Blocks are commonly used as walling units, which act as forms of bracing to structural frames by providing lateral stability to structures. Some structural failures have been recorded as a result of poor quality blocks produced by commercial block producers who make arbitrary choice of mix proportions. There is need to estimate the durability of these blocks. Water absorption is considered as a useful measure of durability of building/ construction materials. There is not much information on water absorption properties of sand-laterite blocks. The general/conventional methods of mix proportioning to achieve this desired property have some limitations with respect to time, energy and money spent. In this work, a model based on Scheffe’s simplex method, for prediction of the water absorption property using different mix proportions of the blocks was formulated, The model equation was tested for adequacy using the student’s t-test and the fisher test. As this paper presents the absorption property of sand-laterite blocks made by replacing commonly used river sand by laterite partially, there will be reduced dependence on river sand which is costly and scarce (in some areas), in block production. This will lead to reduction in production cost of blocks and consequently housing units will be affordable by most individuals.