binder may be present on the upper side of the pieces 11 it is also largely apparent that there are no air pockets 15 in the second layer of binder 9 nor in the second layer of aggregate 11 possibly with the exception of the lower regions thereof the mechanical processing and orientation of the individual particles or pieces 11 proceeds such that these are subjected to forces which are substantially parallel with the upper defining surface of the flooring this will cause the individual particles to turn to the positions illustrated in fig3 the mechanical processing also entails that the individual particles are acted on by forces that are directed downwards towards the substrate 1 so that the particles will thereby be u201c kneaded down u201d into the binder 9 which as a result may float up to the top side of the individual pieces 11 and form the upper thin layer 14 during the mechanical processing of the upper layer of aggregate material the lower layer of aggregate material functions as an arrest surface which prevents individual particles 11 or pieces in the upper layer of aggregate material from being depressed too far down so that the layer thickness in the flooring in the process of being formed locally may become too slight or that in a later stage a grinding down to an excessive grinding depth is.