Author: Nina Olivier, Built Green Coordinator
Between extreme heat and drought across the entire Western U.S. the annual
wildfire season has arrived early in the Pacific Northwest. Climatologists
warn that as climate change progresses this trend will continue into the
future with increased likelihood of longer and drier wildfire seasons.
During the construction phase of any project, there are strategies that can
be implemented to keep the build site and staff safe and healthy during
wildfire season.
Worker Safety
Naturally, outdoor workers – including those who respond to wildfires – are
most impacted, both directly (from the fires themselves) and indirectly
(from smoke and fine, airborne particles dispersed by the fires). The Washington State Department of Labor and Industries has approved an emergency rule to protect workers from wildfire smoke.
When it comes to protecting workers on job sites from hazards caused by
wildfires, there are several strategies employers can implement.
- Conduct a Toolbox Talk on wildfire and smoke safety for all onsite staff
- Reduce worker exposure:
- Stagger work shifts
- Reschedule outdoor work
- Modify tasks that require more exertion
- Offer more rest periods and breaks in areas with filtered air.
- Employers are required to provide N95 filtering facepiece respirators to workers on days when the local air quality index for PM2.5 is 151 or
higher, and when employers reasonably anticipate that workers could be
exposed to wildfire smoke. An air quality index reading above 150 is considered unhealthy, according to EPA.
- Have an evacuation plan in place to avoid worker injuries and confusion
should a wildfire escalate in severity. Some businesses are required to
have an emergency action plan under OSHA’s Means of Egress Standard (1910.38).
- Additional resources:
Preventing Damage During Construction
With the expansion of the Urban Growth Areas and residential construction
into previously undeveloped forests and wildlands, build sites are
increasingly at risk from wildfires. Known as wildland-urban interface areas (WUI), these areas are where houses are in, or near highly flammable
wildland vegetation.
There are fire prevention construction strategies builders can prioritize
in WUIs to prevent starting a wildfire and ensuring the safety of their
project and staff from risks associated with wildfires.
- Prepare a hazard and risk assessment to determine the wildfire fuels, weather, topography, assets at risk,
and the wildfire occurrence.
- Create a defensible space that acts as an area around a home in which vegetation, debris, and
other type of combustible fuels have been treated, cleared, or reduced.
- Ensure access roads and driveways are wide and strong enough to
accommodate emergency vehicles and provide access for necessary
firefighting efforts.
- Strictly enforcing no smoking policies
- Restrict the use of space heaters in high-risk areas
- Properly training workers on safe work practices and fire prevention
- Storing combustible materials away from buildings that are under
construction
- Placing fire extinguishers at individual work areas and ensuring workers
know how to operate them
- Avoid starting vehicles and heavy equipment on top of dry vegetation
Building Design
Addressing the impacts of wildfires and the smoke they produce in Built
Green projects during the design phase, rather than at the end, will go a
long way in providing better indoor air quality, protection and resiliency
from house fires, and higher value for buyers.
In fact, many insurance companies offer discounts and rebates to clients
with fire-safety features that have been pre-built and installed into the
building further increasing the home’s value.
- Select a development site that considers topographic features such as
slopes, canyons, local vegetation, and weather that influence wildfire
behavior.
- Keep garages detached from the main home as they are often ignition sites
that can impact the main housing unit.
- Exterior Walls:
- Use siding materials that are noncombustible or fire-resistant and not susceptible to melting are recommended such as three-coat stucco,
shale, metal, and fiber cement siding. A minimum fire-resistance rating of
1 hour for the wall assembly is recommended.
- Use structural insulated panels (SIPs) or Insulated Concrete Forms (ICFs) that have superior fire suppression properties to conventional stick frame
construction.
- Roof:
- Install Class A rated roof assemblies with noncombustible coverings using metal, slate, tile or clay.
- Install eaves with short overhangs and flat soffits with a minimum of a 1-hour fire
resistance rating.
- Install leaf guards over gutters to prevent leaf debris from collecting in the primary ignition
zone.
- Vents that are a minimum of 10 feet from property lines and other buildings,
constructed of metal products, and have corrosive-resistant metal mesh
screens are recommended.
- Windows and all other glazing should be fire rated or triple-pane with at least one layer of tempered
glass.
- Avoid materials containing PVC or Vinyl that produce toxic fumes when
they melt or burn that are dangerous to residents and firefighters.
- Decks:
- If building a wooden deck use exterior grade fire-retardant-treated wood lumber, do not use Ipe/Ironwood or any other endangered tropical wood
species. Add metal sheathing around the base timbers.
- If using a composite decking material specify a Class A or B fire rating,
but avoid composites that contain PVC, which produce very toxic fumes when
they burn.
- Install metal screening around the crawlspace beneath the deck to keep
fire embers out.
- Increase the defensible space of the home by building a stone, paver, or
concrete patio, instead of a deck.
- Fences and walls constructed of noncombustible materials such as concrete, stone, and
masonry are recommended. Attaching a fence or wall to the building
should be avoided unless the fence or wall is constructed of
noncombustible materials.
For more information visit FEMA’s website.
Diagrams produced by ICF Homes of Virginia and ReadyForWildfire.org