Wood cement board

Abstract

Provided is a wood cement board that has a pattern of acute-angled and deep recesses and projections on its surface, and that tends not to cause cracking during a hardening and curing process, a drying process, a transportation process and so on. The wood cement board has a pattern of recesses and projections on its surface, in which the distance from the apex of the projections to the rear face is 9 mm or more, and the distance from the apex of the projections to the base point of the recesses is 2 mm or more, and is equal to or less than half the distance from the apex of the projections to the rear face. The average specific gravity of the wood cement board as a whole, and the specific gravities of the projections and the recesses are each 1.1 or more, and the difference between the specific gravity of the projections and the specific gravity of the recesses is less than 0.1.

1 . A wood cement board having a pattern of recesses and projections on its surface, and comprising a hydraulic material, a silica-containing material, and a wood reinforcement,
 wherein the distance from the apex of the projections of the wood cement board to a rear face of the wood cement board is 9 mm or more,   the distance from the apex of the projections to the base point of the recesses is 2 mm or more, and is equal to or less than half the distance from the apex of the projections to the rear face,   the average specific gravity of the wood cement board as a whole, and the specific gravities of the projections and the recesses are each 1.1 or more, and   the difference between the specific gravity of the projections and the specific gravity of the recesses is less than 0.1.   
   
   
       2 . The wood cement board according to  claim 1 ,
 wherein the wood cement board comprises a surface layer and a core layer, and   raw material mixtures of the surface layer and the core layer have different compositions, and the surface layer has a denser structure than that of the core layer.