Insulating concrete forms resist fires in several ways. The most obvious is their structural concrete core that will not weaken, warp, twist, or burn regardless of the fire’s heat. In so called “fire-wall” tests, ICF walls are subjected to continuous gas flames and temperatures of up to 2000 degrees Fahrenheit (1093 degrees Celsius) for as long as 4 hours. All of the leading ICF brands took the heat without any sign of weakening. In contrast, wood frame walls typically collapse in an hour or less. Note that these tests were performed on monolithic, or flat-wall ICFs, with no breaks in the concrete layer. Screen-grid ICFs have fire ratings of two hours or less.
The concrete core also prevents fire by slowing the conduction of heat from one side of the wall to the other. In PCA fire tests, ICF wall segments did not allow enough heat through to start a fire on the cool side of the wall for 2-4 hours. Contrary to popular belief, the form used in ICFs will not burn. It will melt if exposed to high heat, but it will not contribute any fuel to the fire. In fact, it is virtually “self-extinguishing”, thanks to a flame retardant all of the leading ICF manufactures add to the EPS foam.
The PCA conducted a flam spread test, and found that ICF foam is five times better than wood. They used the “Steiner Tunnel Test” to compare the two materials. In the test, technicians lined a tunnel with the test material, ran a fire at one end, then measured how far the flames spread. “The flames travel about one-fifth as far down a tunnel lined with ICF foams as they spread down a tunnel lined with wood”, the PCA report states. The PCA also reports that smoke creaked by melting EPS is ‘no more toxic’ than burning wood, based on a review of existing studies conducted by The Southwest Research Institute. Studies by Reward Wall Systems report “less than half the toxins” of burning pine.
Of course, those who live in fire-prone areas are wise to take additional steps in addition to ICF walls. Aledort, the Rancho Bernardo homeowner, used several, including sturdy windows and fire-resistant exterior finishes and roofing. Fiber-cement siding, stucco, and masonry are a few popular fire-proof finish options. Landscaping can also play a major role in keeping your home safe from wildfire.
On the inside, smoke detectors, automatic sprinkler systems, and steel wall studs can reduce the risk of interior fires getting out of control.
From Article Published by ‘ICF Builder’ in the (August/ September 2008) edition, volume 4 number 4.
To read the full article please visit www.icfmag.com