Characterization based on samples obtained in conventional field investigations is an important step in obtaining engineering properties for use in selecting foundation type and making design decision. A practical method for classification and estimating expansive soils behavior is described through application to three sites. The method is based on suction testing expansive clay samples and is suitable for routine use in geotechnical testing laboratories. In this paper, three cases are reviewed and the experience discussed. The use of relatively simple suction testing of soils is a valuable addition to routine geotechnical investigations of expansive soils