Flat Roof Initial Sizing and Fastener Calculation Principles

The previous parts of our flat roof guide already talked about the basic concepts of planning a flat roof, described the difference between flat and pitched roofs, looked at the structure of a flat roof in more detail and explained which loads and stresses must be taken into account and which types of securing can be considered. This issue talks about initial sizing.

What Is Initial Sizing in Flat Roof Design?

An initial sizing is the basis for determining the necessary number of flat roof attachment elements. But which influencing factors play a role in the quantitative analysis, and which parameters are required to create the initial sizing?

 

Key Influencing Factors for Flat Roof Initial Sizing

With regard to the effects, three factors have an influence on the calculation: 

How Wind Zones Affect Flat Roof Fastener Calculations

The wind zone in which the building project is planned. Here the geographic location of the building plays a role. Germany, for example, is split into four wind zones. 

Terrain Categories and Surface Roughness Considerations

Four terrain categories are defined in terrain roughness. 

Building Geometry Factors in Wind Load Calculations

The building geometry with the following parameters – floor plan calculation, building height, roof slope and attack training – also must be considered.