“I received a notice from the Fire Department that said to cover my woodpile with fire-resistant materials. What is that?”
The law (14 CCR § 1299.03) states that exposed firewood within 30 feet of structures should be covered by a “fire resistive material”, but does not specify what materials comply. To best protect firewood from ignition by embers, it should be moved inside a well-sealed, protected structure (for example, a “hardened” garage or shed with defensible space space around it, sealed doors, and screened vents). If this is not an option, move the pile at least 30 feet from any structure and cover with a tarp that complies with, at a minimum, the NFPA 701 Method 2 standard. Typical “poly” tarps available at a hardware store are not adequate, as embers may burn/melt through them.
While we don’t have a specific recommendation for a vendor or brand of tarps, this may be a good place to start.
A tarp covering must be securely fastened, to prevent embers from finding their way to the woodpile even during the strong winds associated with wildfires. Also, be sure to check the tarp’s integrity annually – long term performance when exposed to UV is unknown and may vary from product to product.
Don’t forget that this code also requires all exposed woodpiles to have a minimum of ten feet (10 ft.) of clearance, down to bare mineral soil, in all directions.
It’s worth noting that this code, passed at the state level, is based on decades of firefighter observations of home ignitions during wildfires as a result of woodpiles.