North Carolina General Contractors Practice Exam

The recommended type of hydrated lime for use in mortar mixes is Type S. Type S hydrated lime, also known as cement lime, has high bond strength and provides excellent workability and durability in mortar applications. Its properties improve the overall strength and adhesion of the mortar, making it particularly suitable for masonry work.

Type S lime contains a higher percentage of calcium oxide compared to Type N, which gives it superior structural performance. This makes it an effective choice for various types of masonry construction, especially where a higher strength and durability of the mortar binder is required.

In contrast, the other types of lime may not offer the same advantages for mortar mixes. Type N is often used in non-structural applications and may not provide the necessary strength for more demanding projects. Type L and Type M possess specific properties that do not align with the requirements needed for traditional mortar applications. Type M, while having a high compressive strength, is typically used in very specialized applications, not standard mortar. Thus, for optimal performance in mortar mixes, Type S is clearly the best choice.