Duckboard flooring constructed of 1" x 4" (5/8" x 3-1/2" net) S4S, kiln dried, all heart Western Red cedar tops blind fastened from beneath to a 1/2" x 3" cedar frame with 5/8" spacing between boards to allow moisture to fall thru to floor to provide a safe, effective, non-slip surface for sauna ingress and egress.