Block Storage can be built in two different designs: the 90-degree angle stack method or the 45-degree angle method. The most common is the 90-degree angle method. It provides the greatest number of sku openings and storage positions per aisle. The 45-degree angle method offers fewer openings, but it permits narrower aisles. With floor stack storage, unit loads or containers are placed on the floor with a maximum of 6 to 10 unit loads deep per storage lane. A storage lane may be a single row or back-to-back rows. Because of leaning of unit loads and variance of unit load placement on the floor, longer storage lanes reduce lift truck deposit and productivity. Floor stack storage provides high storage density but poor accessibility. The sku in the storage lane’s aisle position is the sku for the entire storage lane. For cube (air space) utilization, unit loads are stacked on the floor unit loads. This method of stacking requires the unit load or case of goods on the floor be capable of supporting the stacking weight.