The difference in mortar mixes can vary due to the size profile of the sand grains. Uniformly large grain sand will have more space between the grains than a mixture of grain sizes. Local differencs in the past, probably occur for a variety of reasons but I don't have any information. Sand is now an idustrial commodity, spec., washed and screened, vary different from what you can dig out of a bank.
Last edited by Roger Nair; 02/15/09 02:34 PM.
