Geofoam FAQ
A car weighs approximately 4,000lbs that’s 1,000 lbs per tire, one tire sits on about 6” X 8” or 48 square inches Type I EPS foam in 48 sq inches can support 480 lbs, however drive the car on to 2 sheets of 4 x 8 OSB, 2 tires on each, now 32 square feet of foam is supporting the ½ the car or 2000lbs, 32 X 144 = 4,608 square inches or 46,080 lbs.
To stay at or below 1% deformation – 1lb foam supports 3.5 pounds per square inch. 10ft x 10ft slab of concrete weights 50lbs per square ft X 100 Square feet = 5,000 lbs. 100 square feet of Type I foam can support 50,400 pounds (100*144*3.5 lbs per sqin) at 1% deformation. One full size king cab 4 wheel drive pickup truck can weigh 12600 lbs. Parked on 10ft x 10 ft slab the total weight is 17,600 lbs well below the 50,400 lbs 100 square feet of 1 lb. EPS can support with 1% deformation or less.