Concrete basement walls are designed to do two main jobs. One job is supporting the house; the other is holding back the pressure of soil against the side of the basement. Considering the nature of concrete, holding up the weight of the house is the lesser worry. Concrete's compressive strength is much greater than it needs to be to support a house. This article explains how wall thickness, rebar, and proper drainage all affect the ability of poured concrete foundation walls to resist lateral soil pressure.