Mortar is the bonding material between bricks, concrete block, stone, and many other masonry materials.It is made from Portland cement, lime, sand, and water in varying ratios. WNYguy | Jan 25, 2008 06:29am | #9. As outlined on diydata.com, an older method of mixing mortar included portland cement, hydrated lime … Mortar mix is a critically important building component that must be combined thoroughly. Thanks. rlrefalo ... is there a more manageable ratio that we could learn to mix a lime mortar? This varies according to the needs of the task: above ground is 5:1, below ground is 3:1 and internal walls is 8:1. That works out to about 1 part lime to 3 parts sand. Each of the standard mortar mixes—Types N, M, S, and O—has different performance characteristics for different … Mortar mix for stone foundation. Natural stone is often laid in a "dry stack" style without any mortar, but mortar stabilizes the stones to keep them from falling off the wall. Laying Natural Stack Stone Using Mortar. I'd love to try this someday on a more modest scale. There are a variety of mortar mixes that the mason contractor can mix up, depending on the type of material that is being installed: Type M (2500 psi) Type S (1800 psi) Type N (750 psi) The different types are achieved by varying the ratio of Portland Cement, Lime and Sand. The type of sand and cement mixture needed will dictate the exact ratio.