Author: Nina Olivier, Built Green Coordinator

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:
• OSHA: Wildfire-related Quick Cards
• CDC: Preparing and Staying Safe During Wildfires
• CDC-NIOSH: Outdoor Workers Exposed to Wildfire Smoke
• U.S. Department of Agriculture: Decision Making for Wildfires
• FEMA: Prepare Your Organization for a Wildfire Playbook

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

Author: Nina Olivier, Built Green Coordinator

By September 2020, wildfires had burned over 713,000 acres in the State of Washington, resulting in the loss of 181 homes and one fatality. Research conducted by the National Fire Protection Association concluded that wildfire embers and smaller flames were the main ignition source of homes.

Along with the destructive risks associated with wildfires, exposure to the particulate matter in its smoke also poses a significant health risk. According to the University of Washington's Department of Environmental and Occupational Health Sciences, breathing in the fine particulate matter from wildfire smoke, known as PM2.5, can contribute to respiratory, cardiovascular, and other health problems and even lead to premature death.

Built Green recognizes the importance of providing healthy indoor air and fire safe homes for all those living in Built Green certified homes. As a result, there are numerous checklist credits dedicated to decreasing the number of pollutants and providing means for air filtration during wildfire smoke season as well as methods to minimize the likelihood of flames or surface fire touching the home or any attachments.

Below is a list of preventative actions you can take to protect your family and your home during the annual wildfire season.

Roofs and Gutters

Strategies to limit your home's ability to act as a fuel source include:

• Clean roofs and gutters of dead leaves, debris and pine needles that could ignite from air-borne embers.
• Replace or repair any loose or missing shingles or roof tiles to prevent ember penetration.
• If you are replacing your roof, install a Class A slate or metal roof.
• Install 1/8-inch metal mesh screening to reduce embers that could pass through vents in the eaves and attics.

Windows and Doors

• Ensure all windows and doors are closed and tightly sealed to reduce the infiltration of smoke and embers in your home.
• Install weather stripping to increase air tightness during smoke events.
• Do not use portable air conditioners that use a single hose exhausted out a window which will bring more smoke inside.
• Have a portable air conditioner with two hoses? Make sure that the seal between the window vent kit and the window is as tight as possible through adhesive-backed foam tape, felt, EPDM rubber weather seal tape, and vinyl strips.
• Once air quality improves, air out your home by opening windows or the fresh air intake on your HVAC system.
• If you are retrofitting the siding of your home, consider installing fire resistant exterior siding such as three-coat stucco, metal siding, and fiber cement siding.

Indoor Air Quality

• Invest in a high quality portable air cleaner as recommended by the EPA.
• Upgrade the air filter in your furnace or central heating, ventilation, and air-conditioning (HVAC) systems and use them to recirculate and filter the air inside your home.
• Attach a MERV 13 or FPR 10 filter to the back of a box fan to create an additional air filter.
• Increase your home's humidity to help remove small particulate matter in the air using portable humidifiers.
• Avoid activities that create fine particles indoors such as smoking, cooking, burning candles, and spraying aerosol products.

Decks and Porches

• Treat existing wood decks against fire with a flame retardant spray; do not replace them with endangered tropical woods like Ipe or ironwood.
• Add metal sheathing around the base timbers.
• Replace any decaying timber boards.
• Install metal screening around the crawlspace beneath the deck to keep fire embers out.
• Consider building a deck with composite materials with Class A or B fire ratings, but avoid composites that contain PVC, which produce very toxic fumes when they burn.
• Remove anything stored underneath decks or porches.
• Store away all furniture cushions, mats, potted plants, and decorations to avoid them catching embers and igniting.
• Remove the deck as a source of ignition by instead building a stone, paver, or concrete patio.

Landscaping

• Map out your home's ignition zones and take actions to decrease the ignition risks in the immediate ignition zone that directly increase the likelihood of flames touching your home.
• Establish defensible spaces that are maintained and designed to slow the spread of fire to and from the building, and create fire buffers around the house.
• Plant native species that are fire resistant
• Remove dry underbrush and unhealthy vegetation and trees.
• Mow tall or dry grass areas and discard the clippings.
• Trim back tree limbs that hang over or encroach on your home's immediate ignition zone and deck.
• Move any flammable material away from exterior walls – mulch, flammable plants, leaves and needles, firewood piles, grill, or fire pit propane tanks – anything that can ignite or combust.

Be Prepared

In an event of an evacuation, understand and map out a safe evacuation route from your region. Prepare an emergency kit including a supply of N95 or P100 masks, water, flashlights, and first aid essentials. Continue monitoring https://www.airnow.gov/ and https://www.dnr.wa.gov/Wildfires to monitor your region's smoke index and wildfire locations.

More information can be found on the National Fire Protection Association's Website.

Diagrams produced by National Fire Protection Association and Colorado State University

With a specific focus on indoor air quality, this home employs a new ventilation and air filtration system, helping to make it a safe and comfortable environment for its occupants. The state-of-the-art fresh air system includes a Zehnder 350 HRV, Zehnder ComfoPost inline heating/cooling coil, and HEPA air filtration system. This system allows for fresh, filtered air to enter the home throughout the day and to be increased when needed, such as when the kitchen hood fan is drawing smoke out of the kitchen during cooking. This fresh air system maintains high indoor air quality by reducing particulates in the air, even when the outdoor air quality is particularly poor, such as during a summer forest fire.

Built with passive and active solar needs in mind, this two-story house faces south. Triple-paned Vinvltek windows on the south side provide passive heating and natural light within the home. White interior paint also helps provide significant daylighting and reduces energy demand from the home’s LED lighting.

The home also employs a 12.87kW photovoltaic system, producing enough power to make the home net positive and power an electric vehicle. With a shell system constructed from 6.5” SIPs walls, 10.25” SIPs roof, 4” foam under the slab-on-grade, ICF form slab-edge stemwalls, and U 0.18 average triple pane windows, this house has a tight envelope, helping to reduce energy consumption.

The three-bedroom, two bath house is meant to allow the occupants to age in place. The first floor has a kitchen, main living space, a bedroom and bathroom, and ADA-compliant doorways.

Overall, this home is a comfortable, clean, net positive building, allowing the homeowners to be happy, healthy, and confident in the knowledge that their home is serving their needs, meets a high standard of excellence, and is protecting the environment in the process.