The cedar boards are 8″ high and 1 1/2″ thick. Four seats come with pre-drilled holes and stainless steel screws that won’t rust. The sandbox is easily assembled, using mortise and tenon joints that won’t pull apart.  This sandbox is made from non-toxic, untreated eastern white cedar.  The wood is cut to 4' and 6' with the Mortise and Tenon joint giving your kids about 3' by 5' of inside play space.  Need more area? The Aluminum Pin Joint style will give  you just under 4' by 6' of play area.