What Is the Standard Ratio of Lime, Portland Cement and Sand to Make Mortar?

What Is the Standard Ratio of Lime, Portland Cement and Sand to Make Mortar?

The standard ratio for general purpose mortar, type N mortar, is one part Portland cement, one part lime and six parts sand. Type N mortar is typically used for exterior walls above ground level that are exposed to the elements. It is also appropriate for interior load-bearing walls.

Within about a month, the strength of type N mortar is between 1500 and 2400 pounds per square inch. Other types of mortar are appropriate to different situations. For instance, type S mortar is often used underground to deal with soil pressure or seismic vibrations. Type O works for non-load bearing walls, while type M is needed for walls that support heavy loads.