The goal is to determine the mechanisms of soil-cement interlocked brick plus wood fibers under compressive loading. For this we used experimental stress analysis techniques. Horizontal deformations (εx) and vertical (εy) of bricks were obtained with extensometers, in the configuration of five rosettes. From the values of these deformations and using the equations of the theory of elasticity, Poisson coefficients were determined and elasticity modules, and calculated the corresponding voltages each escutcheon according to the equations of the State of plane stress. To determine the trajectory of the rupture voltage-loading graphics were made of each rosette. Knowing this trajectory determined the tensions related to the modification of the brick break mechanism. The appearance of a premature cracking or excessive is parameter used to determine the State limit of use of bricks.