Load spreading is a term used in the context of cargo transportation and refers to the practice of distributing the weight of a load evenly over the surface area of a pallet or container. This is done to ensure that the load is secure and stable during transportation and to prevent damage to the cargo or the container. Load spreading is an important consideration when transporting heavy or large loads, as it can help to prevent accidents and ensure that the cargo arrives at its destination in good condition. In general, load spreading involves carefully arranging the cargo on the pallet or container in such a way that the weight is distributed evenly over the entire surface area,
reducing the risk of the load becoming unstable or shifting during transportation.

Load spreading helps to 

• Make the Aircraft loading easier – an evenly weighted ULD is far more manageable
• Evenly weight and balance the aircraft
• Ensure safety for all concerned, i.e. the majority of any load is not concentrated on one single pallet
• Avoid damage to the aircraft structure

Floor Bearing Capacity

Floor bearing capacity is the maximum weight that a floor or supporting surface can safely support without collapsing or being damaged. This is an important consideration when loading cargo onto a pallet or container, as the weight of the cargo must not exceed the floor bearing capacity of the surface on which it is being placed. To determine if the weight of the cargo will exceed the maximum value, the supporting surface of the piece must be calculated. This can be done by measuring the surface area of the floor or supporting surface and using this information to determine the maximum weight that can be safely placed on it. In general, it is important to ensure that the weight of the cargo does not exceed the floor bearing capacity in order to prevent accidents and damage to the cargo and the supporting surface.

The surface Calculation = Length x Width.

e.g.

A piece of freight has four separate feet with the dims of 10 cm ×  10 cm (0.1 m × 0.1 m)

The supporting surface of one foot will be 0.1 m × 0.1 m (l × w) = 0.01 m².

Four feet mean 0.01 × 4 = 0.04 m² this is the total supporting surface of that piece.

The maximum weight per sqm = 2,000 kg so to calculate the maximum weight of a piece

can weigh before spreader boards are required:

0.04 × 2000 = 80 kg.