Firewood Requirements - June 1 through September 30th
Fire resistive tarps or covers are required if 30 feet or more of clearance from the structure cannot be obtained. The tarps must prevent embers from getting in or around the wood pile and be properly secured. Fire resistant tarps must display the California State Fire Marshal seal permanently attached to the tarp material. As an alternative, up to three sides of the wood pile may have 1/ 16-inch metal screen with at least a 1-inch space from the firewood. The screen shall be firmly attached to the deck rail or other approved structure, and the screen and the tarp shall completely cover and surround the wood pile. A wood box that completely surrounds the wood is also an acceptable means of compliance.
Fire Resistive Tarps
Fire retardant tarps aren’t invincible, but they protect you against a lot more than just actual fire. We’ll break down their construction, materials, and talk about the tarps you have now and whether or not they’re also fire retardant.
As protection against static electricity, UV rays, and shielding your items/structures from the elements, there’s a lot to them. It’s time to teach you everything you need to know about flame retardant tarps.
No, not by a long shot. Specific materials and chemical treatments on those materials are what make a tarp fire resistant. Cotton canvas, polyester canvas, and mesh tarps would go up like a hay bale – they do not make good fire-retardant tarps.
Instead of going up in flames and catching fire, polyethylene basically melts if it gets too hot. It doesn’t catch fire and make it spread; it must have a constant supply of intense heat for it to melt. You would have to hold a torch to it for an extended period to get it to melt, which isn’t likely to happen even on your worst days.
Embers are as hot as the fire from which they originate, and are light enough to be carried by the wind for long distances. They are also the primary reason that homes and properties ignite when there is a wildfire nearby.
It depends on the tarp, but yes, some of them can be flammable. Just to clarify what this means, they can catch fire; they’re not more prone to lighting on fire than a piece of paper, they’re just able to host fire which will continue to consume it.
This isn’t every tarp, though. Cotton canvas, mesh, polyester canvas, and a few other materials can catch fire, while polyethylene remains the best option for flame retardant chemical bonding, and natural flame resistance.
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.
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.
For more information on defensible space and where to buy fire resistive tarps, please visit our website at:
Wildland Urban Interface: https://mlfd.ca.gov/wildland-urban-interface/
Fire Resistive Tarps: https://mlfd.ca.gov/wp-content/uploads/2020/09/Woodpile-and-Tarp-Information.pdf