A cement board is a mixture of cement and reinforcing fibres formed into (6.4 to 12.7 mm) thick that are typically worked as a tile buttress board. Cement board can be held or screwed to wood or steel studs to build a substrate for vertical tile and connected horizontally to plywood for tile floors, kitchen tables and backsplashes. It can be used on the exterior of homes as a base for exterior plaster (stucco) systems and seldom as the finish system