Patent ID: 8091304

Claim:
A construction board, for use in dry construction, the construction board comprising: a binding agent matrix ( 13 ) of a set, inorganic binding agent in the form of Portland cement wherein the binding matrix ( 13 ) is in the range from 10 to 40% by mass; grains of open-surfaced, expanded perlite ( 15 ) embedded into the binding agent matrix ( 13 ), wherein the grains of open-surfaced, expanded perlite ( 15 ) have a grain size in the range from 1 mm to 6 mm and the open-surfaced, expanded perlite ( 15 ) is in the range from 3 to 30% by mass; a hydrophobing agent ( 16 ) disposed on the grains of open-surfaced, expanded perlite ( 15 ); an inert filler material ( 17 ) embedded into the binding agent matrix ( 13 ), wherein the inert filler material ( 17 ) is powdered stone having a dry bulk density that is higher than a dry bulk density of the open-surfaced, expanded perlite ( 15 ) and the inert filler material ( 17 ) is in the range from 10 to 70% by mass; covering layers ( 5 , 7 ) on both main surfaces ( 9 , 11 ) of the construction board, the covering layers ( 5 , 7 ) including a set binding agent with an embedded fiber mat ( 19 , 21 ); water or residual moisture in the range from 0 to 20% by mass; and additional components in the range from 0 to 20% by mass.