The Ontario Building Code | Backfilling
4.2.5.8. Backfilling
(1) Where an excavation is backfilled, the backfill shall be placed so as to,
(a) provide lateral support to the soil adjacent to the excavation, and
(b) prevent detrimental movements.
(2) The material used as backfill or fill supporting a footing, foundation or a floor on gradeshall be of a type that is not subject to detrimental volume change with changes in moisture content and temperature.
4.2.6. Shallow foundations