ICFs and Severe Weather

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Severe Weather Starts its Seasonal Havoc

As we all are very aware, this time of year and throughout the early summer, is prime weather conditions for severe weather to occur. Most notably, tornadoes are a huge concern, especially in the Midwest. As of last night, tornadoes have started their annual ravaging of parts of the Midwest all the way down south. The tornadoes these last few years seem to be occurring more, bigger in size and staying on the ground longer. This brings us to the important issue of having a shelter that can withstand the winds and debris of a tornado, hurricanes, and other high wind forces. Recently Fox Blocks just publish a quick overview on how to build an ICF storm shelter, check that out with the embedded video below.

Insulated Concrete Forms Build Safer Homes

By using insulating concrete forms for homes across the country, the home becomes a safe haven from tornadoes and hurricanes. This is one of the huge benefits we have always talked about with our type of product. The steel reinforced concrete, which can cure stronger than normal concrete because of the foam insulation, can withstand winds of over 200 MPH, and projectile debris traveling over 100 MPH. There are dozens of eye witness examples of ICF homes taking EF5 tornadoes head on with the walls still standing.

There have been lab studies done to prove its resilience to wind and there are stories and real world examples of homes, across the country, that have withstood natural disasters because of the unique attributes of ICF construction.

Stronger than Wood and Steel

Plenty of third party research on testing the strength of our ICF walls versus typical wall with wood and steel studs has been done. The chart below shows the strength of ICFs, so its easy to see why ICFs are left standing after a bout with mother nature.

Axial Capacity - pressure or force placed downward upon the wall from roofs, floors and walls

Wall Bending Stiffness - the strength of the wall structure to resist deflection

Lateral Capacity - sideways movement pushing against the wall due to soil, wind or earthquakes

Deflection - movement within a wall assembly

Type of WallAxial Capacity (plf)Wall bending Stiffness (psf)Lateral Capacity (psfFire Resistance Rating
2x4 Wall Cavity @ 16" o.c.4359.537.530 min-1hr
2x6 Wall Cavity @ 16" o.c.3220378030 min-1hr
6" Core ICF Wall #4 @ 24" o.c.22,000300653 hours