Surfboard Foam Density

Surfboard foam density measures the weight of one cubic foot of the foam in the surfboard. As foam density increases, a surfboard become harder and weighs more. Foam density depends on the size, type, use and construction of the surfboard.

  1. Function

    • Surfboard foam makes up the middle layer of the board. It allows the board to float, even with the weight of a person on top. A carver cuts the initial piece of foam, called the surfboard blank, into the shape of the board he wishes to produce.

    Wings

    • Thinner surfboards often use a higher density foam to compensate for the size. Some surfboards feature wings with foam cores to allow the surfer to maintain control when turning. Higher density foam in the wings makes them heavier, which weighs down the board, but also helps to keep the wings sturdy.

    Types

    • Polyurethane, expanded polystyrene and extruded polystyrene make up the most commonly used foam cores. Each type of foam comes in different densities, most often ranging between one and two pounds per cubic foot.