A Treehouse board is a unique construction:

XPS foam: fully recyclable, isocyanate free, water-proof cell structure.
Australian Hoop Pine and fibreglass composite skin: plantation grown timber laminate vacuum formed with fibreglass using a water catylised glue.
Feature timbers: reclaimed Australian hardwoods.
Laminated, as opposed to solid timber rails: keep our boards light weight.
Solvent-free clear epoxy finish: lower emissions of volatile organic compounds than polyester resins.
Less than a third of the amount of resin used in standard surfboard construction.