Process for the preparation of an impregnated building material, and the product thereby obtained

摘要

The invention refers to a process for the preparation of a hydrofobous building material containing a ballast material and a binder added or formed in connection with the manufacture. At least part of the ballast material is or is made water-repellant and is admixed with the rest of the ingredients of the building material, the amount of water-repellant ballast material and the grain size thereof being adapted so that the water-repellant characteristics of the building material is brought to an acceptable level while maintaining a sufficient wet vapor diffusion ability.