Abstract: An apparatus for producing decorative building material of the type in which granules of rock are bonded to a supporting net with a synthetic-resin binder, comprises a device for dipping a web of the net in a vat of the priming liquid which can consist of an aqueous dispersion or solution of the polymer containing powder of the granules. The priming coating is squeezed out and the granules are deposited on a conveyor, whereupon a spray head deposits the synthetic resin upon the granule-coated net. The latter is then passed through a drying tunnel on a conveyor through which the web is heated by gas-fired infrared heaters and the web is then compressed between rollers and cooled.