In which situation would type S mortar be preferred?

Type S mortar is formulated with a higher compressive strength and greater flexibility compared to other mortar types, making it particularly suitable for specific construction scenarios. In high wind regions, it provides enhanced resistance to lateral forces, which are prevalent due to strong gusts associated with storms and other weather conditions. This strength and ability to withstand such forces is essential when employed in cavity walls, as it helps ensure the stability and integrity of the wall system, preventing any potential failure that could arise from excessive wind pressure.

While type S mortar does have its place in low load applications, is not specifically noted for waterproofing, nor is it generally preferred in locations with minimal exposure to the elements. Other mortar types might be more advantageous in those contexts based on the specific requirements regarding strength, flexibility, and exposure to environmental stresses.