Which type of hydrated lime is best to use with Portland cement for mortar?

Type S hydrated lime is best to use with Portland cement for mortar because it enhances the strength and durability of the mortar mix. It has a higher plasticity and works well to improve the workability of the mortar, making it easier to apply and shape. This type of lime also contributes to better bonding between the cement and the aggregates, which is essential for creating a strong and durable masonry joint.

Additionally, Type S hydrated lime aids in providing resistance to water and weather-related issues, which is particularly beneficial in areas exposed to harsh environmental conditions. Using Type S lime in combination with Portland cement results in a more robust and resilient mortar, suitable for various construction applications, especially in structural and international constructions where durability is paramount.