ISO 4355:2013 PDF Download

ISO 4355:2013 is a standard that provides methods for determining the snow load on roofs. It serves as a basis for national codes used in determining snow load on roofs. The standard recommends that national codes should provide statistical data in the form of zone maps, tables, or formulas for the snow load on the ground. The shape coefficients provided in the standard are prepared for design applications and can be directly adopted for use in national codes unless there is justification for using different values.

For roofs with unusual or non-standard shapes, the standard advises conducting special studies such as testing scale models in a wind tunnel or water flume. These studies should include methods of accounting for local meteorological statistics and accumulation phenomena. The standard provides examples of numerical methods, scale model studies, and statistical analysis methods in Annex G.

The annexes of the standard, which describe methods for determining characteristic snow load on the ground, exposure coefficient, thermal coefficient, and loads on snow fences, are for information purposes only due to limited documentation and available scientific results. It is important to note that severe load conditions caused by unusual weather conditions in a single winter may not be accounted for in ISO 4355:2013.

However, the standard does not specify standard procedures and instrumentation for measurements.