Architects caution against misinformation about fire-safe rebuilding
ASHLAND — As post-Almeda fire rebuilding proceeds, Oregon representatives with the American Institute of Architects are keeping an eye out for misinformation that could confuse or mislead homeowners as far as what materials should structure their new homes.
In a public letter issued Nov. 24, AIA Southern Oregon members cautioned that skewed information could seep into “well-intentioned revisions of the local building and zoning codes, unreasonably limiting our rebuilding options and adding unnecessary costs to the process.”
Since the Sept. 8 Almeda fire, some have proposed using wood alternatives such as steel, concrete or stucco, to build fire-resistant homes. But a fire safe house isn’t necessarily wood free, according to AIASO.
Using exterior fire-resistant materials and establishing noncombustible zones around buildings have been defined as top priorities for reducing the impact of wildfire on residences, but home hardening strategies aren’t one-size-fits-all, AIA Oregon Executive Vice President Curt Wilson said.
“While using steel or concrete and metal roofing could work, this approach is most certainly not the only solution to the problem, nor is it a complete solution,” he wrote in the letter. “Also, there are other potentially far less expensive and less environmentally problematic approaches.”
Wood-framed structures can be adequately fire resistive using rated wall assemblies and doors, sheathing, gypsum board products, screening vents and gutters, and fire retardant-treated wood or plywood, Wilson said. Metal roofing is a solid option, but other low flame spread rated roofing products work as well.
Rated wall and roof assemblies are those that have been tested and proven to delay fire progression. The Federal Emergency Management Agency recommends at least a one-hour wall assembly fire resistance rating in its “Home Builder’s Guide to Construction in Wildfire Zones.”
Emergency rooftop sprinklers are an option, Wilson said, except most of the area affected by the Almeda fire was without power to operate well pumps and pressurized water systems.
Still, with the appropriate design, gravity-fed residential sprinkler systems could viably cover fire-prone exterior areas, he said.
Existing building codes are based on the premise that fires start within a building, grow and spread — the goal being to delay the fire until occupants can get out, Wilson explained.
“Most of the code language related to fires — the way that fire behaves — is generally based on that context of a fire inside the building,” Wilson said. “As more catastrophic fires are getting closer to urbanized areas ... the idea of how we protect buildings from fires is fundamentally different.”
Urban wildfires pushed by high winds and hot temperatures through dry conditions impose a new set of considerations for architects and builders.
Using rated assemblies on the exterior of a home may be uncommon, but a necessary consideration going forward, Wilson said.
“We can achieve fire resistance with materials other than steel and concrete — and at the same cost or often less expensive than what steel and concrete would be,” said Andrew Owen, architect and AIASO section director.
In addition, achieving fire resistance goes beyond the bricks and mortar, according to FEMA. In addition to guidelines for wall, door and window assembly fire ratings, the agency’s recommendations include creating defensible space around structures, installing utility connections underground, installing interior and exterior fire sprinkler systems, using noncombustible fencing materials, and using leaf guards in gutters.
A developer will build to the most cost-effective price possible while adhering to code, Owen said. Wood, steel and concrete buildings all have appropriate applications. Overall, AIASO wants homeowners to understand their options, he said.
Homeowners can avoid being taken advantage of by checking their contractor’s state license and asking around about the quality of their work, Owen added.
Recent wildfires revealed how elements of Northwest architectural style may require a redesign to accomplish a fire-resistant product in line with FEMA’s construction recommendations, he said. For example, large overhangs that protect from rain and sun — historically characteristic of the area — also help fire to accumulate and accelerate.
“Primarily, when we’ve been using the term ‘resiliency,’ we’ve really been talking about preparing for and being ready for the next big earthquake,” Wilson said. “But what wildfires are showing us is that there’s a lot of different events that we have to think about and prepare for.”
Contact Ashland Tidings reporter Allayana Darrow at firstname.lastname@example.org and follow her on Twitter @AllayanaD.