IBHS Forest Fire Test Exposes Building Vulnerabilities

In March 2019, the Insurance Institute for Business & Home Safety (IBHS), at its test facility in South Carolina, exposed a fullscale building—one half with fire-resistant materials, and the other half as a traditional bungalow—to a 10-minute windstorm of driven embers. The amazing results can be viewed at https://ibhs.org/wildfire/wildfire-demo-2019/.

One half of the house was built with cedar siding, vinyl gutters, single-pane windows, and bark mulch around the foundation. The other side had fiber cement siding, metal gutters, double-pane windows, and gravel around its foundation. Blowing embers that get a head start in combustible materials are the leading cause of wildfire ignition, IBHS researchers claim.

The IBHS recommends that eaves be closed and vents covered with ⅛-in. mesh rather than the ¼-in mesh often used. Deck joists should be topped with foil-faced bitumen tape wrapped partially down the sides under the planks, its research engineers opine.