As a general rule, however, Portland cement should not be used for the repair or repointing of older buildings built in lime mortar, which require the flexibility, softness and breathability of lime if they are to function correctly.
In the United States and other countries, five standard types of mortar (available as dry pre-mixed products) are generally used for both new construction and repair.
It is therefore easier to make than lime mortar and sets up much faster which may be a reason it was used as the typical mortar in ancient, brick arch and vault construction.
Gypsum mortar is not as durable as other mortars in damp conditions.
It was invented in 1794 by Joseph Aspdin and patented on 18 December 1824, largely as a result of efforts to develop stronger mortars.
It was made popular during the late nineteenth century, and had by 1930 became more popular than lime mortar as construction material.
Gypsum mortar, also called plaster of Paris, was used in the construction of the Egyptian pyramids and many other ancient structures.
Ordinary Portland cement mortar, commonly known as OPC mortar or just cement mortar, is created by mixing powdered Ordinary Portland Cement, fine aggregate and water.
The excavation of the underground aqueduct of Megara revealed that a reservoir was coated with a pozzolanic mortar 12 mm thick. The Greeks obtained the volcanic ash from the Greek islands Thira and Nisiros, or from the then Greek colony of Dicaearchia (Pozzuoli) near Naples, Italy.
The Romans later improved the use and methods of making what became known as pozzolanic mortar and cement.
According to Roman Ghirshman, the first evidence of humans using a form of mortar was at the Mehrgarh of Baluchistan in Pakistan, built of sun-dried bricks in 6500 BCE.
The ancient sites of Harappan civilization of third millennium BCE are built with kiln-fired bricks and a gypsum mortar.