products that are fire resistant or didn’t burn, but the only difference now is that they have to be tested in the assembly in which they will be used.”
Some product categories will see more changes than others.
When it comes to wildfires, the roof is the most vulnerable part of the house. Ignition-resistant “Class A” and non-combustible roofs—such as concrete tile and asphalt composition shingles—have become the norm in California due to laws passed in the late 1990s that required all new homes and all roof replacements in very high fire hazard severity zones to be Class A. Nevertheless, there are still many older homes that do not have Class A roofs.
Vents for crawl spaces under homes or for attics are required by most building codes to prevent a build-up of moisture, which can lead to mold growth and decay in building materials. Embers that slip through attic vents can ignite debris and items stored there, and subsequently construction materials, setting the home ablaze from within. “Most of the damage in fires is from wind-blown embers, and they can easily get into vents,” Venezia said.
The importance of vents in wildfire resistance is leading to such innovations as the development of vents specially designed to limit ember intrusion while still all owing sufficient air flow for ventilation and construction designs and procedures that permit unvented attics to avoid moisture-related problems.
Research has shown that the most important factor in determining the vulnerability of windows in a wildfire is the glass, not the frame. The new building codes recommend dual-pane windows with tempered glass. With dual pane windows, the outer pane protects the inner pane. The inner pane heats up more slowly and uniformly, and therefore may not break even though the outer pane does.
Tempered glass is much stronger than regular glass (and more expensive), so it provides more protection from breaking. The new chapter in the building code requires at least one pane to be tempered glass. Since the type of frame doesn’t make much difference in a fire, it can be selected based on cost, aesthetics, energy efficiency or other factors.
Decks and siding
An ignited deck endangers many portions of a structure and is often adjacent to large windows or sliding glass doors. The heat from a burning deck can cause the glass to break and permit the fire to enter the house.
New decking products are hitting the market in the wake of the new building codes. Materials including plastic, plastic composite lumber, fireretardant treated lumber for exterior use, or lumber—that passes the state test procedure approved by the California State Fire Marshal’s office—are commercially available now or will be soon.
In research trials, good quality sheathing, which is installed underneath the siding, was a key to protecting the home’s studs, dealers said. A wide array of non-combustible siding can be installed over the sheathing—such as stucco or fibercement siding.
International Barrier Technology was the only company on the approved list to have a single product (Blazeguard) listed under three categories—exterior wall siding and sheathing, undereave and ignition-resistant materials. Blazeguard panels feature Pyrotite, a patented, cementitious coating over either oriented strand board or ply wood of various dimensions. The coating resists ignition and adds structural strength to its underlying substrate, according to the company.
What the code means
Many of the new changes reflect the findings of a report from the Institute for Business & Home Safety (IBHS) regarding the Witch Creek Wildfire, which damaged or destroyed nearly 1,700 structures in San Diego County in 2007, causing $1 billion in insured losses.
IBHS evaluated nearly 3,000 homes to determine why some survived and others did not, despite facing similar wildfire conditions. The study also analyzed meteorological conditions, vegetation and topography, building characteristics and social attitudes.
Homes situated less than 15 feet apart are at high risk, the study found. While homes adjacent to wildlands are most vulnerable, homes in the interior areas of neighborhoods that were located less than 15 feet apart were much more likely to burn in clusters.
Wind-blown embers caused the most damage to homes during Witch Creek Wildfire. In fact, there were few, if any, reports of homes burned as a result of direct contact with flames.
“Unlikefires in buildings, which start from the inside, a wildfire burns through an are a quickly and keeps going—it doesn’t stay there,” Venezia said. “A catastrophic loss can be minimized by spacing and construction methods. Materials that are slow to burn and basic maintenance, brush that is in gutters, hot, wind-blown embers going horizontal, those are the biggest issues to be dealt with.”
Dunham’s biggest issue with the new codes and testing are the methodology used. “Is it valid to put a blow torch to a piece of wood for 20 minutes?” he asked, a reference to one of the tests. “Wildfires don’t act like that. I am certainly no fire science guy, but that is not the way these fires burn. These fires jump. It’s not a concentrated burn.”
As part of the new standards, each property must maintain defensible space around its structure. Venezia said the landscaping issue could be the most contentious for homeowners because some cities in the state are going around and making homeowners remove trees that could be a fire hazard.
“Some of the cities are letting it slide while others are taking it seriously, maybe too heavy handed,” he said. “A tree on a property that is like an old friend might have to go, for example. Some of these trees are big and expensive to move.”
He said all juniper bushes, which are oily and ignite easily, will have to be removed from the defensible area. “Business hasn’t changed that much, but awareness has,” Venezia said.