Roof Report

Factory Mutual recently made changes that updated the Loss Prevention Data Sheets featured image

Factory Mutual recently made changes that updated the Loss Prevention Data Sheets

The following are some of the most important changes:

FM 1-9 (Roof Anchorage for Older, Wood-Roofed Buildings)

  • Changed the title to Roof Anchorage for Older, Wood-Roofed Building (from Roof Anchorage)
  • Revised the scope of the document to apply only to older, wood roofed buildings (new construction follows guidance from DS 1-28)
  • Deleted sections now addressed in 1-28
  • Connection to concrete block wall
  • Wood Framed Buildings
  • Steel Buildings with Corrugated Roof Panels
  • Permanently Open Buildings

FM 1-15 (Roof Mounted Solar PV Panels)

  • Simplified wind design guidance for PV arrays that are parallel to and within 5 to 10 in of the roof surface
  • expanded wind design guidance for sun-facing sloped PV arrays

FM 1-28 (Wind Design)

  • Deleted wind pressures table and now roof pressures can be determined using the Rating Calculator in Roof Nav.
  • Wind uplift calculator will provide wind pressures and uplift ratings for FM. Also, it gives a zone layout with perimeter and corner distances.
  • Revised design wind guidance to reflect changes in pressure coefficients and zone dimensions in ASCE 7-16.
  • A separate 100-year MRI wind map is provided for each island of Hawaii in place of one wind speed for all islands. Due to the steep terrain on much of the islands, wind speeds on the map increase with elevation.

FM 1-29 (Roof Deck Securement and Above-Deck Roof Components)

  • Updated tables and examples to reflect changes from sheet 1-28
  • changed name from field/perimeter/corners to zone 1/2/and 3
  • Added new interior Zone 1′. Zone 1′ applies to buildings when the width is >2.4H

FM 1-30 (Repair of Wind-Damaged Single and Multi-Ply Roof Systems)

  • Minor changes to reflect the latest version of sheet 1-28 including renaming field/perimeter/corner to zones 1,2, and 3
  • Added new zone 1′ roof area

FM 1-31 (Panel Roof System)

  • Revised wind guidance for consistency with changes in Data Sheet 1-28 (which includes adjustments due to prescriptive wind enhancements in Zone 2 and 3

FM 1-34 (Hail Damage)

  • This is released as an interim revision. Minor editorial changes were made.

FM1-35 (Vegetative Roof Systems)

  • Added recommendation to install vegetative roofs in areas not susceptible to wildland fire
  • increased safety factor for securing vegetative components

FM 1-49 (Perimeter Flashing)

  • Interim Revision – editorial changes made. Revisions reflected changes to the datasheet 1-28. The primary changes were renaming the field, perimeter, and corner roof areas as Zone 1, Zone 2, and Zone 3, respectively.

FM 1-52 (Field Verification of Roof Wind Uplift Resistance)

  • Added roof zone layout diagram for adjacent roofs areas at different heights
  • Added testing parameters to accommodate a new interior roof zone (zone 1′)
  • Reformatted document to simplify the implementation of testing and moved procedures for field testing and visual construction observation (VCO) to appendices