Crushed stone 3/4'' clear is a drainage stone. Can be used in cement-sand mix to make concrete. Serves as finishing for raised shed, as underlay for concrete slabs (garage) and fill for agricultural drain.
The D.B. certificate is a document certifying that the backfill stone used has been verified by the producer (quarry) as compliant for use under a concrete slab.
The "problem of pyrite" is used to describe the phenomenon of swelling of certain embankments used in residential construction. Pyrite, an iron sulphide mineral, is found in several rock formations, including shale, a soft, clay-like sedimentary rock that may have been used as backfill under subgrade foundation slabs. floors and garages. Problems with pyrite can appear ten years after the construction of the house, because, generally, the phenomenon evolves slowly, but it can also be very fast or very slow, appearing only after 15, 20 or even more than 25 years.
Fees are required for any D.B. certificate application
(minimum order of 20 tonnes is required).