What is the maximum minimum snow load for low-slope roofs?

The maximum minimum snow load for low-slope roofs is established based on load design criteria as outlined in building codes, particularly the ASCE 7 (American Society of Civil Engineers). This code provides guidelines on how to calculate snow loads depending on specific conditions, such as roof slope and geographic location.

For low-slope roofs, which generally have a slope of 3:12 or less, the specified minimum snow load is typically determined to be 20 times the importance factor (Is). This importance factor accounts for the significance of the structure; for instance, buildings that are essential for safety and function may have a higher importance factor, which directly influences loading criteria.

The designation of 20Is as the minimum snow load for low-slope roofs ensures that adequate capacity is designed to withstand potential snow accumulation, considering the unique challenges that low-slope roofs face regarding snow removal and drainage. In contrast, other values like 15Is, 25Is, or 30Is do not align with the standards prescribed in the relevant codes for low-slope conditions, making 20*Is the correct and justifiable choice.