FMG128.xls

"FMG128" is a spreadsheet program written in MS-Excel for the purpose of determining Factory Mutual Global (FMG) required roof zone ratings for the three (3) zones of a roof, based on FMG Data Sheet 1-28 (2009/2011).
This program is a workbook consisting of two (2) worksheets, described as follows:
Doc
FMG Roof Uplift Ratings - Roof Wind Uplift Pressure Ratings per Factory Mutual Global 1-28
Program Assumptions and Limitations:
1.  This program is based on the following reference:
         Data Sheet 1-28: "Wind Design" - by Factory Mutual Global, 2009 (Revised April 2011)
2.  In the "FMG Roof Uplift Ratings" worksheet, the FMG roof Zone 1 (Field Area) Rating is determined as follows:
     a. Get Field Area design pressure from either Table 3, 4, or 5 depending on the Exposure, either B, C, or D.
     b. Apply multiplier for Zone 1 from Table 6.
     c. Apply a Factor of Safety multiplier of 2.
     d. Round value up to the next highest 15 psf rating interval to arrive at the FMG Zone 1 (Field Area) Rating.
     Note: for Zone 2 (Perimeter) and Zone 3 (Corners)
3.  In the "FMG Roof Uplift Ratings" worksheet, the FMG roof Zone 2 (Perimeter) Rating is determined as follows:
     a. Get Field Area design pressure from either Table 3, 4, or 5 depending on the Exposure, either B, C, or D.
     b. Apply multiplier for Zone 2 from Table 6.
     c. Apply a Factor of Safety multiplier of 2.
     d. Round value up to the next highest 15 psf rating interval to arrive at the FMG Zone 2 (Perimeter) Rating.
4.  In the "FMG Roof Uplift Ratings" worksheet, the FMG roof Zone 3 (Corners) Rating is determined as follows:
     a. Get Field Area design pressure from either Table 3, 4, or 5 depending on the Exposure, either B, C, or D.
     b. Apply multiplier for Zone 3 from Table 6.
     c. Apply a Factor of Safety multiplier of 2.
     d. Round value up to the next highest 15 psf rating interval to arrive at the FMG Zone 3 (Corners) Rating.
5.  For components and cladding (roof deck, fasteners, and above deck components), FMG 1-28 requires that the effective area be set = 10 ft.^2 along with an Importance Factor = 1.15.  For secondary supporting members (purlins or joists) per FMG 1-28 Section 2.2.3,  refer to applicable ASCE 7 Standard and apply the appropriate effective tributary area along with an Importance Factor = 1.15.
6.  This program contains numerous “comment boxes” which contain a wide variety of information including explanations of input or output items, equations used, data tables, etc.  (Note:  presence of a “comment box” is denoted by a “red triangle” in the upper right-hand corner of a cell.  Merely move the mouse pointer to the desired cell to view the contents of that particular "comment box".)

Calculation Reference
Roof Wind Uplift Pressure
Factory Mutual Global
Wind Loads