Granulated and sieved boiler slag is very suitable as paving sand. In privately used areas, such as garage driveways, sieved material with a fine grain size can be used; for heavy-load applications, such as industrial areas with truck traffic, crushed and dried raw material must be used.
Boiler slag does not contain organic substances, such as pollen or spores that might cause the growth of weeds between the paving stones. Furthermore, the material has a very good drainage effect. This is useful especially in winter, because the ground is not lifted by frost.
Granulated boiler slag is recommended for use with permeable paving stones because it supports the drainage effect of the stones so that the water can flow away better than on other surfaces.