Recognizing how a safety factor is included in the approval listing is critical to ensuring an appropriate roof system is selected and installed.
Roof systems that have the tested capacity to resist calculated design wind pressures can be found in approval listings (e.g., UL, FM). Understanding the similarities and differences between the three versions of ASCE 7 provides for better recognition of the current version’s complexity and allows for more appropriate wind load determination. The progression of ASCE 7 during the last two decades had added complexity to what was once a relatively straight-forward calculation. The three versions that are currently in use are ASCE 7-05, 7-10 and 7-16, with the “-xx” representing the year of publication . Different editions of building codes exist, and therefore, different versions of ASCE 7 are being used in different parts of the country. And with the latest version of ASCE 7, “Minimum Design Loads For Buildings and Other Structures” (ASCE 7), it has become that much more challenging for roof system designers, roof system manufacturers and roofing contractors. Wind design of roof systems is one of the more complicated things that an architect deals with during the design of a building.
that under ASCE 7-05 are likely particularly in areas with high horizontal ground accelerations. Simply put, this reduced anchorage capacity greatly increases the likelihood that anchorage capacity may govern the maximum allowable brace spacing.
The over-strength factor results in a significant reduction in anchorage allowable design capacity to the extent that allowable anchor load may govern maximum allowable brace spacing.
They do not account for State or Local code amendments (if any). The differences below are directly from ASCE 7 and pertain to structures in Seismic Design Categories C, D, E and F. Per the code updates, there are some changes in the nonstructural requirements for commercial building that may affect your project. ASCE 7-05, the standard referenced in the 20 IBC, has been substituted by ASCE 7-10 in the 2012 IBC. The ASCE 7 Standard Minimum Design Loads for Buildings and Other Structures is the document the International Building Code (IBC) relies on for its structural and nonstructural requirements.