Partial wetting results in partial collapse, which is linked to the reduction in soil suction caused by wetting. The laboratory procedure presented in this paper represents a modification to the one-dimensional response-to-wetting test. These modifications are designed to provide quantitative data that can be used to estimate collapse settlements resulting from partial wetting. The sequence of wetting and loading, and its effect on the partial collapse data, are discussed. Laboratory data are presented. Application to engineering practice is addressed.