IBC 2012 1804.2, PLACEMENT OF BACKFILL 

The excavation outside the foundation shall be backfilled with soil that is free of organic material, construction debris, cobbles and boulders or with a controlled low-strength material (CLSM). The backfill shall be placed in lifts and compacted in a manner that does not damage the foundation or the waterproofing or dampproofing material.

Exception: CLSM need not be compacted.

Soils and Foundations Code Interpretation

 This section implies that backfill material shall be in accordance with code requirements. Backfill was originally addressed in the “Waterproofing and Dampproofing” section of the BOCA code. In its original form, it addressed backfill around foundations — a pertinent component of a waterproofing application. Therefore, backfill requires addressing from a waterproofing perspective. It also implies that the excavation outside of the foundation shall be backfilled with soil that is free of all organic material, construction debris and large rocks. The backfill shall be placed in lifts — no more than 8 inches in depth — and compacted in a manner that has no adverse effect on the substrate or the waterproofing or dampproofing material.