Thinking about a steel building? Those in any climate with changing weather should possess a full understanding of snow and rain loads before deciding to include this structure on their property. Let us help explain each:

Design Snow Load is a number that stands for the maximum probable weight of snow that can be present on a roof of a steel building at a given time; snow load correlates specifically to location on the building. The design snow load number is impacted by the given ground snow quantity in any area. There are certain coefficients that apply to a given ground snow number to engineer a specific general steel building to achieve its correct design snow load. These factors include flat roof snow load, the ground snow load number, and thermal and exposure indications.

Generally, the roof snow load number will be less than the ground snow load number because there is some snow removed from any roof by the actions of wind and melting. Other weather related circumstances that occur such as snow sliding and snow drift have to be accounted for if they are applicable.

For design considerations, you should also be aware of the factor of unbalanced snow on gabled or hip roofs. Specific calculations for the correct loading of this design are a result of the metal building area, roof pitch, and the flat and pitched roof snow loading numbers applied to a very complicated formula.

Another term to consider when discussing snow load is that of partial loading In general, this is specified in the design of structural supports, such as purlins or a steel building frame, that use multi-span rather than clear-span construction. Some spans of the steel building, consequently, have less of a level of snow load applied while others are at a maximum level.

Rain loads have also been reintroduced into the calculations for proper roof loading. In some areas of the country, a snow storm can quickly change to rain - thus, the "rain on snow" load term. If the pitch on the roof is negligible, the water cannot drain away readily and is absorbed by the existing snow. Exaggerated roof pitches or more structural support are the answers to this heavier load.

Rain load is the weight of the water on a roof that can exist due to the drainage system being compromised. Quick rain water flow off of a roof guarantees the integrity of the residential or commercial steel building. The popularity of exterior gutters, rather than interior drains is a remedy for potential roof failure due to water weight.