In his guide, he details the difference between XPS (expanded polystyrene) and EPS (extruded polystyrene) and how each product’s closed cell and open cell nature affects the final board.

Description: Fanfold DWB Damproofing Waterproofing Board is an extruded polystyrene foam layer sandwiched between two tough, non-perforated, impact resistant plastic facers. Fanfold DWB is used to ...

The boards are often oriented strand board (OSB), and the foam is either polystyrene foam (EPS), extruded polystyrene foam (XPS), or polyurethane foam. Other materials may also be used including ...