ICF Earthquake Resistance
Out on the earthquake-prone West Coast, ICF comes highly recommended for its high bending load capacities and superior racking strength (don’t worry, we had to look it up too). Basically, racking refers to the lateral force created against a wall during an earthquake or high wind. In general, ICF provides 5-10 times the racking resistance of wood framed walls; you’d have to build your whole house out of 3x4 studs, use at least 1/2 sheathing, and attach everything with special hardware to match just the lowest strength ICF wall.
Out of plane bending loads refer to the forces (seismic, wind, floodwater, earth pressure) put on structure walls. ICF walls have a 200-400psf ultimate bending load, which means they can withstand wind gusts up to 395mph. In comparison, lumber’s bending load is 50-100, which equates to about 200mph wind gusts.
Science is cool, guys.