Current prescriptive design tables used for most residential concrete basement walls are based on the presumption that the soil used for backfill does not have a lateral pressure greater than 30 psff (pounds per square foot of wall surface per vertical foot of wall). However, the only soils that produce lateral pressures at or near 30 psff are clean gravels and sands. The remaining soil types all generate higher lateral soil pressures ranging from 36 to 55 psff.

Typically, the soil excavated on a site for a residential basement is used as backfill. This soil usually is silty sand, clayey sand, silt, or clay - all soil types that produce lateral pressures greater than 30 psff. What this means is that the concrete contractor and producer often unknowingly build a structure whose design is not based on a rational approach. Unless the residential contractor builds in an area where the excavated soil used as backfill is a clean gravel or sand, the basement wall probably will receive a lateral earth load greater than 30 psff and potentially experience cracking.

The National Ready Mixed Concrete Association has proposed new plain-concrete basement-wall thickness design tables that are based on accepted engineering principles for various recognized soil types. Using the tables, a municipality can adopt one or more equivalent fluid pressures to represent the prevailing soil types in its area. This would allow the same ease of basement-wall thickness selection as with previous tables, but the wall thickness would be based on a rational approach and would be suitable for use with a much wider range of soil types.