If a floor has a weight limit of 700 pounds per square foot and a load is calculated at 900 pounds per square foot, what action is required?

If a floor has a weight limit of 700 pounds per square foot and a load is calculated at 900 pounds per square foot, what action is required?

• A. Lower the load at a slower rate
• B. Install cribbing to increase surface bearing area
• C. Install cribbing to decrease surface bearing area
• D. Install cribbing to maintain the same amount of surface bearing area

Answer: (B)

The main idea is that the floor can support a certain amount of weight per unit area, and if the load per area is higher than that, you must spread the load over a larger bearing surface. Here the floor limit is 700 pounds per square foot, but the load is 900 pounds per square foot. To bring the pressure down to or below 700 psf, you need to increase the bearing area under the load. Cribbing accomplishes this by creating a larger, stable base, distributing the weight over more surface area. So installing cribbing to increase surface bearing area is required. For example, increasing the footprint so the load per area drops from 900 psf to below 700 psf ensures the floor isn’t overloaded. Lowering the rate of lowering doesn’t address the static overloading, and decreasing or keeping the same area would keep the pressure above the limit.

The main idea is that the floor can support a certain amount of weight per unit area, and if the load per area is higher than that, you must spread the load over a larger bearing surface. Here the floor limit is 700 pounds per square foot, but the load is 900 pounds per square foot. To bring the pressure down to or below 700 psf, you need to increase the bearing area under the load. Cribbing accomplishes this by creating a larger, stable base, distributing the weight over more surface area. So installing cribbing to increase surface bearing area is required. For example, increasing the footprint so the load per area drops from 900 psf to below 700 psf ensures the floor isn’t overloaded. Lowering the rate of lowering doesn’t address the static overloading, and decreasing or keeping the same area would keep the pressure above the limit.